/* CSS Variables for theming */
:root,
[data-theme="light"] {
  --color-bg: #ffffff;
  --color-bg-secondary: #f5f5f5;
  --color-text: #1a1a1a;
  --color-text-secondary: #666666;
  --color-primary: #1a73e8;
  --color-primary-hover: #1557b0;
  --color-border: #e0e0e0;
  --color-surface: #ffffff;
  --color-nav-bg: #f8f9fa;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --transition-layout: 300ms ease;
}

[data-theme="dark"] {
  --color-bg: #1a1a1a;
  --color-bg-secondary: #2d2d2d;
  --color-text: #e0e0e0;
  --color-text-secondary: #999999;
  --color-primary: #8ab4f8;
  --color-primary-hover: #aecbfa;
  --color-border: #3d3d3d;
  --color-surface: #252525;
  --color-nav-bg: #202020;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
}

/* Reset */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  color: var(--color-text);
  background-color: var(--color-bg);
}

#app {
  height: 100%;
  display: flex;
  flex-direction: column;
}

/* App Shell Layout */
.app-shell {
  display: flex;
  flex-direction: column;
  height: 100%;
  overflow: hidden;
}

/* Desktop Layout - Dual Pane */
.layout-desktop {
  display: flex;
  flex: 1;
  overflow: hidden;
}

.layout-desktop .pane-sidebar {
  width: 320px;
  min-width: 280px;
  border-right: 1px solid var(--color-border);
  overflow-y: auto;
  background-color: var(--color-nav-bg);
}

.layout-desktop .pane-content {
  flex: 1;
  overflow-y: auto;
  background-color: var(--color-bg);
}

/* Mobile Layout - Single Pane */
.layout-mobile {
  display: flex;
  flex-direction: column;
  flex: 1;
  overflow: hidden;
}

.layout-mobile .pane-main {
  flex: 1;
  overflow-y: auto;
  background-color: var(--color-bg);
}

.layout-mobile .nav-bar {
  display: flex;
  justify-content: space-around;
  align-items: center;
  height: 56px;
  background-color: var(--color-nav-bg);
  border-top: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.layout-mobile .nav-bar .nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 4px 12px;
  border: none;
  background: none;
  color: var(--color-text-secondary);
  font-size: 12px;
  cursor: pointer;
  text-decoration: none;
  transition: color 0.15s;
}

.layout-mobile .nav-bar .nav-item.active {
  color: var(--color-primary);
}

.layout-mobile .nav-bar .nav-item:hover {
  color: var(--color-primary-hover);
}

/* Desktop sidebar navigation */
.layout-desktop .sidebar-nav {
  display: flex;
  flex-direction: column;
  padding: 8px 0;
}

.layout-desktop .sidebar-nav .nav-item {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 8px 16px;
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: background-color 0.15s, color 0.15s;
}

.layout-desktop .sidebar-nav .nav-item:hover {
  background-color: var(--color-bg-secondary);
  color: var(--color-primary-hover);
}

.layout-desktop .sidebar-nav .nav-item.active {
  color: var(--color-primary);
  background-color: var(--color-bg-secondary);
  font-weight: 500;
}

/* Route container */
.route-view {
  padding: 16px;
}

/* Responsive breakpoint */
@media (min-width: 1024px) {
  .layout-mobile {
    display: none;
  }
}

@media (max-width: 1023px) {
  .layout-desktop {
    display: none;
  }
}

/* Utility: ensure touch targets */
button, a, [role="button"] {
  min-width: 44px;
  min-height: 44px;
}

/* Placeholder view styles */
.view-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--color-text-secondary);
  font-size: 18px;
}

/* Pull-to-refresh indicator */
.pull-refresh-indicator {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 0;
  overflow: hidden;
  background-color: var(--color-bg-secondary);
  color: var(--color-text-secondary);
  font-size: 14px;
  transition: height 0.2s ease, opacity 0.2s ease;
}

/* Swipe boundary message */
.swipe-boundary-message {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  padding: 12px 24px;
  background-color: var(--color-bg-secondary);
  color: var(--color-text-secondary);
  border-radius: 8px;
  box-shadow: var(--shadow-md);
  font-size: 14px;
  z-index: 1000;
  opacity: 0;
  animation: fadeInOut 1.5s ease forwards;
}

@keyframes fadeInOut {
  0% { opacity: 0; }
  15% { opacity: 1; }
  70% { opacity: 1; }
  100% { opacity: 0; }
}

/* ==============================
   Read-Aloud Player
   Requirements: 10.3, 10.4
   ============================== */

.read-aloud-player {
  display: flex;
  align-items: center;
  padding: 8px 0;
  margin: 8px 0;
  border-top: 1px solid var(--color-border);
}

.player-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

.player-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 8px 16px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  background-color: var(--color-surface);
  color: var(--color-text);
  font-size: 14px;
  cursor: pointer;
  transition: background-color 0.15s, border-color 0.15s;
}

.player-btn:hover:not(:disabled) {
  background-color: var(--color-bg-secondary);
  border-color: var(--color-primary);
}

.player-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.player-icon {
  font-size: 16px;
}

.player-loading {
  font-size: 14px;
  color: var(--color-text-secondary);
  margin-left: 8px;
  animation: pulsate 1.2s ease-in-out infinite;
}

@keyframes pulsate {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

/* Error state */
.player-error {
  display: flex;
  align-items: center;
  gap: 12px;
}

.player-error-msg {
  font-size: 14px;
  color: #d93025;
}

[data-theme="dark"] .player-error-msg {
  color: #f28b82;
}

.player-retry {
  color: var(--color-primary);
  border-color: var(--color-primary);
}

/* Paragraph highlighting during playback (requirement 10.4) */
.read-aloud-active-paragraph {
  background-color: rgba(26, 115, 232, 0.08);
  border-left: 3px solid var(--color-primary);
  padding-left: 12px;
  border-radius: 2px;
  transition: background-color 0.3s ease, border-left-color 0.3s ease;
}

[data-theme="dark"] .read-aloud-active-paragraph {
  background-color: rgba(138, 180, 248, 0.1);
}

/* Login Gate */
.login-gate {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  padding: 24px;
}

.login-title {
  font-size: 24px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 8px;
}

.login-subtitle {
  font-size: 14px;
  color: var(--color-text-secondary);
  margin-bottom: 24px;
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 100%;
  max-width: 360px;
}

.login-input {
  padding: 12px 14px;
  min-height: 44px;
  font-size: 16px;
  color: var(--color-text);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  outline: none;
}

.login-input:focus {
  border-color: var(--color-primary);
}

.login-button {
  padding: 12px 16px;
  min-height: 44px;
  font-size: 16px;
  font-weight: 500;
  color: #ffffff;
  background-color: var(--color-primary);
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 100ms ease;
}

.login-button:hover {
  background-color: var(--color-primary-hover);
}

.login-button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.login-error {
  margin-top: 12px;
  font-size: 14px;
  color: #d93025;
  text-align: center;
}