/* ==========================================================================
   Apps SDK UI Design System — Mobile-First & Outlook-Style Webmail
   Inspired by: https://github.com/openai/apps-sdk-ui
   ========================================================================== */

:root, [data-theme="light"] {
  /* Apps SDK UI Light Palette */
  --gray-0: #ffffff;
  --gray-25: #fcfcfc;
  --gray-50: #f9f9f9;
  --gray-75: #f3f3f3;
  --gray-100: #ededed;
  --gray-150: #dfdfdf;
  --gray-200: #cdcdcd;
  --gray-250: #b9b9b9;
  --gray-300: #afafaf;
  --gray-350: #9f9f9f;
  --gray-400: #8f8f8f;
  --gray-450: #767676;
  --gray-500: #5d5d5d;
  --gray-550: #4f4f4f;
  --gray-600: #414141;
  --gray-650: #393939;
  --gray-700: #303030;
  --gray-750: #282828;
  --gray-800: #212121;
  --gray-850: #1c1c1c;
  --gray-900: #181818;
  --gray-925: #161616;
  --gray-950: #131313;
  --gray-975: #101010;
  --gray-1000: #0d0d0d;

  --black: #000000;
  --white: #ffffff;

  /* Semantic Light Tokens */
  --color-bg-base: #ffffff;
  --color-surface: #ffffff;
  --color-surface-subtle: var(--gray-25);
  --color-surface-hover: var(--gray-50);
  --color-surface-active: var(--gray-100);
  --color-surface-elevated: #ffffff;

  --color-border: var(--gray-150);
  --color-border-subtle: var(--gray-100);
  --color-border-strong: var(--gray-300);
  --color-border-focus: var(--gray-1000);

  --color-text: var(--gray-1000);
  --color-text-secondary: var(--gray-600);
  --color-text-tertiary: var(--gray-450);
  --color-text-inverse: #ffffff;

  --color-primary-bg: #0d0d0d;
  --color-primary-text: #ffffff;
  --color-primary-hover: #262626;

  --color-btn-sec-bg: #ffffff;
  --color-btn-sec-border: var(--gray-150);
  --color-btn-sec-text: var(--gray-1000);
  --color-btn-sec-hover: var(--gray-50);

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 12px 24px -4px rgba(0, 0, 0, 0.06);
}

[data-theme="dark"] {
  /* Apps SDK UI Dark Palette */
  --gray-0: #000000;
  --gray-25: #09090b;
  --gray-50: #121215;
  --gray-75: #161619;
  --gray-100: #18181b;
  --gray-150: #222226;
  --gray-200: #27272a;
  --gray-250: #323238;
  --gray-300: #3f3f46;
  --gray-350: #52525b;
  --gray-400: #71717a;
  --gray-450: #8a8a93;
  --gray-500: #a1a1aa;
  --gray-550: #b5b5bc;
  --gray-600: #d4d4d8;
  --gray-650: #dedee2;
  --gray-700: #e4e4e7;
  --gray-750: #ececee;
  --gray-800: #f4f4f5;
  --gray-850: #f8f8f9;
  --gray-900: #fafafa;
  --gray-925: #fcfcfc;
  --gray-950: #fdfdfd;
  --gray-975: #fefefe;
  --gray-1000: #ffffff;

  --black: #ffffff;
  --white: #000000;

  /* Semantic Dark Tokens */
  --color-bg-base: #09090b;
  --color-surface: #09090b;
  --color-surface-subtle: #121215;
  --color-surface-hover: #18181b;
  --color-surface-active: #27272a;
  --color-surface-elevated: #141417;

  --color-border: #27272a;
  --color-border-subtle: #1a1a1d;
  --color-border-strong: #3f3f46;
  --color-border-focus: #ffffff;

  --color-text: #f4f4f5;
  --color-text-secondary: #a1a1aa;
  --color-text-tertiary: #71717a;
  --color-text-inverse: #09090b;

  --color-primary-bg: #f4f4f5;
  --color-primary-text: #09090b;
  --color-primary-hover: #e4e4e7;

  --color-btn-sec-bg: #121215;
  --color-btn-sec-border: #27272a;
  --color-btn-sec-text: #f4f4f5;
  --color-btn-sec-hover: #18181b;

  /* Shadows Dark */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.5);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 12px 24px -4px rgba(0, 0, 0, 0.6);
}

:root {
  /* Typography & Weights */
  --font-sans: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans", "Helvetica", "Arial", sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", "SF Mono", "Menlo", "Consolas", monospace;

  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  /* Radius Tokens */
  --radius-2xs: 2px;
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 10px;
  --radius-xl: 12px;
  --radius-2xl: 16px;
  --radius-full: 9999px;
}

/* Base & Resets */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html, body {
  height: 100%;
  background-color: var(--color-bg-base);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
}

input, button, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

::-webkit-scrollbar {
  width: 5px;
  height: 5px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--gray-200);
  border-radius: var(--radius-full);
}

/* App Layout */
.app-layout {
  display: flex;
  min-height: 100vh;
  background-color: var(--color-bg-base);
  position: relative;
}

/* Sidebar */
.sidebar {
  width: 250px;
  background-color: var(--color-surface);
  border-right: 1px solid var(--color-border-subtle);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  padding: 20px 14px;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  z-index: 100;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.sidebar-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.brand-wrapper {
  padding: 2px 6px;
  display: flex;
  align-items: center;
}

.brand-wrapper a {
  display: flex;
  align-items: center;
  width: 100%;
}

/* Dual-theme logo display */
.logo-theme-light {
  display: block;
}
.logo-theme-dark {
  display: none !important;
}

[data-theme="dark"] .logo-theme-light {
  display: none !important;
}
[data-theme="dark"] .logo-theme-dark {
  display: block !important;
}

.brand-logo {
  height: 24px;
  width: auto;
  max-width: 170px;
  display: block;
  object-fit: contain;
}

.sidebar-close-btn {
  display: none;
  background: transparent;
  border: none;
  color: var(--color-text);
  cursor: pointer;
  padding: 6px;
  border-radius: var(--radius-md);
}

.sidebar-section-title {
  font-size: 11px;
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0 12px;
  margin-bottom: 8px;
}

.btn-compose {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background-color: var(--color-primary-bg);
  color: var(--color-primary-text);
  border: 1px solid var(--color-primary-bg);
  font-weight: var(--font-weight-medium);
  font-size: 14px;
  padding: 10px 16px;
  border-radius: var(--radius-md);
  text-decoration: none;
  box-shadow: var(--shadow-xs);
  transition: background-color 0.15s ease, border-color 0.15s ease;
  margin-bottom: 24px;
}

.btn-compose:hover {
  background-color: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  color: var(--color-primary-text);
}

.nav-section {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex-grow: 1;
}

.nav-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 9px 12px;
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  font-size: 13.5px;
  font-weight: var(--font-weight-normal);
  transition: background-color 0.12s ease, color 0.12s ease;
}

.nav-link:hover {
  background-color: var(--color-surface-hover);
  color: var(--color-text);
}

.nav-link.active {
  background-color: var(--color-surface-active);
  color: var(--color-text);
  font-weight: var(--font-weight-semibold);
}

.nav-link-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.badge-count {
  background-color: var(--color-primary-bg);
  color: var(--color-primary-text);
  font-size: 11px;
  font-weight: var(--font-weight-semibold);
  padding: 2px 7px;
  border-radius: var(--radius-full);
}

/* Sidebar Quota Widget */
.sidebar-quota-widget {
  margin-top: auto;
  margin-bottom: 12px;
  padding: 10px 12px;
  background-color: var(--color-surface-subtle);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.quota-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 11.5px;
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
}

.quota-percent {
  font-weight: var(--font-weight-semibold);
  color: var(--color-text);
  font-variant-numeric: tabular-nums;
}

.quota-progress-track {
  width: 100%;
  height: 6px;
  background-color: var(--color-border);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.quota-progress-fill {
  height: 100%;
  background-color: var(--color-primary-bg);
  border-radius: var(--radius-full);
  transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.quota-progress-fill.warning {
  background-color: #f59e0b;
}

.quota-progress-fill.critical {
  background-color: #ef4444;
}

.quota-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 11px;
  color: var(--color-text-tertiary);
  font-variant-numeric: tabular-nums;
}

.sidebar-user {
  padding-top: 14px;
  border-top: 1px solid var(--color-border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-shrink: 0;
  margin-top: 8px;
}

.user-meta {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  max-width: 155px;
}

.user-email {
  font-size: 12.5px;
  font-weight: var(--font-weight-medium);
  color: var(--color-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.user-status {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  color: var(--color-text-tertiary);
  margin-top: 2px;
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-primary-bg);
}

.sidebar-user-actions {
  display: flex;
  align-items: center;
  gap: 4px;
}

.theme-toggle-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  padding: 0;
  border-radius: var(--radius-md);
  background-color: transparent;
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all 0.15s ease;
}

.theme-toggle-btn:hover {
  background-color: var(--color-surface-hover);
  color: var(--color-text);
  border-color: var(--color-border-strong);
}

.theme-toggle-btn svg {
  display: block;
}

/* Theme toggle icon switching */
[data-theme="dark"] .theme-icon-moon {
  display: none !important;
}
[data-theme="dark"] .theme-icon-sun {
  display: block !important;
}
[data-theme="light"] .theme-icon-moon {
  display: block !important;
}
[data-theme="light"] .theme-icon-sun {
  display: none !important;
}

.auth-top-actions {
  position: absolute;
  top: 20px;
  right: 20px;
  z-index: 50;
}

.btn-logout {
  background: transparent;
  border: none;
  color: var(--color-text-tertiary);
  cursor: pointer;
  padding: 7px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.btn-logout:hover {
  background-color: var(--color-surface-hover);
  color: var(--color-text);
}

.sidebar-backdrop {
  display: none;
}

/* Main Content Area */
.main-wrapper {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  height: 100vh;
  overflow: hidden;
  background-color: var(--color-bg-base);
}

.top-header {
  height: 56px;
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border-subtle);
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-shrink: 0;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.mobile-nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 6px;
  cursor: pointer;
  color: var(--color-text);
}

.header-title {
  font-size: 17px;
  font-weight: var(--font-weight-semibold);
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

.mobile-compose-header-btn {
  display: inline-flex;
  padding: 7px 14px;
  font-size: 13px;
}

/* Perspective Switcher */
.view-perspective-switch {
  display: flex;
  align-items: center;
  background-color: var(--color-surface-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 2px;
  gap: 2px;
}

.perspective-btn {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  border-radius: var(--radius-xs);
  color: var(--color-text-tertiary);
  cursor: pointer;
  transition: all 0.15s ease;
}

.perspective-btn:hover {
  color: var(--color-text);
}

.perspective-btn.active {
  background-color: var(--color-surface);
  color: var(--color-text);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);
}

/* Filter Bar */
.inbox-filter-bar {
  height: 44px;
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border-subtle);
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-shrink: 0;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.filter-pills {
  display: flex;
  align-items: center;
  gap: 6px;
}

.filter-pill {
  padding: 4px 12px;
  border-radius: var(--radius-full);
  border: 1px solid transparent;
  background: transparent;
  color: var(--color-text-secondary);
  font-size: 12.5px;
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: all 0.15s ease;
  display: flex;
  align-items: center;
  gap: 6px;
}

.filter-pill:hover {
  background-color: var(--color-surface-hover);
  color: var(--color-text);
}

.filter-pill.active {
  background-color: var(--color-surface-active);
  color: var(--color-text);
  font-weight: var(--font-weight-semibold);
}

.filter-unread-badge {
  background-color: var(--color-primary-bg);
  color: var(--color-primary-text);
  font-size: 10px;
  padding: 1px 6px;
  border-radius: var(--radius-full);
}

.inbox-status-info {
  font-size: 11.5px;
  color: var(--color-text-tertiary);
}

/* Search Box */
.search-box {
  display: flex;
  align-items: center;
  gap: 8px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 6px 12px;
  width: 100%;
  max-width: 320px;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.search-box:focus-within {
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 1px var(--color-border-focus);
}

.search-box svg {
  color: var(--color-text-tertiary);
  flex-shrink: 0;
}

.search-box input {
  border: none;
  background: transparent;
  outline: none;
  font-size: 13px;
  color: var(--color-text);
  width: 100%;
}

.search-box input::placeholder {
  color: var(--color-text-tertiary);
}

.search-clear-btn {
  background: transparent;
  border: none;
  color: var(--color-text-tertiary);
  cursor: pointer;
  padding: 2px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  transition: color 0.15s ease, background-color 0.15s ease;
  flex-shrink: 0;
}

.search-clear-btn:hover {
  color: var(--color-text);
  background-color: var(--color-surface-hover);
}

/* Outlook Dual-Pane / 3-Column Container */
.outlook-container {
  flex: 1;
  display: flex;
  min-height: 0;
  height: calc(100vh - 100px);
  background-color: var(--color-surface);
}

.outlook-list-pane {
  display: flex;
  flex-direction: column;
  height: 100%;
  overflow: hidden;
  background-color: var(--color-surface);
  flex-shrink: 0;
  border-right: 1px solid var(--color-border-subtle);
}

.outlook-reading-pane {
  flex: 1;
  overflow-y: auto;
  background-color: var(--color-surface);
  min-width: 0;
}

/* Perspective: Split View */
.outlook-container.view-split .outlook-list-pane {
  width: 390px;
}

.outlook-container.view-split .outlook-reading-pane {
  display: flex;
  flex-direction: column;
}

/* Perspective: Full List View */
.outlook-container.view-list .outlook-list-pane {
  width: 100%;
}

.outlook-container.view-list .outlook-reading-pane {
  display: none;
}

/* Messages List Styling */
.messages-list {
  flex: 1;
  overflow-y: auto;
  min-height: 0;
  list-style: none;
  margin: 0;
  padding: 0;
}

.messages-list li {
  border-bottom: 1px solid var(--color-border-subtle);
}

.message-item {
  display: flex;
  align-items: center;
  padding: 12px 18px;
  gap: 14px;
  text-decoration: none;
  color: var(--color-text-secondary);
  transition: background-color 0.12s ease;
  position: relative;
}

.message-item:hover {
  background-color: var(--color-surface-hover);
}

.message-item.unread {
  background-color: var(--color-surface-subtle);
  color: var(--color-text);
}

.message-item.active-reading {
  background-color: var(--color-surface-active);
  color: var(--color-text);
  border-left: 3px solid var(--color-border-focus);
}

.unread-indicator {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-primary-bg);
  flex-shrink: 0;
}

.avatar {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-full);
  background-color: var(--color-surface-active);
  color: var(--color-text);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: var(--font-weight-semibold);
  font-size: 12px;
  flex-shrink: 0;
}

.msg-content-col {
  flex-grow: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.msg-top-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

/* O Assunto do e-mail é o destaque principal */
.msg-subject-prominent {
  font-weight: var(--font-weight-medium);
  font-size: 14.5px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  color: var(--color-text);
  line-height: 1.3;
}

.message-item.unread .msg-subject-prominent {
  font-weight: 700;
  color: var(--gray-1000);
}

/* Trecho breve do conteúdo do e-mail (snippet preview) */
.msg-body-preview {
  font-size: 12.5px;
  color: var(--color-text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  line-height: 1.35;
  margin: 1px 0;
}

.message-item.unread .msg-body-preview {
  color: var(--color-text);
  font-weight: 500;
}

/* Metadados inferiores: Remetente discreto */
.msg-meta-bottom {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-top: 1px;
}

.msg-sender-subtle {
  font-size: 11.5px;
  color: var(--color-text-tertiary);
  font-weight: 400;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 100%;
}

.msg-date {
  font-size: 11.5px;
  color: var(--color-text-tertiary);
  white-space: nowrap;
  flex-shrink: 0;
}

/* Empty State */
.empty-state {
  padding: 64px 24px;
  text-align: center;
  color: var(--color-text-tertiary);
}

.empty-state svg {
  margin-bottom: 16px;
  color: var(--gray-300);
}

.empty-state h3 {
  font-size: 16px;
  font-weight: var(--font-weight-semibold);
  color: var(--color-text);
  margin-bottom: 6px;
}

.empty-state p {
  font-size: 13px;
  color: var(--color-text-secondary);
}

/* Reading Pane Content */
.reading-pane-placeholder {
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--color-text-tertiary);
  padding: 40px;
  text-align: center;
  gap: 12px;
}

.reading-pane-placeholder svg {
  color: var(--gray-300);
}

.reading-pane-content {
  padding: 24px 32px;
}

.reading-pane-header {
  border-bottom: 1px solid var(--color-border-subtle);
  padding-bottom: 20px;
  margin-bottom: 24px;
}

.reading-pane-toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
}

.reading-pane-subject {
  font-size: 20px;
  font-weight: var(--font-weight-bold);
  color: var(--color-text);
  margin-bottom: 16px;
  line-height: 1.35;
}

.reading-pane-meta {
  display: flex;
  align-items: center;
  gap: 12px;
}

.reading-pane-from-col {
  flex: 1;
  min-width: 0;
}

.pane-from-name {
  font-weight: var(--font-weight-semibold);
  color: var(--color-text);
  font-size: 13.5px;
}

.pane-to-name {
  font-size: 12px;
  color: var(--color-text-tertiary);
  margin-top: 1px;
}

.pane-date {
  font-size: 12px;
  color: var(--color-text-tertiary);
  white-space: nowrap;
}

.reading-pane-body {
  font-size: 14px;
  line-height: 1.65;
  color: var(--color-text);
}

.email-plain-text {
  font-family: inherit;
  font-size: 14px;
  line-height: 1.65;
  white-space: pre-wrap;
  word-break: break-word;
  color: var(--color-text);
}

.email-html-content {
  color: var(--color-text);
  overflow-x: auto;
}

/* Inline Message Quick Actions */
.msg-actions-inline {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}

.btn-msg-seen-quick {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  color: var(--color-text-tertiary);
  padding: 3px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.15s ease;
  opacity: 0.5;
}

.message-item:hover .btn-msg-seen-quick,
.btn-msg-seen-quick:focus {
  opacity: 1;
  background-color: var(--color-surface-hover);
  color: var(--color-text);
}

.btn-msg-seen-quick:hover {
  opacity: 1;
  background-color: var(--color-surface-active);
  color: var(--color-text);
}

/* Modern Skeleton Loader (Apps SDK UI Style) */
.reading-skeleton {
  width: 100%;
  padding: 24px 32px;
  box-sizing: border-box;
}

@keyframes appsSdkSkeletonShimmer {
  0% {
    background-position: 200% 0;
  }
  100% {
    background-position: -200% 0;
  }
}

.skeleton-line {
  border-radius: var(--radius-sm);
  background: linear-gradient(90deg, var(--gray-100) 0%, var(--gray-50) 50%, var(--gray-100) 100%);
  background-size: 200% 100%;
  animation: appsSdkSkeletonShimmer 1.5s infinite linear;
}

[data-theme="dark"] .skeleton-line {
  background: linear-gradient(90deg, var(--gray-150) 0%, var(--gray-100) 50%, var(--gray-150) 100%);
  background-size: 200% 100%;
}

.skeleton-toolbar-pulse {
  height: 28px;
  width: 200px;
  border-radius: var(--radius-sm);
  margin-bottom: 20px;
  background: linear-gradient(90deg, var(--gray-100) 0%, var(--gray-50) 50%, var(--gray-100) 100%);
  background-size: 200% 100%;
  animation: appsSdkSkeletonShimmer 1.5s infinite linear;
}

[data-theme="dark"] .skeleton-toolbar-pulse {
  background: linear-gradient(90deg, var(--gray-150) 0%, var(--gray-100) 50%, var(--gray-150) 100%);
  background-size: 200% 100%;
}

.skeleton-title {
  height: 20px;
  width: 60%;
  margin-bottom: 18px;
}

.skeleton-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 24px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--color-border-subtle);
}

.skeleton-avatar {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  flex-shrink: 0;
  background: linear-gradient(90deg, var(--gray-100) 0%, var(--gray-50) 50%, var(--gray-100) 100%);
  background-size: 200% 100%;
  animation: appsSdkSkeletonShimmer 1.5s infinite linear;
}

[data-theme="dark"] .skeleton-avatar {
  background: linear-gradient(90deg, var(--gray-150) 0%, var(--gray-100) 50%, var(--gray-150) 100%);
  background-size: 200% 100%;
}

.skeleton-meta-lines {
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex: 1;
}

.skeleton-name {
  height: 12px;
  width: 130px;
}

.skeleton-date {
  height: 10px;
  width: 80px;
}

.skeleton-body {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.skeleton-body .skeleton-line {
  height: 13px;
}

.skeleton-body .w-100 { width: 100%; }
.skeleton-body .w-95 { width: 95%; }
.skeleton-body .w-90 { width: 90%; }
.skeleton-body .w-80 { width: 80%; }
.skeleton-body .w-60 { width: 60%; }
.skeleton-body .w-40 { width: 40%; }

/* Dynamic Empty State */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

.dynamic-empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 56px 24px;
  text-align: center;
  margin: auto;
  animation: fadeIn 0.2s ease;
}

.empty-icon-wrap {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background-color: var(--color-surface-hover);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  color: var(--color-text-tertiary);
}

/* Pagination Bar */
.inbox-pagination-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 16px;
  border-top: 1px solid var(--color-border-subtle);
  background-color: var(--color-surface);
  font-size: 12px;
  color: var(--color-text-secondary);
  flex-shrink: 0;
  margin-top: auto;
  z-index: 10;
}

.pagination-info strong {
  color: var(--color-text);
  font-weight: var(--font-weight-semibold);
}

.pagination-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

.pagination-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background-color: var(--color-surface);
  color: var(--color-text);
  text-decoration: none;
  font-size: 12px;
  font-weight: 500;
  transition: all 0.15s ease;
  cursor: pointer;
}

.pagination-btn:hover:not(.disabled) {
  background-color: var(--color-surface-hover);
  border-color: var(--color-border-strong);
}

.pagination-btn.disabled {
  opacity: 0.35;
  cursor: not-allowed;
  pointer-events: none;
}

.pagination-page-indicator {
  font-size: 11.5px;
  color: var(--color-text-tertiary);
  padding: 0 4px;
}

/* Search Active Tag */
.search-active-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  background-color: var(--color-surface-active);
  color: var(--color-text);
  font-size: 11px;
  font-weight: 500;
}

.search-tag-clear {
  color: var(--color-text-tertiary);
  text-decoration: none;
  font-size: 14px;
  line-height: 1;
  font-weight: bold;
  cursor: pointer;
}

.search-tag-clear:hover {
  color: var(--color-text);
}

/* Top Progress Bar (Navigation & Pagination Loading) */
#topProgressBar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: var(--color-primary-bg, #0d0d0d);
  z-index: 99999;
  width: 0%;
  opacity: 0;
  transition: width 0.2s ease, opacity 0.15s ease;
  pointer-events: none;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.25);
}

[data-theme="dark"] #topProgressBar {
  background: #ffffff;
  box-shadow: 0 0 10px rgba(255, 255, 255, 0.4);
}

/* List Loading Skeleton (Folder & Pagination Switching) */
.list-loading-indicator {
  display: flex;
  flex-direction: column;
  padding: 8px 12px;
  gap: 12px;
}

.list-skeleton-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border-subtle);
  background-color: var(--color-surface);
}

/* Refresh Button */
.btn-refresh-inbox {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.15s ease;
}

.btn-refresh-inbox.spinning svg {
  animation: spinRefresh 0.8s linear infinite;
}

@keyframes spinRefresh {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* Move to Folder Dropdown */
.dropdown-move-wrap {
  position: relative;
  display: inline-block;
}

.dropdown-move-menu {
  position: absolute;
  top: calc(100% + 6px);
  left: 0;
  min-width: 180px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  padding: 6px 0;
  z-index: 1000;
  animation: fadeIn 0.15s ease;
}

.dropdown-move-title {
  font-size: 11px;
  font-weight: 600;
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  padding: 6px 12px 4px 12px;
}

.dropdown-move-subtitle {
  font-size: 10.5px;
  font-weight: 600;
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  padding: 6px 12px 2px 12px;
}

.dropdown-move-item {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding: 8px 12px;
  border: none;
  background: transparent;
  color: var(--color-text);
  font-size: 13px;
  text-align: left;
  cursor: pointer;
  transition: background-color 0.15s ease;
}

.dropdown-move-item:hover {
  background-color: var(--color-surface-hover);
}

.dropdown-divider {
  height: 1px;
  background-color: var(--color-border-subtle);
  margin: 4px 0;
}

/* Custom Folders in Sidebar */
.sidebar-section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 12px;
  margin-top: 20px;
  margin-bottom: 6px;
}

.sidebar-section-header .sidebar-section-title {
  padding: 0;
  margin-bottom: 0;
}

.btn-sidebar-add-folder {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background-color: var(--color-surface);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all 0.15s ease;
  padding: 0;
}

.btn-sidebar-add-folder:hover {
  background-color: var(--color-surface-hover);
  color: var(--color-text);
  border-color: var(--color-border-focus);
}

.custom-folders-nav {
  margin-bottom: 8px;
}

.custom-folder-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-radius: var(--radius-md);
  margin-bottom: 2px;
  transition: background-color 0.15s ease;
}

.custom-folder-row:hover {
  background-color: var(--color-surface-hover);
}

.custom-folder-row.active {
  background-color: var(--color-surface-active);
}

.custom-folder-link {
  flex: 1;
  min-width: 0;
  text-decoration: none;
}

.custom-folder-name {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.btn-delete-folder {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  border-radius: var(--radius-sm);
  border: none;
  background: transparent;
  color: var(--color-text-tertiary);
  cursor: pointer;
  opacity: 0;
  transition: all 0.15s ease;
  margin-right: 6px;
  padding: 0;
}

.custom-folder-row:hover .btn-delete-folder,
.btn-delete-folder:focus {
  opacity: 0.7;
}

.btn-delete-folder:hover {
  opacity: 1;
  color: #ef4444;
  background-color: rgba(239, 68, 68, 0.1);
}

.custom-folder-empty {
  padding: 6px 12px;
  font-size: 12px;
  color: var(--color-text-tertiary);
}

.sidebar-add-folder-action {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding: 8px 12px;
  font-size: 13px;
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  background: transparent;
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  margin-top: 6px;
  transition: all 0.15s ease;
  text-align: left;
}

.sidebar-add-folder-action:hover {
  background-color: var(--color-surface-hover);
  color: var(--color-text);
  border-color: var(--color-border-focus);
}

/* Modal Dialog */
.modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 99999;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  animation: modalFadeIn 0.15s ease;
}

@keyframes modalFadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.modal-dialog {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.25), 0 10px 10px -5px rgba(0, 0, 0, 0.15);
  width: 100%;
  max-width: 440px;
  overflow: hidden;
  animation: modalPop 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  color: var(--color-text);
}

@keyframes modalPop {
  from { transform: scale(0.95); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--color-border-subtle);
}

.modal-header-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.modal-header-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-md);
  background-color: var(--color-surface-hover);
  color: var(--color-text);
}

.modal-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  margin: 0;
}

.modal-close-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: transparent;
  border: none;
  color: var(--color-text-tertiary);
  cursor: pointer;
  border-radius: var(--radius-md);
  transition: all 0.15s ease;
  padding: 0;
}

.modal-close-btn:hover {
  background-color: var(--color-surface-hover);
  color: var(--color-text);
}

.modal-body {
  padding: 20px;
}

.modal-body .form-group {
  margin-bottom: 0;
}

.modal-hint {
  margin-top: 8px;
  font-size: 12.5px;
  color: var(--color-text-tertiary);
  line-height: 1.4;
  margin-bottom: 0;
}

.modal-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
  padding: 14px 20px;
  background-color: var(--color-surface-subtle);
  border-top: 1px solid var(--color-border-subtle);
  margin: 0;
}

/* WYSIWYG Editor Styles (/compose) */
.compose-card-premium {
  padding: 28px 32px;
}

.editor-wrapper {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-surface);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.editor-wrapper:focus-within {
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 1px var(--color-border-focus);
}

.editor-toolbar {
  background-color: var(--color-surface-subtle);
  border-bottom: 1px solid var(--color-border);
  padding: 6px 10px;
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
}

.toolbar-group {
  display: flex;
  align-items: center;
  gap: 2px;
}

.toolbar-divider {
  width: 1px;
  height: 16px;
  background-color: var(--color-border);
  margin: 0 4px;
}

.toolbar-btn {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-xs);
  color: var(--color-text);
  cursor: pointer;
  font-size: 13px;
  transition: background-color 0.12s ease;
}

.toolbar-btn:hover {
  background-color: var(--color-surface-hover);
}

.toolbar-btn:active {
  background-color: var(--color-surface-active);
}

.toolbar-select {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xs);
  font-size: 12px;
  padding: 3px 6px;
  color: var(--color-text);
  outline: none;
}

.rich-editor-canvas {
  min-height: 260px;
  padding: 16px;
  outline: none;
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-text);
  overflow-y: auto;
}

.rich-editor-canvas:empty::before {
  content: attr(placeholder);
  color: var(--color-text-tertiary);
  pointer-events: none;
}

.compose-footer-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 24px;
  padding-top: 16px;
  border-top: 1px solid var(--color-border-subtle);
}

.draft-status-indicator {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--color-text-tertiary);
}

.draft-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--gray-400);
}

.draft-status-indicator.has-changes .draft-dot {
  background-color: var(--gray-800);
}

.compose-actions-bar {
  display: flex;
  gap: 10px;
  align-items: center;
}

/* Toast Notification Styles */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 2000;
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-width: 380px;
  pointer-events: none;
}

.toast-item {
  pointer-events: auto;
  display: flex;
  align-items: center;
  gap: 12px;
  background-color: var(--color-surface-elevated);
  color: var(--color-text);
  padding: 12px 16px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  font-size: 13px;
  font-weight: var(--font-weight-medium);
  transform: translateY(20px);
  opacity: 0;
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.25s ease;
  border: 1px solid var(--color-border);
}

.toast-item.toast-show {
  transform: translateY(0);
  opacity: 1;
}

.toast-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text);
  flex-shrink: 0;
}

.toast-message {
  flex: 1;
  line-height: 1.4;
}

.toast-close {
  background: transparent;
  border: none;
  color: var(--color-text-tertiary);
  cursor: pointer;
  padding: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-xs);
}

.toast-close:hover {
  color: var(--color-text);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-weight: var(--font-weight-medium);
  font-size: 14px;
  padding: 8px 16px;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.15s ease;
  line-height: 1.4;
}

.btn-primary {
  background-color: var(--color-primary-bg);
  color: var(--color-primary-text);
  border-color: var(--color-primary-bg);
  box-shadow: var(--shadow-xs);
}

.btn-primary:hover {
  background-color: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  color: var(--color-primary-text);
}

.btn-secondary {
  background-color: var(--color-btn-sec-bg);
  color: var(--color-btn-sec-text);
  border-color: var(--color-btn-sec-border);
}

.btn-secondary:hover {
  background-color: var(--color-btn-sec-hover);
  border-color: var(--color-border-strong);
  color: var(--color-btn-sec-text);
}

/* Form inputs */
.form-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: 28px;
  box-shadow: var(--shadow-xs);
}

.form-group {
  margin-bottom: 18px;
}

.form-group label {
  display: block;
  font-size: 13px;
  font-weight: var(--font-weight-medium);
  color: var(--color-text);
  margin-bottom: 6px;
}

.form-control {
  width: 100%;
  padding: 9px 12px;
  font-size: 14px;
  color: var(--color-text);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
  outline: none;
}

.form-control:focus {
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 1px var(--color-border-focus);
}

.form-control::placeholder {
  color: var(--color-text-tertiary);
}

.content-container {
  padding: 24px 32px;
  max-width: 1200px;
  width: 100%;
  overflow-y: auto;
}

/* Reader Card (Standalone /message/:uid) */
.reader-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-xs);
}

.reader-header {
  padding: 24px 28px;
  border-bottom: 1px solid var(--color-border-subtle);
}

.reader-subject {
  font-size: 20px;
  font-weight: var(--font-weight-bold);
  color: var(--color-text);
  margin-bottom: 16px;
  line-height: 1.35;
}

.sender-info-box {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.sender-profile {
  display: flex;
  align-items: center;
  gap: 12px;
}

.sender-details .from-name {
  font-weight: var(--font-weight-semibold);
  color: var(--color-text);
  font-size: 13.5px;
}

.sender-details .to-address {
  font-size: 12px;
  color: var(--color-text-tertiary);
  margin-top: 2px;
}

.reader-body {
  padding: 28px;
  color: var(--color-text);
  font-size: 14px;
  line-height: 1.6;
}

.reader-action-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Alerts */
.alert-error {
  background-color: var(--color-surface-subtle);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  padding: 12px 16px;
  border-radius: var(--radius-md);
  font-size: 13px;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Auth Page */
.auth-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-bg-base);
  padding: 20px;
  position: relative;
  transition: background-color 0.2s ease;
}

.auth-card {
  width: 100%;
  max-width: 400px;
  background-color: var(--color-surface);
  padding: 36px 30px;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  text-align: left;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.auth-brand {
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  margin-bottom: 24px;
  width: 100%;
}

.auth-brand img {
  height: 38px;
  width: auto;
  max-width: 240px;
  margin: 0 auto !important;
  object-fit: contain;
}

.auth-title {
  font-size: 20px;
  font-weight: var(--font-weight-bold);
  color: var(--color-text);
  margin-bottom: 6px;
  text-align: center;
}

.auth-subtitle {
  font-size: 13px;
  color: var(--color-text-secondary);
  text-align: center;
  margin-bottom: 24px;
}

.auth-footer {
  text-align: center;
  font-size: 12px;
  color: var(--color-text-tertiary);
  margin-top: 24px;
  padding-top: 16px;
  border-top: 1px solid var(--color-border-subtle);
}

/* Settings Appearance Theme Picker */
.theme-options-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
  margin-top: 12px;
}

.theme-select-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 16px;
  background-color: var(--color-surface);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all 0.15s ease;
  color: var(--color-text);
  text-align: center;
}

.theme-select-card:hover {
  border-color: var(--color-border-strong);
  background-color: var(--color-surface-hover);
}

.theme-select-card.active {
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 1px var(--color-border-focus);
}

.theme-preview-box {
  width: 100%;
  height: 64px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.preview-light {
  background-color: #ffffff;
}
.preview-light .preview-bar {
  height: 18px;
  background-color: #f4f4f5;
  border-bottom: 1px solid #e4e4e7;
}
.preview-light .preview-content {
  flex: 1;
  background-color: #ffffff;
}

.preview-dark {
  background-color: #09090b;
}
.preview-dark .preview-bar {
  height: 18px;
  background-color: #18181b;
  border-bottom: 1px solid #27272a;
}
.preview-dark .preview-content {
  flex: 1;
  background-color: #09090b;
}

.preview-auto {
  background: linear-gradient(135deg, #ffffff 50%, #09090b 50%);
}
.preview-auto .preview-bar {
  height: 18px;
  background: linear-gradient(135deg, #f4f4f5 50%, #18181b 50%);
}
.preview-auto .preview-content {
  flex: 1;
}

.theme-select-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13.5px;
  font-weight: var(--font-weight-medium);
}

.mobile-bottom-nav {
  display: none;
}

/* ==========================================================================
   MOBILE FIRST BREAKPOINTS (<= 768px)
   ========================================================================== */
@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    height: 100%;
    height: 100dvh;
    width: 280px;
    max-width: 85vw;
    background: var(--color-surface);
    z-index: 1000;
    transform: translateX(-100%);
    transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow: 4px 0 24px rgba(0, 0, 0, 0.12);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    padding-bottom: max(40px, env(safe-area-inset-bottom, 40px));
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .sidebar-close-btn {
    display: flex;
  }

  .sidebar-backdrop {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.45);
    backdrop-filter: blur(2px);
    z-index: 999;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease;
  }

  .sidebar-backdrop.open {
    opacity: 1;
    pointer-events: auto;
  }

  .mobile-nav-toggle {
    display: flex;
  }

  .top-header {
    height: auto;
    min-height: 54px;
    padding: 10px 14px;
    gap: 8px;
    flex-wrap: wrap;
  }

  .header-title {
    font-size: 16px;
  }

  .search-box {
    order: 3;
    max-width: 100%;
    margin-top: 2px;
  }

  .btn-text-desktop {
    display: none;
  }

  .view-perspective-switch {
    display: none;
  }

  .outlook-container {
    height: calc(100vh - 150px);
  }

  .outlook-container.view-split .outlook-list-pane {
    width: 100%;
  }

  .outlook-container.view-split .outlook-reading-pane {
    display: none;
  }

  .content-container {
    padding: 14px 12px 84px 12px;
  }

  .mobile-bottom-nav {
    display: flex;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: 56px;
    background: var(--color-surface);
    border-top: 1px solid var(--color-border-subtle);
    z-index: 900;
    align-items: center;
    justify-content: space-around;
    padding-bottom: env(safe-area-inset-bottom, 0);
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.04);
  }

  .bottom-nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    flex: 1;
    height: 100%;
    color: var(--color-text-tertiary);
    font-size: 10px;
    font-weight: 500;
    text-decoration: none;
    border: none;
    background: transparent;
    cursor: pointer;
    gap: 3px;
  }

  .bottom-nav-item.active {
    color: var(--color-text);
    font-weight: 600;
  }

  .compose-circle {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--color-primary-bg);
    color: var(--color-primary-text);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    margin-top: -8px;
  }

  .toast-container {
    bottom: 70px;
    right: 14px;
    left: 14px;
    max-width: none;
  }

  .compose-footer-row {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
  }

  .compose-actions-bar {
    flex-direction: column;
  }

  .compose-send-btn {
    width: 100%;
    padding: 12px;
  }
}

/* ==========================================================================
   File Attachments & Downloads Styling
   ========================================================================== */
.compose-attachments-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 12px 14px;
  background-color: var(--color-surface-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-top: 12px;
}

.compose-attachments-summary {
  display: flex;
  align-items: center;
  font-size: 12px;
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
}

.compose-chips-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.compose-attachment-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  padding: 4px 8px 4px 10px;
  border-radius: var(--radius-full);
  font-size: 12.5px;
  color: var(--color-text);
  box-shadow: var(--shadow-xs);
  max-width: 280px;
}

.compose-attachment-chip .chip-name {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 150px;
  font-weight: var(--font-weight-medium);
}

.compose-attachment-chip .chip-size {
  color: var(--color-text-tertiary);
  font-size: 11px;
}

.compose-attachment-chip .chip-remove-btn {
  background: transparent;
  border: none;
  color: var(--color-text-tertiary);
  font-size: 16px;
  cursor: pointer;
  line-height: 1;
  padding: 0 2px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: color 0.15s ease, background-color 0.15s ease;
}

.compose-attachment-chip .chip-remove-btn:hover {
  color: #ef4444;
  background-color: rgba(239, 68, 68, 0.1);
}

/* Reading Pane & Message Reader Attachments */
.reading-pane-attachments,
.message-attachments-container {
  padding: 12px 20px;
  background-color: var(--color-surface-subtle);
  border-bottom: 1px solid var(--color-border);
}

.attachments-header {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-secondary);
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.attachments-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.attachment-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  text-decoration: none;
  color: var(--color-text);
  font-size: 13px;
  font-weight: var(--font-weight-medium);
  transition: all 0.15s ease;
  box-shadow: var(--shadow-xs);
  cursor: pointer;
}

.attachment-chip:hover {
  border-color: var(--color-primary-bg);
  background-color: var(--color-surface-subtle);
  color: var(--color-primary-bg);
  transform: translateY(-1px);
}

.att-chip-name {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 220px;
}

.att-chip-size {
  color: var(--color-text-tertiary);
  font-size: 11.5px;
  font-weight: normal;
}

.att-chip-dl-icon {
  color: var(--color-text-tertiary);
  transition: transform 0.15s ease;
}

.attachment-chip:hover .att-chip-dl-icon {
  color: var(--color-primary-bg);
  transform: translateY(1px);
}

/* Admin Table Enhancements */
.status-badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: var(--font-weight-semibold);
}

.status-badge.status-active {
  background-color: rgba(16, 185, 129, 0.12);
  color: #059669;
}

.status-badge.status-suspended {
  background-color: rgba(239, 68, 68, 0.12);
  color: #dc2626;
}

.btn-admin-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 4px 8px;
  font-size: 11.5px;
  font-weight: var(--font-weight-medium);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  cursor: pointer;
  margin-left: 4px;
  text-decoration: none;
  transition: all 0.15s ease;
}

.btn-admin-action:hover {
  background: var(--color-surface-subtle);
  color: var(--color-text);
  border-color: var(--color-border-strong);
}

.btn-admin-action.btn-admin-suspend {
  color: #d97706;
}

.btn-admin-action.btn-admin-suspend:hover {
  background: rgba(217, 119, 6, 0.1);
  border-color: #d97706;
}

.btn-admin-action.btn-admin-activate {
  color: #059669;
}

.btn-admin-action.btn-admin-activate:hover {
  background: rgba(16, 185, 129, 0.1);
  border-color: #059669;
}

.btn-admin-action.btn-admin-danger {
  color: #dc2626;
}

.btn-admin-action.btn-admin-danger:hover {
  background: rgba(220, 38, 38, 0.1);
  border-color: #dc2626;
}

/* ==========================================================================
   Sender Name & Password Multi-Step Onboarding Modal
   ========================================================================== */
.sender-name-modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 999999;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  animation: modalFadeIn 0.22s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalFadeIn {
  from { opacity: 0; transform: scale(0.97); }
  to { opacity: 1; transform: scale(1); }
}

.sender-name-modal-dialog {
  background: var(--color-surface-elevated) !important;
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: 0 20px 45px -10px rgba(0, 0, 0, 0.25), 0 0 0 1px var(--color-border);
  max-width: 480px;
  width: 100%;
  padding: 32px 28px;
  text-align: left;
  position: relative;
}

.sender-name-modal-header {
  text-align: center;
  margin-bottom: 22px;
}

.modal-badge-icon {
  width: 52px;
  height: 52px;
  background: var(--color-surface-subtle);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}

.modal-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
  line-height: 1.3;
}

.modal-subtitle {
  font-size: 13.5px;
  color: var(--color-text-secondary);
  line-height: 1.5;
  margin: 0;
}

.modal-input-large {
  font-size: 15px;
  padding: 11px 14px;
  height: auto;
  background: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
}

.modal-input-large:focus {
  border-color: var(--color-border-focus);
  outline: none;
  box-shadow: 0 0 0 2px var(--color-border-subtle);
}

.modal-preview-box {
  background: var(--color-surface-subtle);
  border: 1px dashed var(--color-border-strong);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  margin-bottom: 22px;
}

.modal-preview-box .preview-label {
  display: block;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
  color: var(--color-text-tertiary);
  margin-bottom: 6px;
}

.modal-preview-box .preview-email-tag {
  font-size: 13.5px;
  color: var(--color-text);
  font-family: var(--font-mono);
  font-weight: 600;
  word-break: break-all;
}

.modal-preview-box .preview-email-bracket {
  color: var(--color-text-secondary);
  font-weight: normal;
  margin-left: 4px;
}

.modal-actions-row {
  display: flex;
  gap: 12px;
}

.btn-large-block {
  width: 100%;
  padding: 12px 18px;
  font-size: 14.5px;
  font-weight: 600;
  justify-content: center;
  min-height: 48px;
  border-radius: var(--radius-md);
}

/* Multi-Step Onboarding Styles */
.modal-steps-indicator {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-bottom: 20px;
}

.modal-step-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: 9999px;
  font-size: 12px;
  font-weight: 600;
  background: var(--color-surface-subtle);
  color: var(--color-text-tertiary);
  border: 1px solid var(--color-border);
  transition: all 0.2s ease;
}

.modal-step-pill.active {
  background: var(--color-primary-bg);
  color: var(--color-primary-text);
  border-color: var(--color-primary-bg);
}

.modal-step-pill.completed {
  background: rgba(16, 185, 129, 0.12);
  color: #10b981;
  border-color: rgba(16, 185, 129, 0.3);
}

.modal-step-pane {
  display: none;
  animation: stepFadeIn 0.22s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-step-pane.active {
  display: block;
}

@keyframes stepFadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.password-field-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.password-field-wrapper input {
  padding-right: 42px;
}

.password-toggle-btn {
  position: absolute;
  right: 10px;
  background: transparent;
  border: none;
  color: var(--color-text-tertiary);
  cursor: pointer;
  padding: 6px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.15s;
}

.password-toggle-btn:hover {
  color: var(--color-text);
}

.password-strength-container {
  margin-top: 8px;
  margin-bottom: 14px;
}

.password-strength-bar {
  display: flex;
  gap: 4px;
  height: 4px;
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 5px;
}

.strength-segment {
  flex: 1;
  height: 100%;
  background: var(--color-border);
  border-radius: 2px;
  transition: background-color 0.25s ease;
}

.strength-label {
  font-size: 11.5px;
  color: var(--color-text-secondary);
}

.modal-btn-secondary {
  background: var(--color-btn-sec-bg);
  border: 1px solid var(--color-btn-sec-border);
  color: var(--color-btn-sec-text);
  padding: 12px 18px;
  font-size: 14.5px;
  font-weight: 500;
  border-radius: var(--radius-md);
  cursor: pointer;
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: all 0.15s ease;
}

.modal-btn-secondary:hover {
  background: var(--color-btn-sec-hover);
  border-color: var(--color-border-strong);
}

/* Mobile-First Optimizations */
@media (max-width: 640px) {
  .sender-name-modal-backdrop {
    padding: 12px;
    align-items: flex-end; /* Bottom sheet on mobile */
  }

  .sender-name-modal-dialog {
    padding: 24px 20px 20px;
    border-radius: 20px 20px 0 0;
    max-width: 100%;
    margin: 0;
    max-height: 90vh;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }

  .modal-title {
    font-size: 18px;
  }

  .modal-subtitle {
    font-size: 13px;
  }

  .modal-input-large {
    font-size: 16px !important; /* Prevents auto-zoom on iOS */
    padding: 13px 14px;
  }

  .modal-actions-row {
    flex-direction: column-reverse;
    gap: 10px;
  }

  .modal-btn-secondary,
  .btn-large-block {
    width: 100%;
    min-height: 50px;
  }
}

/* ==========================================================================
   Mobile-First Batch Selection & Action Bar
   ========================================================================== */
.btn-select-mode-toggle {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  cursor: pointer;
  padding: 6px 12px;
  font-size: 13px;
  font-weight: 500;
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text-secondary);
  transition: all 0.15s ease;
}

.btn-select-mode-toggle:hover {
  background: var(--color-surface-hover);
  color: var(--color-text);
}

.btn-select-mode-toggle.active {
  background: var(--color-primary-bg) !important;
  color: var(--color-primary-text) !important;
  border-color: var(--color-primary-bg) !important;
}

.msg-select-check {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  cursor: pointer;
  flex-shrink: 0;
  margin-right: -2px;
  border-radius: 4px;
}

.batch-select-input {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
  pointer-events: none;
}

.batch-checkbox-custom {
  width: 18px;
  height: 18px;
  border-radius: 4px;
  border: 1.5px solid var(--color-border-strong);
  background: var(--color-surface);
  display: flex;
  align-items: center;
  justify-content: center;
  color: transparent;
  transition: all 0.15s ease;
}

.batch-select-input:checked + .batch-checkbox-custom {
  background: var(--color-primary-bg);
  border-color: var(--color-primary-bg);
  color: var(--color-primary-text);
}

.messages-list li.selected .message-item {
  background-color: var(--color-surface-hover) !important;
}

.messages-list li.sliding-out {
  opacity: 0;
  transform: translateX(-24px);
  transition: all 0.22s cubic-bezier(0.16, 1, 0.3, 1);
  max-height: 0;
  overflow: hidden;
  padding-top: 0;
  padding-bottom: 0;
  border-bottom: none;
}

/* Floating Batch Action Bar */
.batch-action-bar {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 9999;
  background: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  box-shadow: 0 16px 36px -4px rgba(0, 0, 0, 0.25), 0 0 0 1px var(--color-border);
  border-radius: var(--radius-xl);
  padding: 8px 16px;
  min-width: 320px;
  max-width: 92vw;
  animation: batchBarPop 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes batchBarPop {
  from { opacity: 0; transform: translate(-50%, 14px) scale(0.96); }
  to { opacity: 1; transform: translate(-50%, 0) scale(1); }
}

.batch-bar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.batch-bar-left {
  display: flex;
  align-items: center;
  gap: 8px;
}

.batch-select-all-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--color-text);
  user-select: none;
}

.batch-bar-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

.batch-action-btn {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  color: var(--color-text);
  border-radius: var(--radius-md);
  padding: 7px 12px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.12s ease;
  min-height: 36px;
}

.batch-action-btn:hover {
  background: var(--color-surface-hover);
  border-color: var(--color-border-strong);
}

.batch-action-btn.batch-action-delete {
  color: #ef4444;
  border-color: rgba(239, 68, 68, 0.25);
  background: rgba(239, 68, 68, 0.06);
}

.batch-action-btn.batch-action-delete:hover {
  background: rgba(239, 68, 68, 0.14);
}

.batch-action-btn.batch-action-cancel {
  padding: 7px 9px;
  color: var(--color-text-tertiary);
}

.batch-action-btn.batch-action-cancel:hover {
  color: var(--color-text);
}

.batch-dropdown-wrap {
  position: relative;
}

.batch-move-dropdown {
  position: absolute;
  bottom: calc(100% + 8px);
  right: 0;
  background: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  box-shadow: 0 14px 28px rgba(0, 0, 0, 0.2);
  border-radius: var(--radius-lg);
  padding: 6px;
  min-width: 170px;
  display: none;
  flex-direction: column;
  gap: 2px;
  z-index: 100000;
}

.batch-move-dropdown.show {
  display: flex;
}

.batch-dropdown-header {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
  color: var(--color-text-tertiary);
  padding: 6px 10px 4px;
}

.batch-folder-item {
  background: transparent;
  border: none;
  text-align: left;
  padding: 8px 10px;
  font-size: 13px;
  color: var(--color-text);
  border-radius: var(--radius-md);
  cursor: pointer;
  width: 100%;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: background-color 0.1s;
}

.batch-folder-item:hover {
  background-color: var(--color-surface-hover);
}

.batch-dropdown-divider {
  height: 1px;
  background-color: var(--color-border-subtle);
  margin: 4px 0;
}

@media (max-width: 640px) {
  .batch-action-bar {
    left: 10px;
    right: 10px;
    bottom: 14px;
    transform: none;
    min-width: unset;
    max-width: unset;
    padding: 10px 12px;
    border-radius: 16px;
  }

  .batch-bar-inner {
    gap: 8px;
  }

  .batch-action-btn {
    padding: 8px 10px;
    font-size: 12.5px;
    min-height: 42px;
  }

  .batch-action-btn .batch-btn-label {
    display: none; /* Icon only on mobile */
  }

  .msg-select-check {
    width: 32px;
    height: 32px;
  }

  .batch-checkbox-custom {
    width: 20px;
    height: 20px;
  }
}