@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Noto+Sans+TC:wght@300;400;500;700&family=Noto+Serif+TC:wght@400;700&family=ZCOOL+XiaoWei&display=swap');

:root {
  /* Premium Jade & Warm Paper Color Palette */
  --primary-hue: 165;
  --primary: hsl(var(--primary-hue), 76%, 17%); /* deep jade ink #0C5A47 */
  --primary-light: hsl(var(--primary-hue), 55%, 32%);
  --primary-dark: hsl(var(--primary-hue), 90%, 10%);
  --primary-glow: hsla(var(--primary-hue), 76%, 17%, 0.08);
  
  --secondary-hue: 38;
  --secondary: hsl(var(--secondary-hue), 95%, 44%); /* Gold Amber #D97706 */
  --secondary-light: hsl(var(--secondary-hue), 85%, 52%);
  --secondary-dark: hsl(var(--secondary-hue), 90%, 35%);
  --secondary-glow: hsla(var(--secondary-hue), 95%, 44%, 0.06);
  
  --coral-hue: 5;
  --coral: hsl(var(--coral-hue), 75%, 55%); /* coral red */
  --coral-light: hsl(var(--coral-hue), 85%, 65%);
  --coral-glow: hsla(var(--coral-hue), 75%, 55%, 0.1);
  
  --bg-app: hsl(45, 20%, 96%); /* Warm Paper #FAF9F5 */
  --bg-card: hsl(0, 0%, 100%);
  --bg-sidebar: hsl(165, 80%, 8%); /* Very dark jade/black */
  
  --text-main: hsl(165, 30%, 8%); /* Dark Ink #0C1613 */
  --text-muted: hsl(165, 10%, 42%);
  --text-on-primary: hsl(0, 0%, 100%);
  --text-on-sidebar: hsl(165, 20%, 80%);
  
  --border-color: hsl(45, 15%, 88%);
  --border-focus: var(--primary-light);
  
  --card-shadow: 0 10px 40px rgba(12, 22, 19, 0.03), 0 2px 10px rgba(12, 22, 19, 0.01);
  --sidebar-shadow: 6px 0 40px rgba(6, 20, 16, 0.06);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 28px;
  
  --font-sans: 'Inter', 'Noto Sans TC', sans-serif;
  --font-chinese-sans: 'Noto Sans TC', sans-serif;
  --font-chinese-serif: 'Noto Serif TC', serif;
  --font-serif: 'ZCOOL XiaoWei', serif;
  
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Theme Overrides */
.dark-theme {
  --bg-app: hsl(165, 15%, 8%);
  --bg-card: hsl(165, 12%, 12%);
  --bg-sidebar: hsl(165, 18%, 6%);
  
  --text-main: hsl(45, 20%, 92%);
  --text-muted: hsl(165, 8%, 62%);
  --text-on-sidebar: hsl(165, 12%, 80%);
  
  --border-color: hsl(165, 10%, 20%);
  --primary: hsl(var(--primary-hue), 60%, 45%);
  --primary-light: hsl(var(--primary-hue), 50%, 55%);
  --primary-glow: hsla(var(--primary-hue), 60%, 45%, 0.18);
  
  --card-shadow: 0 15px 45px rgba(0, 0, 0, 0.35);
  --sidebar-shadow: 6px 0 45px rgba(0, 0, 0, 0.45);
}

/* Reset & Global */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-app);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  overflow: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Custom Scrollbars */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* Main layouts */
.app-container {
  display: flex;
  width: 100vw;
  height: 100vh;
  position: relative;
}

.sidebar {
  width: 290px;
  background-color: var(--bg-sidebar);
  color: var(--text-on-sidebar);
  display: flex;
  flex-direction: column;
  padding: 36px 24px;
  border-right: 1px solid rgba(255, 255, 255, 0.04);
  box-shadow: var(--sidebar-shadow);
  z-index: 10;
  flex-shrink: 0;
  transition: transform var(--transition-normal);
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 44px;
}

.brand-logo {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--primary-light), var(--primary));
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-serif);
  font-size: 26px;
  color: white;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.2);
}

.brand-name {
  font-family: var(--font-serif);
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 0.5px;
  color: white;
}

.brand-sub {
  font-size: 10px;
  color: var(--secondary-light);
  font-family: var(--font-sans);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-top: 3px;
}

.nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex-grow: 1;
}

.nav-item button {
  width: 100%;
  background: none;
  border: none;
  padding: 13px 16px;
  color: var(--text-on-sidebar);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  text-align: left;
  border-radius: 12px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 12px;
  transition: all var(--transition-fast);
}

.nav-item button:hover {
  background-color: rgba(255, 255, 255, 0.04);
  color: white;
}

.nav-item.active button {
  background-color: var(--primary-light);
  color: white;
  box-shadow: 0 4px 15px var(--primary-glow);
}

.nav-item button svg {
  width: 20px;
  height: 20px;
  opacity: 0.7;
}

.nav-item.active button svg {
  opacity: 1;
}

.user-profile-widget {
  margin-top: auto;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.user-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 38px;
  height: 38px;
  background-color: var(--secondary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: white;
}

.user-details {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.user-name {
  font-size: 13px;
  font-weight: 600;
  color: white;
}

.user-role {
  font-size: 11px;
  color: var(--text-on-sidebar);
  opacity: 0.65;
}

/* Main Workspace */
.main-content {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
  position: relative;
}

.topbar {
  height: 84px;
  border-bottom: 1px solid var(--border-color);
  background-color: var(--bg-card);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 40px;
  flex-shrink: 0;
  z-index: 5;
}

.view-title-container h1 {
  font-size: 24px;
  font-weight: 700;
  font-family: var(--font-chinese-sans);
  color: var(--primary);
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.theme-toggle-btn {
  background: none;
  border: 1px solid var(--border-color);
  width: 42px;
  height: 42px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-main);
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  background-color: var(--bg-app);
}

.streak-counter {
  display: flex;
  align-items: center;
  gap: 6px;
  background-color: hsl(20, 90%, 96%);
  border: 1px solid hsl(20, 90%, 90%);
  color: hsl(20, 85%, 45%);
  padding: 7px 15px;
  border-radius: 20px;
  font-weight: 600;
  font-size: 13px;
}

.dark-theme-active {
  background-color: hsl(20, 40%, 15%) !important;
  border-color: hsl(20, 45%, 20%) !important;
  color: hsl(20, 90%, 65%) !important;
}

/* Views Wrapper */
.views-container {
  flex-grow: 1;
  padding: 40px;
  overflow-y: auto;
  position: relative;
}

.view-section {
  display: none;
  animation: viewFadeIn 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  height: 100%;
}

.view-section.active {
  display: block;
}

@keyframes viewFadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Card Styling */
.card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  box-shadow: var(--card-shadow);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.card-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 12px;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Dashboard layouts */
.dashboard-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 32px;
}

@media (max-width: 1024px) {
  .dashboard-grid {
    grid-template-columns: 1fr;
  }
}

.dashboard-left, .dashboard-right {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.welcome-card {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
  border: none;
}

.welcome-card h2 {
  font-family: var(--font-serif);
  font-size: 32px;
  margin-bottom: 8px;
}

.welcome-card p {
  opacity: 0.88;
  font-size: 15px;
  line-height: 1.6;
}

/* Dynamic rubies CSS flex system (Fixing browser ruby limits) */
.ruby-grid-container {
  display: inline-flex;
  align-items: flex-end;
  gap: 6px;
  font-family: var(--font-chinese-serif);
}

.ruby-cell {
  display: flex;
  position: relative;
  align-items: center;
  padding-right: 12px; /* make space for right aligned Bopomofo */
}

.ruby-hanzi {
  font-size: 42px;
  line-height: 1.1;
  color: var(--text-main);
}

.ruby-zhuyin-right {
  position: absolute;
  right: -2px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  font-size: 12px;
  line-height: 1.1;
  color: var(--secondary);
  font-family: var(--font-chinese-sans);
  writing-mode: vertical-rl;
  letter-spacing: -2px;
}

/* Horizontal standard rubies (Pinyin-first) */
.pinyin-top-mark {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  text-align: center;
  display: block;
  margin-bottom: 4px;
}

/* Level Testing elements */
.test-option-btn {
  width: 100%;
  text-align: left;
  padding: 16px 20px;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 15px;
  color: var(--text-main);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 12px;
}

.test-option-btn:hover {
  background-color: var(--primary-glow);
  border-color: var(--primary-light);
  transform: translateX(4px);
}

.test-option-btn:active {
  background-color: var(--border-color);
}

/* Lexical fields styling */
.lexical-category-card {
  cursor: pointer;
  transition: all var(--transition-fast);
}

.lexical-category-card:hover {
  border-color: var(--primary);
  transform: translateY(-3px);
  box-shadow: 0 12px 30px var(--primary-glow);
}

/* Tables styling */
table th, table td {
  border-bottom: 1px solid var(--border-color);
}
table tr:hover td {
  background-color: var(--bg-app);
}

/* 5-Layer card peeling mechanics */
.flashcards-container {
  max-width: 440px;
  margin: 32px auto;
}

.flashcard-wrapper {
  width: 100%;
  min-height: 350px;
  position: relative;
  display: flex;
}

.flashcard-face {
  width: 100%;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  box-shadow: var(--card-shadow);
  transition: transform var(--transition-normal);
}

/* Arcade Games Styles */
.play-game-arena {
  width: 100%;
}

.game-card-btn {
  background-color: var(--primary-glow);
  border: 2px solid var(--primary-light);
  border-radius: var(--radius-sm);
  padding: 18px;
  font-size: 16px;
  font-weight: 700;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.game-card-btn:hover {
  background-color: var(--primary);
  color: white;
  transform: translateY(-2px);
}

/* Interactive keyboards (Bopomofo Grid inside Arcade) */
.arcade-keyboard-grid {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  gap: 8px;
  margin-top: 20px;
}

.key-btn {
  background-color: var(--bg-app);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 10px 4px;
  font-size: 14px;
  font-weight: 700;
  color: var(--text-main);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.key-btn:hover {
  background-color: var(--primary-light);
  color: white;
  border-color: var(--primary-light);
}

.key-btn:active {
  transform: scale(0.95);
}

/* Night market game clients */
.client-order-box {
  background-color: var(--bg-app);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  margin-bottom: 20px;
  text-align: center;
}

/* Settings Form elements */
.form-group {
  margin-bottom: 22px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
}

.input-field {
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background-color: var(--bg-app);
  color: var(--text-main);
  font-family: var(--font-sans);
  outline: none;
  font-size: 14px;
  transition: all var(--transition-fast);
}

.input-field:focus {
  border-color: var(--primary-light);
  box-shadow: 0 0 0 2px var(--primary-glow);
}

.btn {
  padding: 12px 24px;
  border-radius: 24px;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  color: var(--text-main);
  transition: all var(--transition-fast);
}

.btn:hover {
  background-color: var(--bg-app);
}

.btn-primary {
  background-color: var(--primary-light);
  border-color: var(--primary-light);
  color: white;
}

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

/* Modal layers */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(6, 20, 16, 0.45);
  backdrop-filter: blur(5px);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-content {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px;
  width: 480px;
  max-width: 90%;
  box-shadow: 0 30px 60px rgba(6, 20, 16, 0.18);
  animation: modalSlideUp 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalSlideUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

.info-alert {
  background-color: var(--secondary-glow);
  border: 1px solid var(--secondary-light);
  color: var(--text-main);
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  line-height: 1.5;
  margin-bottom: 20px;
}

.info-alert a {
  color: var(--secondary-dark);
  font-weight: 600;
  text-decoration: underline;
}

/* Chat bubles styling */
.lesson-layout {
  display: grid;
  grid-template-columns: 3fr 1fr;
  gap: 32px;
  height: calc(100vh - 160px);
}

@media (max-width: 1024px) {
  .lesson-layout {
    grid-template-columns: 1fr;
    height: auto;
  }
}

.chat-panel {
  display: flex;
  flex-direction: column;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--card-shadow);
  overflow: hidden;
  height: 100%;
}

.chat-header {
  padding: 18px 24px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.teacher-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.teacher-avatar {
  width: 42px;
  height: 42px;
  background: linear-gradient(135deg, var(--primary-light), var(--primary-dark));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: 16px;
}

.lesson-timer {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  color: var(--secondary-dark);
}

.chat-messages {
  flex-grow: 1;
  padding: 24px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 20px;
  background-color: var(--bg-app);
}

.message-bubble {
  max-width: 75%;
  padding: 16px 20px;
  border-radius: var(--radius-md);
  line-height: 1.6;
  font-size: 15px;
  animation: bubbleSlideUp 0.25s ease;
}

.message-bubble.teacher {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  align-self: flex-start;
  border-bottom-left-radius: 4px;
}

.message-bubble.student {
  background-color: var(--primary);
  color: white;
  align-self: flex-end;
  border-bottom-right-radius: 4px;
}

@keyframes bubbleSlideUp {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.chat-input-bar {
  padding: 18px 24px;
  border-top: 1px solid var(--border-color);
  display: flex;
  gap: 12px;
  align-items: center;
}

.chat-input {
  flex-grow: 1;
  border: 1px solid var(--border-color);
  border-radius: 24px;
  padding: 12px 20px;
  font-family: var(--font-sans);
  font-size: 15px;
  background-color: var(--bg-app);
  color: var(--text-main);
  outline: none;
  transition: border var(--transition-fast);
}

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

.btn-send {
  background-color: var(--primary-light);
  color: white;
  border: none;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background var(--transition-fast);
}

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

.hidden {
  display: none !important;
}

.spinner {
  width: 24px;
  height: 24px;
  border: 3px solid rgba(255,255,255,0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 1s infinite linear;
}

.spinner-primary {
  border-color: var(--border-color);
  border-top-color: var(--primary-light);
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loading-indicator {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 30px;
  color: var(--text-muted);
}