/* ============================================
   怦怦AI - Main Stylesheet
   Mobile-first responsive design
   ============================================ */

:root {
    --primary: #667eea;
    --primary-dark: #5a67d8;
    --secondary: #764ba2;
    --accent: #f5576c;
    --pink: #f093fb;
    --purple: #a855f7;
    --blue: #3b82f6;
    --gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-pink: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-soft: linear-gradient(135deg, #e0c3fc 0%, #8ec5fc 100%);
    --text: #1a1a2e;
    --text-light: #64748b;
    --text-muted: #94a3b8;
    --bg: #ffffff;
    --bg-light: #f8fafc;
    --bg-dark: #0f172a;
    --border: #e2e8f0;
    --border-light: #f1f5f9;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow: 0 4px 6px -1px rgba(0,0,0,0.1);
    --shadow-md: 0 10px 15px -3px rgba(0,0,0,0.1);
    --shadow-lg: 0 20px 25px -5px rgba(0,0,0,0.1);
    --shadow-xl: 0 25px 50px -12px rgba(0,0,0,0.25);
    --radius: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --safe-top: env(safe-area-inset-top, 0px);
    --safe-bottom: env(safe-area-inset-bottom, 0px);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
    scroll-padding-top: 70px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.7;
    color: var(--text);
    background: var(--bg);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: var(--transition);
}

a:hover { color: var(--primary-dark); }

ul, ol { list-style: none; }

button {
    cursor: pointer;
    border: none;
    background: none;
    font-family: inherit;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 32px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    color: var(--text);
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.75rem, 4vw, 2.5rem); }
h3 { font-size: clamp(1.25rem, 3vw, 1.5rem); }

p { color: var(--text-light); }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 32px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius);
    transition: var(--transition);
    cursor: pointer;
    text-align: center;
    white-space: nowrap;
    -webkit-tap-highlight-color: transparent;
}

.btn-primary {
    background: var(--gradient);
    color: #fff;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.5);
    color: #fff;
}

.btn-secondary {
    background: #fff;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-secondary:hover {
    background: var(--primary);
    color: #fff;
}

.btn-large {
    padding: 18px 44px;
    font-size: 1.1rem;
    border-radius: var(--radius-lg);
}

.btn-block {
    display: flex;
    width: 100%;
}

/* Header / Navigation */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: var(--shadow-sm);
    z-index: 999;
    padding-top: var(--safe-top);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--text);
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: var(--gradient);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    color: #fff;
    overflow: hidden;
    flex-shrink: 0;
}

.logo-icon img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 12px;
}

.logo span {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 32px;
}

.main-nav a {
    color: var(--text);
    font-weight: 500;
    font-size: 0.95rem;
    position: relative;
}

.main-nav a:hover { color: var(--primary); }

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: -6px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient);
    transition: width 0.3s ease;
}

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

.nav-toggle {
    display: none;
    width: 40px;
    height: 40px;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
    color: var(--text);
}

.nav-toggle:hover { background: var(--bg-light); }

/* Hero Section */
.hero {
    padding: 160px 0 80px;
    background: linear-gradient(180deg, #f8fafc 0%, #ffffff 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -200px;
    right: -200px;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(102, 126, 234, 0.15) 0%, transparent 70%);
    border-radius: 50%;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -150px;
    left: -150px;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(240, 147, 251, 0.12) 0%, transparent 70%);
    border-radius: 50%;
}

.hero-content {
    text-align: center;
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 16px;
    background: rgba(102, 126, 234, 0.1);
    color: var(--primary);
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.hero-title {
    margin-bottom: 20px;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(1.05rem, 2.5vw, 1.25rem);
    color: var(--text-light);
    max-width: 700px;
    margin: 0 auto 30px;
    line-height: 1.8;
}

.hero-keywords {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
    margin-bottom: 36px;
}

.hero-keywords span {
    padding: 6px 16px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 100px;
    font-size: 0.85rem;
    color: var(--text-light);
    box-shadow: var(--shadow-sm);
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 16px;
    margin-bottom: 48px;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 48px;
    flex-wrap: wrap;
}

.hero-stat {
    text-align: center;
}

.hero-stat-number {
    font-size: 2rem;
    font-weight: 800;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-stat-label {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Hero Showcase Image */
.hero-showcase {
    margin-top: 56px;
    text-align: center;
    position: relative;
    z-index: 1;
}

.hero-showcase-img {
    max-width: 320px;
    width: 100%;
    margin: 0 auto;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    display: block;
    transition: var(--transition);
}

.hero-showcase-img:hover {
    transform: translateY(-6px);
}

/* Character Screenshot */
.character-screenshot {
    grid-column: 1 / -1;
    margin-top: 32px;
    text-align: center;
}

.character-screenshot img {
    max-width: 100%;
    max-height: 500px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    margin: 0 auto;
    display: block;
}

.character-screenshot-caption {
    margin-top: 12px;
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Scenario Image */
.scenario-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* Tutorial Screenshot */
.tutorial-showcase {
    margin-top: 48px;
    text-align: center;
}

.tutorial-showcase img {
    max-width: 100%;
    max-height: 400px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    margin: 0 auto;
    display: block;
}

/* Download QR Code */
.download-qr {
    width: 180px;
    height: 180px;
    margin: 24px auto 0;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    display: block;
    background: #fff;
    padding: 8px;
}

.download-qr-text {
    text-align: center;
    margin-top: 12px;
    font-size: 0.9rem;
    color: var(--text-light);
}

/* Sections */
.section {
    padding: 80px 0;
}

.section-alt { background: var(--bg-light); }

.section-header {
    text-align: center;
    margin-bottom: 56px;
}

.section-title {
    margin-bottom: 16px;
}

.section-subtitle {
    font-size: 1.05rem;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.feature-card {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border-light);
}

.feature-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-xl);
}

.feature-icon {
    width: 56px;
    height: 56px;
    background: var(--gradient);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: #fff;
}

.feature-card h3 {
    margin-bottom: 12px;
    font-size: 1.2rem;
}

.feature-card p {
    font-size: 0.95rem;
    line-height: 1.7;
}

/* Characters Section */
.characters-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.character-card {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 24px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border-light);
}

.character-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.character-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    margin: 0 auto 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    color: #fff;
    font-weight: 700;
}

.character-card h4 {
    font-size: 1.1rem;
    margin-bottom: 6px;
}

.character-card .character-type {
    font-size: 0.85rem;
    color: var(--primary);
    font-weight: 500;
}

/* Scenarios */
.scenarios-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.scenario-card {
    background: #fff;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.scenario-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.scenario-banner {
    height: 140px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: #fff;
}

.scenario-content {
    padding: 24px;
}

.scenario-content h3 {
    margin-bottom: 10px;
    font-size: 1.15rem;
}

.scenario-content p {
    font-size: 0.9rem;
}

/* Tutorial Steps */
.tutorial-steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    counter-reset: step;
}

.tutorial-step {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 32px 24px;
    text-align: center;
    box-shadow: var(--shadow);
    position: relative;
    counter-increment: step;
}

.tutorial-step::before {
    content: counter(step);
    position: absolute;
    top: -20px;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 40px;
    background: var(--gradient);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.1rem;
}

.tutorial-step h3 {
    margin: 12px 0 10px;
    font-size: 1.1rem;
}

.tutorial-step p {
    font-size: 0.9rem;
}

/* Comparison Table */
.comparison-section {
    background: var(--bg-light);
}

.comparison-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.comparison-card {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 32px 28px;
    box-shadow: var(--shadow);
    text-align: center;
}

.comparison-card.featured {
    background: var(--gradient);
    color: #fff;
    transform: scale(1.02);
}

.comparison-card.featured h3,
.comparison-card.featured p {
    color: #fff;
}

.comparison-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.comparison-card h3 {
    margin-bottom: 12px;
}

.comparison-card ul {
    text-align: left;
    margin-top: 20px;
}

.comparison-card li {
    padding: 8px 0;
    border-bottom: 1px solid var(--border-light);
    font-size: 0.9rem;
    color: var(--text-light);
}

.comparison-card.featured li {
    border-bottom-color: rgba(255,255,255,0.2);
    color: rgba(255,255,255,0.9);
}

.comparison-card li:last-child { border-bottom: none; }

/* Testimonials */
.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.testimonial-card {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-light);
    transition: var(--transition);
}

.testimonial-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.testimonial-stars {
    color: #fbbf24;
    font-size: 1.1rem;
    margin-bottom: 16px;
    letter-spacing: 2px;
}

.testimonial-card h4 {
    font-size: 1.05rem;
    margin-bottom: 12px;
}

.testimonial-text {
    font-size: 0.92rem;
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 20px;
    font-style: italic;
}

.testimonial-user {
    display: flex;
    align-items: center;
    gap: 12px;
    padding-top: 16px;
    border-top: 1px solid var(--border-light);
}

.user-avatar {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 600;
    font-size: 0.95rem;
}

.testimonial-user strong {
    display: block;
    font-size: 0.95rem;
    color: var(--text);
}

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

/* Download Section */
.download-section {
    background: var(--gradient);
    color: #fff;
    padding: 80px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.download-section::before {
    content: '';
    position: absolute;
    top: -100px;
    left: -100px;
    width: 300px;
    height: 300px;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
}

.download-section::after {
    content: '';
    position: absolute;
    bottom: -80px;
    right: -80px;
    width: 250px;
    height: 250px;
    background: rgba(255,255,255,0.08);
    border-radius: 50%;
}

.download-content {
    position: relative;
    z-index: 1;
}

.download-section h2 {
    color: #fff;
    margin-bottom: 16px;
}

.download-section p {
    color: rgba(255,255,255,0.9);
    font-size: 1.1rem;
    margin-bottom: 32px;
}

.download-buttons {
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 32px;
}

.download-btn {
    background: #fff;
    color: var(--primary);
    padding: 16px 40px;
    border-radius: var(--radius-lg);
    font-weight: 700;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    transition: var(--transition);
    font-size: 1rem;
}

.download-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    color: var(--primary-dark);
}

.download-info {
    display: flex;
    justify-content: center;
    gap: 32px;
    flex-wrap: wrap;
    font-size: 0.9rem;
    color: rgba(255,255,255,0.8);
}

.download-info span {
    display: flex;
    align-items: center;
    gap: 6px;
}

/* FAQ */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: #fff;
    border-radius: var(--radius);
    margin-bottom: 16px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    padding: 20px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text);
    text-align: left;
    transition: var(--transition);
}

.faq-question:hover {
    background: var(--bg-light);
}

.faq-icon {
    flex-shrink: 0;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    transition: transform 0.3s ease;
    font-size: 1.2rem;
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-answer-inner {
    padding: 0 24px 20px;
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.8;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

/* Keywords Cloud */
.keywords-section {
    padding: 60px 0;
    background: var(--bg-light);
}

.keywords-title {
    text-align: center;
    margin-bottom: 32px;
    font-size: 1.3rem;
}

.keywords-cloud {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
    max-width: 800px;
    margin: 0 auto;
}

.keywords-cloud a {
    padding: 8px 20px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 100px;
    font-size: 0.9rem;
    color: var(--text-light);
    transition: var(--transition);
}

.keywords-cloud a:hover {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
    transform: translateY(-2px);
}

/* Footer */
.site-footer {
    background: var(--bg-dark);
    color: rgba(255,255,255,0.7);
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    margin-bottom: 40px;
}

.footer-col h4 {
    color: #fff;
    font-size: 1rem;
    margin-bottom: 20px;
}

.footer-col a {
    color: rgba(255,255,255,0.7);
    font-size: 0.9rem;
    display: block;
    padding: 6px 0;
    transition: var(--transition);
}

.footer-col a:hover { color: #fff; }

.footer-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
    color: #fff;
    font-size: 1.3rem;
    font-weight: 700;
}

.footer-desc {
    font-size: 0.9rem;
    line-height: 1.8;
    margin-bottom: 16px;
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: 24px;
    text-align: center;
    font-size: 0.85rem;
}

.footer-bottom p {
    color: rgba(255,255,255,0.5);
}

/* Mobile Nav */
.mobile-nav {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: #fff;
    box-shadow: 0 -2px 20px rgba(0, 0, 0, 0.08);
    z-index: 998;
    padding: 8px 0;
    padding-bottom: calc(8px + var(--safe-bottom));
}

.mobile-nav-list {
    display: flex;
    justify-content: space-around;
    align-items: center;
}

.mobile-nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3px;
    padding: 6px 12px;
    text-decoration: none;
    color: var(--text-muted);
    font-size: 0.72rem;
    font-weight: 500;
    transition: var(--transition);
    border-radius: 8px;
    min-width: 48px;
    -webkit-tap-highlight-color: transparent;
}

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

.mobile-nav-icon {
    font-size: 1.3rem;
    line-height: 1;
}

.mobile-nav-download {
    background: var(--gradient);
    color: #fff !important;
    border-radius: 12px;
    padding: 8px 14px !important;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.mobile-nav-download .mobile-nav-icon {
    font-size: 1.4rem;
}

/* FAB Download Button */
.fab-download {
    display: flex;
    position: fixed;
    right: 20px;
    bottom: 100px;
    width: 56px;
    height: 56px;
    background: var(--gradient);
    color: #fff;
    border-radius: 50%;
    align-items: center;
    justify-content: center;
    box-shadow: 0 6px 24px rgba(102, 126, 234, 0.5);
    z-index: 997;
    font-size: 1.5rem;
    transition: var(--transition);
    text-decoration: none;
}

.fab-download:active {
    transform: scale(0.92);
}

/* Download Page Specific */
.download-hero {
    padding: 140px 0 60px;
    background: linear-gradient(180deg, #f8fafc 0%, #ffffff 100%);
    text-align: center;
}

.download-hero h1 {
    margin-bottom: 16px;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.download-card {
    max-width: 500px;
    margin: 0 auto;
    background: #fff;
    border-radius: var(--radius-xl);
    padding: 48px 40px;
    box-shadow: var(--shadow-xl);
    text-align: center;
    border: 1px solid var(--border-light);
}

.download-card h2 {
    margin-bottom: 8px;
}

.download-card .version-info {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 28px;
}

.download-card .btn-download-large {
    width: 100%;
    padding: 20px;
    font-size: 1.1rem;
    border-radius: var(--radius-lg);
    background: var(--gradient);
    color: #fff;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-bottom: 20px;
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
    transition: var(--transition);
}

.download-card .btn-download-large:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 35px rgba(102, 126, 234, 0.5);
}

.download-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-light);
}

.download-feature {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
    color: var(--text-light);
}

.download-feature::before {
    content: '✓';
    color: var(--primary);
    font-weight: 700;
}

/* Install Steps */
.install-steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin: 48px 0;
}

.install-step {
    text-align: center;
    padding: 32px 24px;
}

.install-step-number {
    width: 48px;
    height: 48px;
    background: var(--gradient);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
    margin: 0 auto 16px;
}

.install-step h3 {
    margin-bottom: 8px;
}

.install-step p {
    font-size: 0.9rem;
}

/* Obfuscated download text display */
.download-url-display {
    word-break: break-all;
    font-family: monospace;
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* ============ Responsive Design ============ */

/* Tablet & Small Desktop */
@media (max-width: 1024px) {
    .container { padding: 0 24px; }

    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .characters-grid { grid-template-columns: repeat(3, 1fr); }
    .scenarios-grid { grid-template-columns: repeat(2, 1fr); }
    .comparison-grid { grid-template-columns: repeat(2, 1fr); }
    .testimonials-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }

    .testimonials-grid { grid-template-columns: repeat(2, 1fr); }
}

/* Mobile */
@media (max-width: 768px) {
    .container { padding: 0 16px; }

    /* Header */
    .header-inner { height: 56px; }
    .logo { font-size: 1.1rem; }
    .logo-icon { width: 34px; height: 34px; border-radius: 10px; }
    .logo-icon img { width: 100%; height: 100%; }
    .main-nav { display: none; }
    .nav-toggle { display: flex; width: 38px; height: 38px; }

    /* Hero */
    .hero { padding: 100px 0 40px; }
    .hero-title { font-size: 1.65rem; line-height: 1.35; }
    .hero-subtitle { font-size: 0.92rem; line-height: 1.7; }
    .hero-actions { flex-direction: column; align-items: stretch; gap: 12px; }
    .hero-actions .btn { width: 100%; }
    .hero-keywords { gap: 6px; margin-bottom: 28px; }
    .hero-keywords span { font-size: 0.78rem; padding: 4px 12px; }
    .hero-stats { gap: 16px; }
    .hero-stat { flex: 1; min-width: 0; }
    .hero-stat-number { font-size: 1.3rem; }
    .hero-stat-label { font-size: 0.72rem; }
    .hero-showcase { margin-top: 32px; }
    .hero-showcase-img { max-width: 240px; }

    /* Sections */
    .section { padding: 40px 0; }
    .section-header { margin-bottom: 28px; }
    .section-title { font-size: 1.4rem; }
    .section-subtitle { font-size: 0.9rem; }

    /* Grids - all single column on mobile */
    .features-grid { grid-template-columns: 1fr; gap: 14px; }
    .characters-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
    .scenarios-grid { grid-template-columns: 1fr; gap: 14px; }
    .tutorial-steps { grid-template-columns: 1fr; gap: 24px; }
    .comparison-grid { grid-template-columns: 1fr; gap: 14px; }
    .testimonials-grid { grid-template-columns: 1fr; gap: 14px; }
    .install-steps { grid-template-columns: 1fr; gap: 20px; }

    .comparison-card.featured { transform: none; }

    /* Cards */
    .feature-card { padding: 24px 20px; }
    .feature-icon { width: 48px; height: 48px; font-size: 1.3rem; margin-bottom: 16px; }
    .feature-card h3 { font-size: 1.08rem; }
    .feature-card p { font-size: 0.9rem; }
    .testimonial-card { padding: 24px 20px; }

    /* Character card mobile */
    .character-card { padding: 20px 14px; }
    .character-avatar { width: 64px; height: 64px; font-size: 1.4rem; margin-bottom: 12px; }
    .character-card h4 { font-size: 0.95rem; }
    .character-type { font-size: 0.78rem; }
    .character-screenshot img { max-height: 300px; border-radius: var(--radius); }
    .character-screenshot-caption { font-size: 0.82rem; }

    /* Scenario card mobile */
    .scenario-banner { height: 180px; position: relative; overflow: hidden; }
    .scenario-banner .scenario-img { position: absolute; inset: 0; width: 100%; height: 100%; }
    .scenario-banner:has(.scenario-img)::after {
        content: '';
        position: absolute;
        inset: 0;
        background: linear-gradient(180deg, rgba(102,126,234,0.15) 0%, rgba(118,75,162,0.15) 100%);
    }
    .scenario-content { padding: 20px; }
    .scenario-content h3 { font-size: 1.05rem; }
    .scenario-content p { font-size: 0.88rem; }

    /* Tutorial steps mobile */
    .tutorial-step { padding: 28px 20px 24px; }
    .tutorial-step::before { width: 36px; height: 36px; font-size: 1rem; top: -18px; }
    .tutorial-step h3 { font-size: 1rem; }
    .tutorial-step p { font-size: 0.88rem; }
    .tutorial-showcase img { max-height: 280px; }

    /* Comparison card mobile */
    .comparison-card { padding: 24px 20px; }
    .comparison-icon { font-size: 2rem; margin-bottom: 12px; }
    .comparison-card h3 { font-size: 1.05rem; margin-bottom: 8px; }
    .comparison-card li { font-size: 0.85rem; padding: 6px 0; }

    /* Testimonial mobile */
    .testimonial-stars { font-size: 0.95rem; margin-bottom: 12px; }
    .testimonial-text { font-size: 0.88rem; line-height: 1.75; }
    .user-avatar { width: 38px; height: 38px; font-size: 0.85rem; }

    /* Footer */
    .footer-grid { grid-template-columns: 1fr; gap: 24px; }
    .site-footer { padding: 32px 0 88px; }
    .footer-col h4 { margin-bottom: 14px; }
    .footer-col a { padding: 5px 0; font-size: 0.88rem; }
    .footer-desc { font-size: 0.88rem; }
    .footer-brand { font-size: 1.1rem; }
    .footer-brand .logo-icon { width: 30px; height: 30px; }

    /* Mobile Nav */
    .mobile-nav { display: block; padding: 6px 0; padding-bottom: calc(6px + var(--safe-bottom)); }
    .mobile-nav-list { gap: 2px; }
    .mobile-nav-item {
        font-size: 0.7rem;
        padding: 6px 6px;
        min-width: 0;
        min-height: 44px;
        justify-content: center;
    }
    .mobile-nav-icon { font-size: 1.2rem; }
    .mobile-nav-download { padding: 6px 10px !important; border-radius: 10px; }
    body { padding-bottom: calc(64px + var(--safe-bottom)); }

    /* FAB */
    .fab-download { display: flex; width: 52px; height: 52px; right: 14px; bottom: 88px; }

    /* Download Section */
    .download-section { padding: 40px 0; }
    .download-buttons { flex-direction: column; align-items: stretch; gap: 12px; }
    .download-btn { width: 100%; justify-content: center; padding: 14px 24px; font-size: 0.95rem; }
    .download-info { gap: 12px; font-size: 0.82rem; flex-direction: column; align-items: center; }

    /* Download Card */
    .download-card { padding: 28px 22px; margin: 0 12px; }
    .download-card h2 { font-size: 1.25rem; }
    .download-card .version-info { font-size: 0.82rem; margin-bottom: 20px; }
    .download-card .btn-download-large { padding: 16px; font-size: 1rem; }
    .download-qr { width: 140px; height: 140px; margin-top: 20px; }
    .download-qr-text { font-size: 0.82rem; }

    /* Install Steps */
    .install-steps { margin: 32px 0; }
    .install-step { padding: 24px 20px; }
    .install-step-number { width: 40px; height: 40px; font-size: 1rem; margin-bottom: 12px; }
    .install-step h3 { font-size: 1.05rem; margin-bottom: 6px; }
    .install-step p { font-size: 0.88rem; }

    /* FAQ */
    .faq-question { font-size: 0.9rem; padding: 16px 16px; }
    .faq-answer-inner { padding: 0 16px 16px; font-size: 0.86rem; line-height: 1.75; }

    /* Keywords */
    .keywords-cloud { gap: 8px; }
    .keywords-cloud a { padding: 6px 14px; font-size: 0.82rem; }

    /* Buttons */
    .btn { padding: 14px 24px; font-size: 0.95rem; min-height: 44px; }
    .btn-large { padding: 16px 28px; font-size: 1rem; }

    /* Download Hero */
    .download-hero { padding: 100px 0 40px; }
    .download-hero h1 { font-size: 1.65rem; }

    /* CTA Section */
    h2#ctaTitle { font-size: 1.4rem !important; }

    /* Touch Optimizations */
    *, *::before, *::after {
        -webkit-tap-highlight-color: transparent;
        -webkit-touch-callout: none;
    }
    .btn:active { transform: scale(0.97); transition: transform 0.1s ease; }
    .mobile-nav-item:active { transform: scale(0.9); transition: transform 0.1s ease; }
    .faq-question:active { background: var(--bg-light); }
    .feature-card:active,
    .character-card:active,
    .scenario-card:active,
    .testimonial-card:active,
    .comparison-card:active {
        transform: scale(0.98);
        transition: transform 0.1s ease;
    }
    .btn, .mobile-nav-item, .faq-question,
    .nav-toggle, .download-btn, .keywords-cloud a {
        min-height: 44px;
        min-width: 44px;
    }
    section[id], .section[id], .download-section[id] {
        scroll-margin-top: 60px;
    }
}

/* Small Mobile */
@media (max-width: 375px) {
    .characters-grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }
    .character-avatar { width: 56px; height: 56px; font-size: 1.2rem; }
    .character-card { padding: 18px 12px; }

    .mobile-nav-item { font-size: 0.66rem; padding: 4px 4px; }
    .mobile-nav-icon { font-size: 1.05rem; }
    .mobile-nav-download { padding: 4px 8px !important; }

    .hero-title { font-size: 1.4rem; }
    .hero-keywords { gap: 4px; }
    .hero-keywords span { font-size: 0.72rem; padding: 3px 10px; }
    .hero-showcase-img { max-width: 200px; }

    .container { padding: 0 14px; }
    .section-title { font-size: 1.25rem; }

    .download-qr { width: 120px; height: 120px; }

    .scenario-banner { height: 150px; }
}

/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
    :root {
        --text: #f1f5f9;
        --text-light: #cbd5e1;
        --text-muted: #94a3b8;
        --bg: #0f172a;
        --bg-light: #1e293b;
        --border: #334155;
        --border-light: #1e293b;
    }

    .site-header { background: rgba(15, 23, 42, 0.95); }
    .feature-card, .character-card, .scenario-card,
    .testimonial-card, .comparison-card, .tutorial-step,
    .download-card, .faq-item {
        background: #1e293b;
        border-color: #334155;
    }

    .faq-question:hover { background: #334155; }
    .keywords-cloud a { background: #1e293b; border-color: #334155; color: #cbd5e1; }
    .mobile-nav { background: #0f172a; }
}

/* Animation */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate {
    animation: fadeInUp 0.6s ease forwards;
}

/* Print */
@media print {
    .site-header, .mobile-nav, .fab-download, .site-footer { display: none; }
    body { padding: 0; }
}