/* 高中數學互動學習平台 - 多主題極致視覺樣式表 (含真全螢幕互動與完全自動同步) */

@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+TC:wght@300;400;500;700;900&family=Outfit:wght@300;400;600;800&family=Fira+Code:wght@400;600&display=swap');

/* 1. 主題變數系統 (Theme Variables System) */

/* 預設主題：純淨極簡白 (Minimalist Pure Light) */
:root, [data-theme="pure-light"] {
  --bg-dark: #f8fafc;
  --bg-pattern: 
    radial-gradient(circle at 10% 20%, rgba(37, 99, 235, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 90% 80%, rgba(14, 165, 233, 0.05) 0%, transparent 50%);
  --header-bg: rgba(255, 255, 255, 0.85);
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --glass-border: rgba(203, 213, 225, 0.8);
  --glass-border-hover: rgba(37, 99, 235, 0.4);
  
  --primary: #2563eb;
  --primary-gradient: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
  --primary-glow: rgba(37, 99, 235, 0.25);
  
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-dim: #64748b;
  --input-bg: #ffffff;
  --modal-bg: #ffffff;
}

/* 主題二：深色極光玻璃 (Dark Space Aurora Glass) */
[data-theme="dark-glass"] {
  --bg-dark: #070a14;
  --bg-pattern: 
    radial-gradient(circle at 15% 15%, rgba(99, 102, 241, 0.15) 0%, transparent 45%),
    radial-gradient(circle at 85% 85%, rgba(217, 70, 239, 0.12) 0%, transparent 45%),
    radial-gradient(circle at 50% 50%, rgba(6, 182, 212, 0.08) 0%, transparent 60%);
  --header-bg: rgba(7, 10, 20, 0.8);
  --bg-card: rgba(19, 26, 47, 0.65);
  --bg-card-hover: rgba(30, 41, 71, 0.85);
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-border-hover: rgba(99, 102, 241, 0.5);
  
  --primary: #6366f1;
  --primary-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #d946ef 100%);
  --primary-glow: rgba(99, 102, 241, 0.35);
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --input-bg: rgba(15, 23, 42, 0.6);
  --modal-bg: #0f172a;
}

/* 主題三：古典黑板實驗室 (Chalkboard Math Lab) */
[data-theme="chalkboard"] {
  --bg-dark: #12221b;
  --bg-pattern: 
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  --header-bg: rgba(18, 34, 27, 0.9);
  --bg-card: rgba(22, 45, 35, 0.85);
  --bg-card-hover: rgba(29, 58, 45, 0.95);
  --glass-border: rgba(253, 224, 71, 0.2);
  --glass-border-hover: rgba(253, 224, 71, 0.6);
  
  --primary: #fde047;
  --primary-gradient: linear-gradient(135deg, #fde047 0%, #eab308 100%);
  --primary-glow: rgba(253, 224, 71, 0.3);
  
  --text-main: #fef08a;
  --text-muted: #cbd5e1;
  --text-dim: #94a3b8;
  --input-bg: rgba(15, 28, 22, 0.8);
  --modal-bg: #142820;
}

/* 主題四：賽博霓虹科技 (Cyber Neon Tech) */
[data-theme="cyber-neon"] {
  --bg-dark: #030712;
  --bg-pattern: 
    radial-gradient(circle at 50% 0%, rgba(6, 182, 212, 0.25) 0%, transparent 60%),
    radial-gradient(circle at 100% 100%, rgba(236, 72, 153, 0.2) 0%, transparent 60%);
  --header-bg: rgba(3, 7, 18, 0.9);
  --bg-card: rgba(15, 23, 42, 0.85);
  --bg-card-hover: rgba(30, 41, 59, 0.95);
  --glass-border: rgba(6, 182, 212, 0.3);
  --glass-border-hover: rgba(6, 182, 212, 0.8);
  
  --primary: #06b6d4;
  --primary-gradient: linear-gradient(135deg, #06b6d4 0%, #3b82f6 50%, #ec4899 100%);
  --primary-glow: rgba(6, 182, 212, 0.45);
  
  --text-main: #22d3ee;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --input-bg: rgba(3, 7, 18, 0.9);
  --modal-bg: #0b1329;
}

/* 2. 通用基礎設定 */
:root {
  --font-main: 'Outfit', 'Noto Sans TC', -apple-system, BlinkMacSystemFont, sans-serif;
  --radius-lg: 18px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-dark);
  background-image: var(--bg-pattern);
  background-size: cover;
  background-attachment: fixed;
  color: var(--text-main);
  font-family: var(--font-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.6;
  overflow-x: hidden;
  transition: background-color 0.4s ease, color 0.4s ease;
}

/* 頂部導覽列 Header */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--header-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--glass-border);
  padding: 16px 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  transition: var(--transition);
}

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

.brand-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  box-shadow: 0 0 20px var(--primary-glow);
  object-fit: cover;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.brand-title {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.5px;
}

.brand-badge {
  font-size: 0.75rem;
  padding: 3px 8px;
  background: rgba(99, 102, 241, 0.15);
  color: var(--primary);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  font-weight: 600;
}

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

/* 雲端同步狀態燈 */
.sync-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background-color: #94a3b8;
  display: inline-block;
  transition: var(--transition);
}

.sync-dot.connected {
  background-color: #10b981;
  box-shadow: 0 0 8px #10b981;
}

.sync-dot.syncing {
  background-color: #f59e0b;
  animation: pulse 1s infinite alternate;
}

@keyframes pulse {
  0% { opacity: 0.3; }
  100% { opacity: 1; transform: scale(1.2); }
}

/* 主題風格選擇下拉選單 */
.theme-selector {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--input-bg);
  border: 1px solid var(--glass-border);
  padding: 6px 12px;
  border-radius: var(--radius-md);
  color: var(--text-main);
  font-size: 0.9rem;
  cursor: pointer;
  outline: none;
  font-family: var(--font-main);
  transition: var(--transition);
}

.theme-selector:hover {
  border-color: var(--primary);
}

.theme-selector select {
  background: transparent;
  border: none;
  color: var(--text-main);
  font-family: var(--font-main);
  font-weight: 600;
  font-size: 0.88rem;
  outline: none;
  cursor: pointer;
}

.theme-selector select option {
  background: var(--modal-bg);
  color: var(--text-main);
}

/* 按鈕樣式 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: var(--transition);
  font-family: var(--font-main);
  text-decoration: none;
}

.btn-primary {
  background: var(--primary-gradient);
  color: #ffffff;
  box-shadow: 0 4px 15px var(--primary-glow);
}

[data-theme="chalkboard"] .btn-primary {
  color: #12221b;
  font-weight: 800;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px var(--primary-glow);
  filter: brightness(1.1);
}

.btn-secondary {
  background: var(--input-bg);
  color: var(--text-main);
  border: 1px solid var(--glass-border);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--glass-border-hover);
}

.btn-danger {
  background: rgba(244, 63, 94, 0.15);
  color: #f43f5e;
  border: 1px solid rgba(244, 63, 94, 0.3);
}

.btn-danger:hover {
  background: rgba(244, 63, 94, 0.3);
  box-shadow: 0 4px 15px rgba(244, 63, 94, 0.3);
}

.btn-icon-only {
  padding: 8px 12px;
  font-size: 1.1rem;
}

/* PWA 安裝提示列 */
.pwa-banner {
  background: var(--primary-gradient);
  opacity: 0.9;
  color: #ffffff;
  padding: 10px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.9rem;
  box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

/* 主內容區域 Layout */
main {
  max-width: 1320px;
  margin: 0 auto;
  padding: 32px 24px;
  width: 100%;
  flex: 1;
}

/* 分類與控制工具列 Section */
.controls-section {
  margin-bottom: 32px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* 冊別選單標籤頁 Tabs */
.volume-tabs {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 8px;
  scrollbar-width: thin;
}

.volume-tab {
  padding: 10px 20px;
  border-radius: 30px;
  background: var(--input-bg);
  border: 1px solid var(--glass-border);
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  white-space: nowrap;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 6px;
}

.volume-tab:hover {
  background: var(--bg-card-hover);
  color: var(--text-main);
  border-color: var(--glass-border-hover);
}

.volume-tab.active {
  background: var(--primary-gradient);
  color: #ffffff;
  border-color: transparent;
  box-shadow: 0 4px 20px var(--primary-glow);
}

[data-theme="chalkboard"] .volume-tab.active {
  color: #12221b;
  font-weight: 800;
}

.volume-tab .badge-count {
  font-size: 0.75rem;
  background: rgba(0, 0, 0, 0.25);
  padding: 2px 7px;
  border-radius: 12px;
  color: inherit;
}

/* 搜尋與過濾 Bar */
.filter-bar {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
}

.search-box {
  position: relative;
  flex: 1;
  min-width: 260px;
}

.search-box input {
  width: 100%;
  padding: 12px 16px 12px 42px;
  background: var(--input-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-main);
  font-size: 0.95rem;
  font-family: var(--font-main);
  outline: none;
  transition: var(--transition);
}

.search-box input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

.search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-dim);
  font-size: 1.1rem;
}

.stats-info {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* 網頁卡片網格 Grid */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 24px;
}

/* 無資料提示 State */
.empty-state {
  grid-column: 1 / -1;
  text-align: center;
  padding: 80px 20px;
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(12px);
}

.empty-state-icon {
  font-size: 3.5rem;
  margin-bottom: 16px;
  opacity: 0.7;
}

.empty-state h3 {
  font-size: 1.4rem;
  margin-bottom: 8px;
  color: var(--text-main);
}

.empty-state p {
  color: var(--text-muted);
  max-width: 400px;
  margin: 0 auto 24px auto;
}

/* 互動網頁卡片 Component */
.card {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--primary-gradient);
  opacity: 0;
  transition: var(--transition);
}

.card:hover {
  background: var(--bg-card-hover);
  border-color: var(--glass-border-hover);
  transform: translateY(-4px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.18);
}

.card:hover::before {
  opacity: 1;
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 12px;
}

.card-vol-tag {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 20px;
  background: rgba(99, 102, 241, 0.15);
  color: var(--primary);
  border: 1px solid var(--glass-border);
  white-space: nowrap;
}

.card-vol-1 { background: rgba(56, 189, 248, 0.15); color: #0284c7; border-color: rgba(56, 189, 248, 0.3); }
.card-vol-2 { background: rgba(168, 85, 247, 0.15); color: #7e22ce; border-color: rgba(168, 85, 247, 0.3); }
.card-vol-3 { background: rgba(236, 72, 153, 0.15); color: #be185d; border-color: rgba(236, 72, 153, 0.3); }
.card-vol-4 { background: rgba(245, 158, 11, 0.15); color: #b45309; border-color: rgba(245, 158, 11, 0.3); }
.card-vol-5 { background: rgba(16, 185, 129, 0.15); color: #047857; border-color: rgba(16, 185, 129, 0.3); }
.card-vol-6 { background: rgba(6, 182, 212, 0.15); color: #0e7490; border-color: rgba(6, 182, 212, 0.3); }

.card-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.4;
  margin-bottom: 8px;
}

.card-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 16px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  height: 2.7em;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 20px;
}

.tag {
  font-size: 0.75rem;
  padding: 2px 8px;
  background: var(--input-bg);
  color: var(--text-muted);
  border: 1px solid var(--glass-border);
  border-radius: 4px;
}

.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 14px;
  border-top: 1px solid var(--glass-border);
}

.card-date {
  font-size: 0.78rem;
  color: var(--text-dim);
}

.card-actions {
  display: flex;
  gap: 6px;
}

/* 模態框 Modal Design */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(3, 7, 18, 0.7);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 1000;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
  opacity: 0;
  pointer-events: none;
  transition: var(--transition);
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-container {
  background: var(--modal-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 620px;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.4);
  transform: scale(0.95);
  transition: var(--transition);
  color: var(--text-main);
}

.modal-overlay.active .modal-container {
  transform: scale(1);
}

.modal-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
}

.modal-close {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  cursor: pointer;
  transition: var(--transition);
}

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

.modal-body {
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
}

.form-control {
  padding: 12px 14px;
  background: var(--input-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-main);
  font-family: var(--font-main);
  font-size: 0.95rem;
  outline: none;
  transition: var(--transition);
}

.form-control option {
  background: var(--modal-bg);
  color: var(--text-main);
}

.form-control:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

textarea.form-control {
  min-height: 90px;
  resize: vertical;
}

/* 檔案拖曳上傳 Zone */
.dropzone {
  border: 2px dashed var(--glass-border);
  background: var(--input-bg);
  border-radius: var(--radius-md);
  padding: 28px 16px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
}

.dropzone:hover, .dropzone.dragover {
  border-color: var(--primary);
  background: var(--bg-card-hover);
}

.dropzone-icon {
  font-size: 2.2rem;
  color: var(--primary);
  margin-bottom: 8px;
}

.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--glass-border);
  display: flex;
  justify-content: flex-end;
  gap: 12px;
}

/* 3. 滿版真全螢幕互動 View Modal Design (True Fullscreen) */
.view-modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: #000000;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.view-modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

/* 頂部全螢幕懸浮工具列 */
.fullscreen-topbar {
  position: absolute;
  top: 16px;
  right: 20px;
  z-index: 10000;
  display: flex;
  align-items: center;
  gap: 12px;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 8px 16px;
  border-radius: 30px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
}

.fullscreen-title {
  color: #ffffff;
  font-size: 0.95rem;
  font-weight: 600;
  max-width: 320px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.fullscreen-exit-btn {
  background: #f43f5e;
  color: #ffffff;
  border: none;
  padding: 6px 14px;
  border-radius: 20px;
  font-weight: 700;
  font-size: 0.85rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: var(--transition);
}

.fullscreen-exit-btn:hover {
  background: #e11d48;
  transform: scale(1.05);
}

.interactive-iframe-full {
  width: 100vw;
  height: 100vh;
  border: none;
  background: #ffffff;
  display: block;
}

/* iOS PWA 引導安裝視窗 */
.ios-prompt-content {
  text-align: center;
  padding: 10px 0;
}

.ios-prompt-icon {
  font-size: 3rem;
  margin-bottom: 10px;
}

/* 頁腳 Footer */
footer {
  text-align: center;
  padding: 24px;
  border-top: 1px solid var(--glass-border);
  color: var(--text-dim);
  font-size: 0.85rem;
  margin-top: 40px;
}

/* 響應式微調 */
@media (max-width: 640px) {
  header { padding: 12px 16px; }
  .brand-title { font-size: 1.15rem; }
  main { padding: 16px 12px; }
  .cards-grid { grid-template-columns: 1fr; }
}