/* ==========================================
   俄羅斯語言科學門戶 - 全域變數與重設 (Variables & Reset)
   ========================================== */
:root {
    /* 配色系統 - 深藍石板灰與金/青色學術點綴 */
    --bg-main: #0b0f19;          /* 深邃學術夜藍 */
    --bg-card: #151e2d;          /* 沉穩石板藍灰卡片 */
    --bg-card-light: #202b3c;    /* 亮色卡片背景 */
    --primary-gold: #eab308;     /* 亮金色點綴 */
    --primary-gold-hover: #ca8a04; /* 深金色懸停 */
    --accent-teal: #14b8a6;      /* 現代智慧青綠 */
    --accent-teal-hover: #0d9488; /* 深青綠懸停 */
    --text-primary: #f8fafc;     /* 溫潤奶油白 */
    --text-secondary: #cbd5e1;   /* 淺灰藍內文 */
    --text-muted: #64748b;       /* 灰藍輔助字 */
    
    --accent-success: #10b981;   /* 答對綠 */
    --accent-error: #ef4444;     /* 答錯紅 */
    
    /* 精緻字型 */
    --font-serif: "Playfair Display", "Noto Serif TC", "Times New Roman", serif;
    --font-sans: "Inter", "Microsoft JhengHei", sans-serif;
    --font-mono: "Fira Code", monospace;
    
    /* 質感陰影與圓角 */
    --card-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
    --hover-shadow: 0 20px 40px rgba(20, 184, 166, 0.15);
    --gold-glow: 0 0 15px rgba(234, 179, 8, 0.25);
    --border-radius: 16px;
    --border-radius-sm: 8px;
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 網頁重設與捲動 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    color: var(--text-secondary);
    background-color: var(--bg-main);
    line-height: 1.8;
    overflow-x: hidden;
}

/* ==========================================
   排版與通用樣式 (Typography & Utilities)
   ========================================== */
h1, h2, h3, h4 {
    font-family: var(--font-serif);
    color: var(--text-primary);
    font-weight: 700;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 100px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header h2 {
    font-size: 2.6rem;
    color: var(--text-primary);
    margin-bottom: 15px;
    position: relative;
    letter-spacing: 1px;
}

.section-header h2::after {
    content: '';
    display: block;
    width: 80px;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-teal), var(--primary-gold));
    margin: 15px auto 0;
    border-radius: 2px;
}

.section-subheader {
    font-size: 1.1rem;
    color: var(--text-muted);
    max-width: 800px;
    margin: 0 auto;
}

/* 標記與徽章 */
.badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.badge-teal {
    background-color: rgba(20, 184, 166, 0.1);
    color: var(--accent-teal);
    border: 1px solid rgba(20, 184, 166, 0.3);
}

.badge-gold {
    background-color: rgba(234, 179, 8, 0.1);
    color: var(--primary-gold);
    border: 1px solid rgba(234, 179, 8, 0.3);
}

/* 按鈕樣式 */
.btn {
    display: inline-block;
    padding: 12px 32px;
    border-radius: 30px;
    font-size: 0.95rem;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition-smooth);
    cursor: pointer;
    border: none;
    font-family: var(--font-sans);
}

.btn-primary {
    background-color: var(--primary-gold);
    color: #0b0f19;
}

.btn-primary:hover {
    background-color: var(--text-primary);
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(234, 179, 8, 0.3);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-primary);
    border: 2px solid rgba(255, 255, 255, 0.2);
    margin-left: 15px;
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.05);
    border-color: var(--text-primary);
    transform: translateY(-3px);
}

/* ==========================================
   導覽列 (Navbar)
   ========================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: rgba(11, 15, 25, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition-smooth);
}

.navbar.scrolled {
    padding: 5px 0;
    background-color: rgba(11, 15, 25, 0.96);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.nav-logo {
    display: flex;
    flex-direction: column;
    text-decoration: none;
    line-height: 1.3;
}

.logo-ru {
    font-family: var(--font-serif);
    font-size: 1.3rem;
    color: var(--primary-gold);
    font-weight: 700;
    letter-spacing: 0.5px;
}

.logo-zh {
    font-size: 0.7rem;
    color: var(--text-secondary);
    letter-spacing: 1.5px;
    text-transform: uppercase;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    transition: var(--transition-smooth);
    position: relative;
    padding: 8px 0;
}

.nav-link:hover {
    color: var(--primary-gold);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-gold);
    transition: var(--transition-smooth);
}

.nav-link:hover::after {
    width: 100%;
}

/* 漢堡排選單 */
.menu-toggle {
    display: none;
    flex-direction: column;
    background: transparent;
    border: none;
    cursor: pointer;
}

.menu-toggle .bar {
    width: 25px;
    height: 2px;
    background-color: var(--text-primary);
    margin: 4px 0;
    transition: var(--transition-smooth);
}

/* ==========================================
   英雄形象區 (Hero Section)
   ========================================== */
.hero {
    height: 100vh;
    background: linear-gradient(135deg, rgba(11, 15, 25, 0.95) 0%, rgba(21, 30, 45, 0.85) 100%), url('hero_bg.jpg') no-repeat center center/cover;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
    overflow: hidden;
    padding-top: 80px;
}

.hero-bg-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) rotate(-8deg);
    font-size: 6.5vw;
    font-weight: 900;
    color: rgba(255, 255, 255, 0.015);
    width: 140%;
    line-height: 1.4;
    pointer-events: none;
    user-select: none;
    white-space: normal;
    word-break: break-all;
    text-align: justify;
    font-family: var(--font-serif);
}

.hero-content {
    position: relative;
    z-index: 10;
    max-width: 900px;
    padding: 0 24px;
}

.hero-tag {
    display: inline-block;
    color: var(--accent-teal);
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 3px;
    text-transform: uppercase;
    margin-bottom: 25px;
    border: 1px solid rgba(20, 184, 166, 0.3);
    padding: 6px 18px;
    border-radius: 20px;
    background-color: rgba(20, 184, 166, 0.05);
}

.hero-title {
    font-size: 3.6rem;
    color: var(--text-primary);
    margin-bottom: 24px;
    line-height: 1.25;
    letter-spacing: 1px;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 45px;
    font-weight: 300;
}

.hero-scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
}

.mouse-icon {
    width: 28px;
    height: 46px;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 15px;
    display: block;
    position: relative;
}

.mouse-icon .wheel {
    width: 4px;
    height: 8px;
    background-color: var(--primary-gold);
    border-radius: 2px;
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    animation: scrollWheel 2s infinite;
}

@keyframes scrollWheel {
    0% { top: 8px; opacity: 1; }
    100% { top: 24px; opacity: 0; }
}

/* ==========================================
   網站導言區 (Intro Section)
   ========================================== */
.intro-section {
    background-color: var(--bg-main);
}

.intro-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 60px;
    align-items: center;
}

.intro-text p {
    margin-bottom: 24px;
    font-size: 1.05rem;
    color: var(--text-secondary);
}

.intro-quote {
    background-color: var(--bg-card);
    padding: 40px;
    border-left: 4px solid var(--primary-gold);
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
    box-shadow: var(--card-shadow);
    border-top: 1px solid rgba(255, 255, 255, 0.03);
    border-right: 1px solid rgba(255, 255, 255, 0.03);
}

.intro-quote blockquote {
    font-family: var(--font-serif);
    font-size: 1.15rem;
    font-style: italic;
    color: var(--text-primary);
    margin-bottom: 20px;
    line-height: 1.7;
}

.intro-quote cite {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--primary-gold);
    font-style: normal;
}

/* ==========================================
   1. 認知語言學區 (Cognitive Section)
   ========================================== */
.cognitive-section {
    background-color: #0f1524;
}

.cognitive-container {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 40px;
    margin-top: 20px;
}

.concept-selector {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.concept-btn {
    background-color: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--border-radius);
    padding: 24px;
    text-align: left;
    cursor: pointer;
    transition: var(--transition-smooth);
    display: flex;
    flex-direction: column;
}

.concept-btn .ru-word {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    color: var(--text-primary);
    font-weight: bold;
    margin-bottom: 4px;
    transition: var(--transition-smooth);
}

.concept-btn .zh-word {
    font-size: 0.85rem;
    color: var(--text-muted);
    letter-spacing: 1px;
}

.concept-btn:hover {
    transform: translateX(5px);
    border-color: rgba(20, 184, 166, 0.3);
    background-color: rgba(20, 184, 166, 0.02);
}

.concept-btn.active {
    border-color: var(--primary-gold);
    background-color: rgba(234, 179, 8, 0.05);
    box-shadow: var(--gold-glow);
}

.concept-btn.active .ru-word {
    color: var(--primary-gold);
}

.concept-btn.active .zh-word {
    color: var(--text-primary);
}

/* 右側展示面板 */
.concept-display-panel {
    position: relative;
}

.concept-card {
    display: none;
    background-color: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 40px;
    box-shadow: var(--card-shadow);
    border: 1px solid rgba(255, 255, 255, 0.04);
    animation: slideIn 0.5s ease forwards;
}

.concept-card.active {
    display: block;
}

@keyframes slideIn {
    from { opacity: 0; transform: translateY(15px); }
    to { opacity: 1; transform: translateY(0); }
}

.concept-header {
    margin-bottom: 30px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    padding-bottom: 20px;
}

.concept-header h3 {
    font-size: 1.8rem;
    color: var(--primary-gold);
    margin-bottom: 10px;
}

.concept-definition {
    font-size: 1.05rem;
    color: var(--text-secondary);
}

.concept-metaphors-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 24px;
}

.metaphor-card {
    background-color: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.04);
    border-radius: var(--border-radius-sm);
    padding: 24px;
    transition: var(--transition-smooth);
}

.metaphor-card:hover {
    background-color: rgba(255, 255, 255, 0.04);
    border-color: rgba(20, 184, 166, 0.2);
}

.metaphor-title {
    display: flex;
    flex-direction: column;
    margin-bottom: 12px;
}

.metaphor-ru {
    font-family: var(--font-serif);
    font-size: 1.25rem;
    color: var(--accent-teal);
    font-weight: 700;
}

.metaphor-zh {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.metaphor-desc {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 15px;
}

.metaphor-example {
    background-color: rgba(0, 0, 0, 0.2);
    border-left: 2px solid var(--primary-gold);
    padding: 10px 15px;
    border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
    margin-top: 10px;
}

.ex-ru {
    font-family: var(--font-serif);
    font-size: 1.05rem;
    color: var(--text-primary);
    font-style: italic;
}

.ex-zh {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 2px;
}

.highlight-word {
    color: var(--primary-gold);
    font-weight: 600;
}

/* ==========================================
   2. 語用學對話分析區 (Pragmatics Section)
   ========================================== */
.pragmatics-section {
    background-color: var(--bg-main);
}

.pragmatics-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    margin-top: 20px;
}

/* 對話模擬器容器 */
.dialogue-simulator {
    background-color: #0d121f;
    border-radius: var(--border-radius);
    border: 1px solid rgba(255, 255, 255, 0.05);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    box-shadow: var(--card-shadow);
}

.dialogue-header {
    background-color: var(--bg-card);
    padding: 15px 20px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--primary-gold);
    letter-spacing: 0.5px;
}

.chat-container {
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.chat-bubble {
    max-width: 85%;
    padding: 15px 20px;
    border-radius: var(--border-radius);
    position: relative;
    cursor: pointer;
    transition: var(--transition-smooth);
    border: 1px solid transparent;
}

.chat-bubble .speaker {
    display: block;
    font-size: 0.8rem;
    font-weight: 700;
    margin-bottom: 4px;
    text-transform: uppercase;
}

.chat-bubble .bubble-text {
    font-size: 0.98rem;
    color: var(--text-primary);
}

.chat-bubble .bubble-hint {
    display: block;
    font-size: 0.7rem;
    color: var(--text-muted);
    text-align: right;
    margin-top: 4px;
    opacity: 0;
    transition: var(--transition-smooth);
}

.chat-bubble:hover .bubble-hint {
    opacity: 1;
}

/* 左側發言者樣式 (Anna) */
.chat-bubble.left {
    align-self: flex-start;
    background-color: var(--bg-card);
    border-bottom-left-radius: 4px;
    border-color: rgba(255, 255, 255, 0.02);
}

.chat-bubble.left .speaker {
    color: var(--accent-teal);
}

/* 右側發言者樣式 (Ivan) */
.chat-bubble.right {
    align-self: flex-end;
    background-color: #1a2538;
    border-bottom-right-radius: 4px;
    border-color: rgba(255, 255, 255, 0.02);
}

.chat-bubble.right .speaker {
    color: var(--primary-gold);
}

/* 氣泡懸浮與激活效果 */
.chat-bubble:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.chat-bubble.active {
    transform: scale(1.02);
    box-shadow: 0 8px 24px rgba(0,0,0,0.3);
}

.chat-bubble.left.active {
    border-color: var(--accent-teal);
    box-shadow: 0 0 15px rgba(20, 184, 166, 0.15);
}

.chat-bubble.right.active {
    border-color: var(--primary-gold);
    box-shadow: 0 0 15px rgba(234, 179, 8, 0.15);
}

/* 右側分析儀面板 */
.pragmatics-analyzer-panel {
    position: relative;
}

.analyzer-card {
    display: none;
    background-color: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 35px;
    box-shadow: var(--card-shadow);
    border: 1px solid rgba(255, 255, 255, 0.04);
    animation: slideIn 0.5s ease forwards;
    height: 100%;
}

.analyzer-card.active {
    display: flex;
    flex-direction: column;
}

.analyzer-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 25px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    padding-bottom: 15px;
}

.analyzer-header h3 {
    font-size: 1.4rem;
    color: var(--text-primary);
}

.analyzer-body {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.analysis-item strong {
    display: block;
    color: var(--primary-gold);
    font-size: 0.9rem;
    margin-bottom: 6px;
    letter-spacing: 0.5px;
}

.analysis-item p {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

/* ==========================================
   3. 語意學前綴映射地圖區 (Semantics Section)
   ========================================== */
.semantics-section {
    background-color: #0f1524;
}

.semantics-grid {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 40px;
    margin-top: 20px;
}

/* 左側構造器 */
.prefix-builder-box {
    background-color: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 35px;
    box-shadow: var(--card-shadow);
    border: 1px solid rgba(255, 255, 255, 0.04);
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.builder-section h4 {
    font-size: 1.05rem;
    color: var(--text-primary);
    margin-bottom: 15px;
    position: relative;
    padding-left: 10px;
}

.builder-section h4::before {
    content: '';
    position: absolute;
    left: 0;
    top: 4px;
    width: 3px;
    height: 14px;
    background-color: var(--accent-teal);
}

/* 根詞選擇 */
.root-selector {
    display: flex;
    gap: 15px;
}

.root-btn {
    background-color: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    color: var(--text-secondary);
    border-radius: var(--border-radius-sm);
    padding: 10px 20px;
    font-family: var(--font-mono);
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition-smooth);
}

.root-btn:hover {
    border-color: var(--accent-teal);
    color: var(--accent-teal);
}

.root-btn.active {
    background-color: rgba(20, 184, 166, 0.1);
    border-color: var(--accent-teal);
    color: var(--text-primary);
    box-shadow: 0 0 12px rgba(20, 184, 166, 0.2);
}

/* 前綴選擇 */
.prefix-selector {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}

.prefix-btn {
    background-color: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.06);
    color: var(--text-secondary);
    border-radius: var(--border-radius-sm);
    padding: 12px;
    cursor: pointer;
    transition: var(--transition-smooth);
    display: flex;
    flex-direction: column;
    align-items: center;
    font-family: var(--font-mono);
    font-size: 1.05rem;
    font-weight: bold;
}

.prefix-btn .pref-desc {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: normal;
    color: var(--text-muted);
    margin-top: 3px;
    text-align: center;
}

.prefix-btn:hover {
    border-color: var(--primary-gold);
    background-color: rgba(234, 179, 8, 0.02);
}

.prefix-btn.active {
    background-color: rgba(234, 179, 8, 0.08);
    border-color: var(--primary-gold);
    color: var(--primary-gold);
    box-shadow: 0 0 10px rgba(234, 179, 8, 0.15);
}

.prefix-btn.active .pref-desc {
    color: var(--text-primary);
}

/* 運算結果 */
.builder-result {
    border-top: 1px dashed rgba(255, 255, 255, 0.08);
    padding-top: 25px;
}

.result-word-card {
    background: linear-gradient(135deg, #101726 0%, #1a253a 100%);
    border-radius: var(--border-radius-sm);
    padding: 20px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
}

.formula {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    color: var(--text-muted);
}

.formula #form-pref {
    color: var(--primary-gold);
    font-weight: bold;
}

.formula #form-root {
    color: var(--text-secondary);
}

.arrow {
    color: var(--text-muted);
    font-size: 1.2rem;
}

.new-verb {
    font-family: var(--font-serif);
    font-size: 1.6rem;
    font-weight: bold;
    color: var(--text-primary);
    letter-spacing: 0.5px;
}

.verb-aspect {
    background-color: var(--accent-teal);
    color: #0b0f19;
    font-size: 0.75rem;
    font-weight: 700;
    padding: 3px 8px;
    border-radius: 4px;
    text-transform: uppercase;
}

/* 右側映射地圖 */
.semantic-map-box {
    background-color: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 30px;
    box-shadow: var(--card-shadow);
    border: 1px solid rgba(255, 255, 255, 0.04);
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.map-title {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-muted);
    letter-spacing: 0.5px;
    text-transform: uppercase;
    text-align: center;
}

/* 地圖可視化區域 */
.map-visualizer {
    position: relative;
    width: 100%;
    height: 360px;
    background-color: #0b0f19;
    border-radius: var(--border-radius-sm);
    border: 1px solid rgba(255, 255, 255, 0.03);
    overflow: hidden;
}

.map-connections {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
}

.map-connections line {
    stroke: rgba(255, 255, 255, 0.08);
    stroke-width: 2;
    stroke-dasharray: 4;
    transition: var(--transition-smooth);
}

.map-connections line.active {
    stroke: var(--accent-teal);
    stroke-width: 3;
    stroke-dasharray: 0;
    filter: drop-shadow(0 0 6px var(--accent-teal));
}

.map-connections line.active-gold {
    stroke: var(--primary-gold);
    stroke-width: 3;
    stroke-dasharray: 0;
    filter: drop-shadow(0 0 6px var(--primary-gold));
}

/* 地圖節點 */
.map-node {
    position: absolute;
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    z-index: 2;
    transition: var(--transition-smooth);
    user-select: none;
}

.node-center {
    width: 90px;
    height: 90px;
    top: 135px;
    left: calc(50% - 45px);
    background: radial-gradient(circle, var(--bg-card-light) 0%, #1e1b4b 100%);
    border: 2px solid var(--primary-gold);
    box-shadow: var(--gold-glow);
    z-index: 5;
}

.node-center .node-center-text {
    font-family: var(--font-serif);
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
}

.node-center .node-zh {
    font-size: 0.65rem;
    color: var(--text-muted);
    margin-top: 1px;
}

.node-edge {
    width: 90px;
    height: 90px;
    background-color: var(--bg-card-light);
    border: 1px solid rgba(255, 255, 255, 0.08);
    padding: 8px;
    cursor: default;
}

.node-edge .node-label {
    font-size: 0.7rem;
    font-weight: bold;
    color: var(--text-secondary);
    line-height: 1.2;
}

.node-edge .node-value {
    font-family: var(--font-mono);
    font-size: 0.6rem;
    color: var(--text-muted);
    margin-top: 2px;
}

/* 激活態節點 */
.node-edge.active {
    background-color: rgba(20, 184, 166, 0.15);
    border-color: var(--accent-teal);
    box-shadow: 0 0 15px rgba(20, 184, 166, 0.3);
    transform: scale(1.08);
}

.node-edge.active .node-label {
    color: var(--text-primary);
}

.node-edge.active .node-value {
    color: var(--accent-teal);
}

/* 說明解析卡片 */
.map-explanation-card {
    background-color: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.04);
    border-radius: var(--border-radius-sm);
    padding: 20px;
}

.map-explanation-card h4 {
    font-size: 1.1rem;
    color: var(--primary-gold);
    margin-bottom: 8px;
}

.explain-text {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.explain-example {
    background-color: rgba(0, 0, 0, 0.2);
    border-left: 2px solid var(--accent-teal);
    padding: 10px 15px;
    border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
}

/* ==========================================
   4. 綜合學術挑戰區 (Quiz)
   ========================================== */
.quiz-section {
    background-color: var(--bg-main);
}

.quiz-container {
    max-width: 750px;
    margin: 0 auto;
    background-color: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 45px;
    box-shadow: var(--card-shadow);
    border: 1px solid rgba(255, 255, 255, 0.04);
}

.quiz-progress {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

.progress-bar {
    flex-grow: 1;
    height: 6px;
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: 3px;
    margin-right: 20px;
    position: relative;
    overflow: hidden;
}

.progress-bar::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: var(--progress, 16.6%);
    background: linear-gradient(90deg, var(--accent-teal), var(--primary-gold));
    transition: width 0.4s ease;
}

.progress-text {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
}

.quiz-question-box {
    background-color: rgba(0, 0, 0, 0.15);
    border-radius: var(--border-radius-sm);
    padding: 30px;
    margin-bottom: 30px;
    text-align: center;
    border-left: 4px solid var(--accent-teal);
}

.quiz-sentence {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    color: var(--text-primary);
    font-weight: 700;
    margin-bottom: 12px;
}

.quiz-sentence span.highlight {
    color: var(--primary-gold);
    border-bottom: 2px dashed var(--primary-gold);
    padding-bottom: 2px;
}

.quiz-translation {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.quiz-hint {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-style: italic;
}

.quiz-options {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.option-btn {
    background-color: var(--bg-card-light);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--border-radius-sm);
    padding: 18px 24px;
    font-family: var(--font-sans);
    font-size: 0.98rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-smooth);
    text-align: left;
}

.option-btn:hover:not(:disabled) {
    border-color: var(--primary-gold);
    background-color: rgba(234, 179, 8, 0.03);
    transform: translateY(-2px);
}

.option-btn.correct {
    background-color: rgba(16, 185, 129, 0.1);
    border-color: var(--accent-success);
    color: var(--accent-success);
}

.option-btn.wrong {
    background-color: rgba(239, 68, 68, 0.1);
    border-color: var(--accent-error);
    color: var(--accent-error);
}

.option-btn:disabled {
    cursor: not-allowed;
    opacity: 0.6;
}

.quiz-feedback {
    margin-top: 30px;
    padding: 30px;
    border-radius: var(--border-radius-sm);
    animation: fadeIn 0.4s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.quiz-feedback.correct-bg {
    background-color: rgba(16, 185, 129, 0.05);
    border: 1px solid rgba(16, 185, 129, 0.15);
}

.quiz-feedback.wrong-bg {
    background-color: rgba(239, 68, 68, 0.05);
    border: 1px solid rgba(239, 68, 68, 0.15);
}

.feedback-icon {
    font-size: 2.6rem;
    margin-bottom: 12px;
}

.feedback-message {
    font-weight: 700;
    font-size: 1.15rem;
    margin-bottom: 8px;
}

.quiz-feedback.correct-bg .feedback-message {
    color: var(--accent-success);
}

.quiz-feedback.wrong-bg .feedback-message {
    color: var(--accent-error);
}

.feedback-explanation {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 25px;
}

/* 結算頁面 */
.quiz-results {
    text-align: center;
    animation: fadeIn 0.6s ease;
}

.quiz-results h3 {
    font-size: 2.2rem;
    color: var(--primary-gold);
    margin-bottom: 25px;
}

.score-circle {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    border: 4px solid var(--accent-teal);
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0 auto 30px;
    box-shadow: 0 0 20px rgba(20, 184, 166, 0.1);
}

.score-num {
    font-size: 3rem;
    font-weight: 700;
    color: var(--text-primary);
}

.score-total {
    font-size: 1.2rem;
    color: var(--text-muted);
    margin-left: 2px;
}

.result-message {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 35px;
}

.hidden {
    display: none !important;
}

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

/* ==========================================
   5. 重要語言學家區 (Scholars Timeline)
   ========================================== */
.scholars-section {
    background-color: #0f1524;
}

.scholars-timeline {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
    margin-top: 20px;
}

.scholar-timeline-card {
    background-color: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.04);
    border-radius: var(--border-radius);
    padding: 35px;
    box-shadow: var(--card-shadow);
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.scholar-timeline-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-teal), var(--primary-gold));
    opacity: 0;
    transition: var(--transition-smooth);
}

.scholar-timeline-card:hover {
    transform: translateY(-8px);
    border-color: rgba(20, 184, 166, 0.2);
    box-shadow: var(--hover-shadow);
}

.scholar-timeline-card:hover::before {
    opacity: 1;
}

.scholar-badge {
    position: absolute;
    top: 20px;
    right: 20px;
    font-size: 0.7rem;
    font-weight: bold;
    color: var(--primary-gold);
    border: 1px solid rgba(234, 179, 8, 0.3);
    background-color: rgba(234, 179, 8, 0.05);
    padding: 3px 10px;
    border-radius: 20px;
}

.scholar-header {
    margin-bottom: 20px;
}

.scholar-header h3 {
    font-size: 1.45rem;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.scholar-ru-name {
    display: block;
    font-family: var(--font-serif);
    font-size: 0.85rem;
    color: var(--text-muted);
}

.scholar-tagline {
    font-style: italic;
    font-size: 0.95rem;
    color: var(--accent-teal);
    line-height: 1.5;
    border-left: 2px solid var(--accent-teal);
    padding-left: 12px;
    margin-bottom: 20px;
}

.scholar-content strong {
    display: block;
    font-size: 0.85rem;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.scholar-content ul {
    list-style: none;
}

.scholar-content li {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 12px;
    position: relative;
    padding-left: 15px;
}

.scholar-content li::before {
    content: '✦';
    color: var(--primary-gold);
    position: absolute;
    left: 0;
    font-size: 0.75rem;
}

/* ==========================================
   頁尾 (Footer)
   ========================================== */
.footer {
    background-color: #070a12;
    padding: 60px 0;
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.03);
}

.footer-title {
    font-size: 1.5rem;
    color: var(--primary-gold);
    margin-bottom: 12px;
}

.footer-desc {
    font-size: 0.9rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto 30px;
}

.footer-divider {
    height: 1px;
    background-color: rgba(255, 255, 255, 0.05);
    max-width: 80px;
    margin: 0 auto 30px;
}

.copyright {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ==========================================
   響應式設計 (Responsive Design)
   ========================================== */
@media (max-width: 992px) {
    .section-header h2 { font-size: 2.2rem; }
    .intro-grid { grid-template-columns: 1fr; gap: 40px; }
    .cognitive-container { grid-template-columns: 1fr; }
    .pragmatics-grid { grid-template-columns: 1fr; }
    .semantics-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
    html { font-size: 15px; }
    .nav-menu {
        position: fixed;
        top: 80px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 80px);
        background-color: rgba(11, 15, 25, 0.98);
        flex-direction: column;
        align-items: center;
        padding-top: 50px;
        gap: 25px;
        transition: var(--transition-smooth);
        z-index: 999;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .menu-toggle {
        display: flex;
    }
    
    /* 漢堡排選單動畫 */
    .menu-toggle.active .bar:nth-child(1) {
        transform: translateY(10px) rotate(45deg);
    }
    .menu-toggle.active .bar:nth-child(2) {
        opacity: 0;
    }
    .menu-toggle.active .bar:nth-child(3) {
        transform: translateY(-10px) rotate(-45deg);
    }
    
    .hero-title { font-size: 2.4rem; }
    .hero-subtitle { font-size: 1.1rem; }
    .quiz-options { grid-template-columns: 1fr; }
    .prefix-selector { grid-template-columns: repeat(2, 1fr); }
}