:root {
    --bg-color: #FAFBFC;
    --text-color: #2C3E50;
    --text-secondary: #6B7280;
    --accent-color: #FF6B6B;
    --border-color: #E5E7EB;
    --sticker-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
    --sticker-shadow-hover: 0 12px 40px rgba(0, 0, 0, 0.18);
    --nav-height: 70px;
    --font-hand: 'Patrick Hand', cursive;
    --font-sans: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

:root[data-theme="dark"] {
    --bg-color: #0F172A;
    --text-color: #E2E8F0;
    --text-secondary: #94A3B8;
    --accent-color: #FF8787;
    --border-color: #334155;
    --sticker-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
    --sticker-shadow-hover: 0 12px 40px rgba(0, 0, 0, 0.6);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: calc(var(--nav-height) + 20px);
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    font-size: 16px;
    transition: background-color 0.3s, color 0.3s;
    overflow-x: hidden;
}

/* SVG Filter for Sticker Effect */
.sticker-svg {
    position: absolute;
    width: 0;
    height: 0;
    pointer-events: none;
}

/* Navigation - Non-Sticky Part (Logo + CTA) */
/* 这个类已废弃,保留代码以便将来需要 */

/* Navigation */
.sticker-nav {
    position: sticky;
    top: 0;
    height: var(--nav-height);
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 3px solid var(--accent-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 32px;
    z-index: 1000;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
}

:root[data-theme="dark"] .sticker-nav {
    background: rgba(15, 23, 42, 0.85);
}

.nav-logo-sticker {
    display: flex;
    align-items: center;
}

.nav-logo-sticker img {
    height: 45px;
    width: auto;
    transform: rotate(-3deg);
    transition: transform 0.3s ease;
}

.nav-logo-sticker:hover img {
    transform: rotate(3deg) scale(1.1);
}

.cta-button-sticker {
    padding: 12px 28px;
    background: var(--accent-color);
    color: white !important;
    text-decoration: none;
    font-weight: 700;
    font-size: 16px;
    border-radius: 25px;
    border: 3px solid #2C3E50;
    box-shadow: 5px 5px 0 #2C3E50;
    transition: all 0.2s ease;
}

.cta-button-sticker:hover {
    transform: translate(-3px, -3px);
    box-shadow: 7px 7px 0 #2C3E50;
}

.nav-links-sticker {
    display: flex;
    gap: 8px;
}

.nav-link-sticker {
    padding: 10px 20px;
    background: linear-gradient(135deg, #FFE66D 0%, #F7D794 100%);
    color: #2C3E50 !important;
    text-decoration: none;
    font-weight: 600;
    font-size: 15px;
    border-radius: 20px;
    border: 3px solid #2C3E50;
    box-shadow: 4px 4px 0 #2C3E50;
    transition: all 0.2s ease;
    position: relative;
}

.nav-link-sticker:hover {
    transform: translate(-2px, -2px);
    box-shadow: 6px 6px 0 #2C3E50;
}

/* Hero Section */
.hero-section {
    min-height: calc(100vh - var(--nav-height));
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 80px 24px;
    position: relative;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
    overflow: hidden;
}

:root[data-theme="dark"] .hero-section {
    background: linear-gradient(135deg, #1e3a5f 0%, #2d1b4e 100%);
}

@keyframes gradientShift {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image:
        radial-gradient(circle at 20% 50%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255, 255, 255, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    max-width: 800px;
    text-align: center;
    position: relative;
    z-index: 1;
}

.hero-badge-sticker {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background: #FFE66D;
    border: 3px solid #2C3E50;
    border-radius: 30px;
    box-shadow: 5px 5px 0 #2C3E50;
    margin-bottom: 32px;
    animation: bounceIn 0.8s ease;
    transform: rotate(-3deg);
    /* Remove tilt effect - keep static rotation */
    pointer-events: none !important;
}

.badge-icon {
    font-size: 24px;
}

img.badge-icon {
    width: 24px;
    height: 24px;
    object-fit: contain;
    display: inline-block;
    vertical-align: middle;
}

.badge-text {
    font-weight: 700;
    font-size: 16px;
    color: #2C3E50;
}

@keyframes bounceIn {
    0% {
        opacity: 0;
        transform: scale(0.3) rotate(-3deg);
    }
    50% {
        transform: scale(1.05) rotate(-3deg);
    }
    70% {
        transform: scale(0.9) rotate(-3deg);
    }
    100% {
        transform: scale(1) rotate(-3deg);
    }
}

.hero-title {
    font-family: var(--font-hand);
    font-size: 4.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 24px;
    color: white;
    text-shadow: 4px 4px 0 rgba(0, 0, 0, 0.2);
    animation: slideUp 0.8s ease 0.2s both;
}

.hero-title .highlight {
    color: #FFE66D;
    text-shadow: 4px 4px 0 rgba(0, 0, 0, 0.3);
    position: relative;
    display: inline-block;
}

.hero-title .highlight::after {
    content: '';
    position: absolute;
    bottom: 8px;
    left: 0;
    right: 0;
    height: 12px;
    background: rgba(255, 255, 255, 0.3);
    z-index: -1;
    transform: rotate(-1deg);
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-subtitle {
    font-size: 1.4rem;
    color: rgba(255, 255, 255, 0.95);
    margin-bottom: 48px;
    line-height: 1.8;
    animation: slideUp 0.8s ease 0.4s both;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
    animation: slideUp 0.8s ease 0.6s both;
}

.sticker-button {
    position: relative;
    padding: 18px 40px;
    font-size: 18px;
    font-weight: 700;
    text-decoration: none;
    border-radius: 30px;
    border: 3px solid #2C3E50;
    box-shadow: 6px 6px 0 #2C3E50;
    transition: all 0.2s ease;
    display: inline-block;
    transform-style: preserve-3d;
}

.primary-sticker {
    background: linear-gradient(135deg, #FFE66D 0%, #F7D794 100%);
    color: #2C3E50 !important;
}

.secondary-sticker {
    background: white;
    color: #2C3E50 !important;
}

.sticker-button:hover {
    transform: translate(-4px, -4px);
    box-shadow: 10px 10px 0 #2C3E50;
}

.button-text {
    position: relative;
    z-index: 1;
}

.button-shadow {
    position: absolute;
    top: 3px;
    left: 3px;
    right: -3px;
    bottom: -3px;
    background: #2C3E50;
    border-radius: 30px;
    z-index: 0;
    transition: all 0.2s ease;
}

/* Floating Stickers */
.floating-stickers {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
    overflow: hidden;
}

.sticker-item {
    position: absolute;
    font-size: 48px;
    animation: float 4s ease-in-out infinite;
    filter: drop-shadow(4px 4px 8px rgba(0, 0, 0, 0.2));
}

.sticker-item img.sticker-emoji {
    width: 48px;
    height: 48px;
    object-fit: contain;
    display: block;
}

.sticker-item:nth-child(1) {
    top: 10%;
    left: 8%;
    transform: rotate(var(--rotation));
}

.sticker-item:nth-child(2) {
    top: 20%;
    right: 10%;
    transform: rotate(var(--rotation));
}

.sticker-item:nth-child(3) {
    bottom: 15%;
    left: 12%;
    transform: rotate(var(--rotation));
}

.sticker-item:nth-child(4) {
    bottom: 25%;
    right: 8%;
    transform: rotate(var(--rotation));
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) rotate(var(--rotation));
    }
    50% {
        transform: translateY(-20px) rotate(var(--rotation));
    }
}

/* Features Section */
.features-section {
    padding: 100px 24px;
    background: var(--bg-color);
    position: relative;
}

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

.section-title-sticker {
    font-family: var(--font-hand);
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-color);
    position: relative;
    display: inline-block;
}

.section-title-sticker::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--accent-color);
    border-radius: 2px;
}

.section-subtitle-sticker {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-top: 16px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 32px;
    max-width: 1200px;
    margin: 0 auto;
}

.feature-sticker-card {
    background: var(--card-color);
    padding: 40px 32px;
    border-radius: 20px;
    border: 3px solid #2C3E50;
    box-shadow: 8px 8px 0 #2C3E50;
    transition: all 0.3s ease;
    text-align: center;
    position: relative;
    overflow: hidden;
    transform-style: preserve-3d;
}

:root[data-theme="dark"] .feature-sticker-card {
    border-color: #4A5568;
    box-shadow: 8px 8px 0 #4A5568;
}

:root[data-theme="dark"] .feature-sticker-card h3,
:root[data-theme="dark"] .feature-sticker-card p {
    color: #1A2332 !important;
}

.feature-sticker-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: var(--card-color);
    filter: brightness(0.9);
}

.feature-sticker-card:hover {
    transform: translateY(-8px) rotate(-1deg);
    box-shadow: 12px 12px 0 #2C3E50;
}

:root[data-theme="dark"] .feature-sticker-card:hover {
    box-shadow: 12px 12px 0 #4A5568;
}

.sticker-icon {
    font-size: 64px;
    margin-bottom: 20px;
    display: block;
}

.sticker-icon-img {
    width: 64px;
    height: 64px;
    object-fit: contain;
}

.feature-sticker-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-color);
}

.feature-sticker-card p {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* How It Works Section */
.how-it-works-section {
    padding: 100px 24px;
    background: linear-gradient(135deg, #f5f7fa 0%, #e8ecf3 100%);
}

:root[data-theme="dark"] .how-it-works-section {
    background: linear-gradient(135deg, #1a2332 0%, #0f172a 100%);
}

.steps-timeline {
    max-width: 900px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 40px;
}

.step-sticker {
    background: white;
    border-radius: 20px;
    padding: 32px;
    border: 3px solid #2C3E50;
    box-shadow: 6px 6px 0 var(--step-color);
    position: relative;
    transition: all 0.3s ease;
    transform-style: preserve-3d;
}

:root[data-theme="dark"] .step-sticker {
    background: #1E293B;
    border-color: #4A5568;
}

.step-sticker:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: 10px 10px 0 var(--step-color);
}

.step-number-sticker {
    position: absolute;
    top: -16px;
    left: 24px;
    width: 48px;
    height: 48px;
    background: var(--step-color);
    color: white;
    border: 3px solid #2C3E50;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: 700;
    font-family: var(--font-hand);
    box-shadow: 3px 3px 0 #2C3E50;
}

:root[data-theme="dark"] .step-number-sticker {
    border-color: #4A5568;
    box-shadow: 3px 3px 0 #4A5568;
}

.step-content-sticker {
    margin-top: 16px;
}

.step-content-sticker h3 {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-color);
}

.step-content-sticker p {
    color: var(--text-secondary);
    line-height: 1.7;
}

.step-emoji {
    position: absolute;
    bottom: 16px;
    right: 16px;
    font-size: 40px;
    opacity: 0.3;
}

.step-emoji-icon {
    width: 40px;
    height: 40px;
    object-fit: contain;
}

/* Video Section */
.video-section {
    padding: 100px 24px;
    background: var(--bg-color);
}

.video-sticker-container {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
}

.video-badge-sticker {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: #FFE66D;
    border: 3px solid #2C3E50;
    border-radius: 25px;
    box-shadow: 4px 4px 0 #2C3E50;
    margin-bottom: 24px;
    position: absolute;
    top: -20px;
    left: 50%;
    transform: translateX(-50%) rotate(-2deg);
    z-index: 10;
}

.badge-emoji {
    font-size: 20px;
}

img.badge-emoji {
    width: 40px;
    height: 40px;
    object-fit: contain;
    display: inline-block;
    vertical-align: middle;
}

.badge-text {
    font-weight: 700;
    font-size: 14px;
    color: #2C3E50;
}

.video-wrapper-sticker {
    border-radius: 20px;
    overflow: hidden;
    border: 4px solid #2C3E50;
    box-shadow: 10px 10px 0 #2C3E50;
    background: #000;
    aspect-ratio: 16/9;
}

:root[data-theme="dark"] .video-wrapper-sticker {
    border-color: #4A5568;
    box-shadow: 10px 10px 0 #4A5568;
}

.video-wrapper-sticker iframe {
    width: 100%;
    height: 100%;
}

/* Video Cover */
.video-cover {
    position: relative;
    width: 100%;
    height: 100%;
    cursor: pointer;
    overflow: hidden;
}

.cover-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.video-cover:hover .cover-image {
    transform: scale(1.05);
}

.play-button {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 80px;
    height: 80px;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
}

.video-cover:hover .play-button {
    transform: translate(-50%, -50%) scale(1.1);
    background: rgba(255, 255, 255, 1);
}

.play-icon {
    width: 32px;
    height: 32px;
    margin-left: 4px; /* Visually center the play triangle */
}

:root[data-theme="dark"] .play-button {
    background: rgba(0, 0, 0, 0.8);
}

/* Privacy Section */
.privacy-section {
    padding: 100px 24px;
    background: linear-gradient(135deg, #ffecd2 0%, #fcb69f 100%);
}

:root[data-theme="dark"] .privacy-section {
    background: linear-gradient(135deg, #2d3748 0%, #1a202c 100%);
}

.privacy-card-stack {
    max-width: 600px;
    margin: 0 auto;
    position: relative;
    height: 500px;
}

.privacy-sticker-card {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    background: white;
    padding: 28px;
    border-radius: 20px;
    border: 4px solid #2C3E50;
    box-shadow: 10px 10px 0 #2C3E50;
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    overflow: hidden;
    height: 510px;
    display: flex;
    flex-direction: column;
    pointer-events: auto;
}

:root[data-theme="dark"] .privacy-sticker-card {
    background: #1E293B;
    border-color: #4A5568;
    box-shadow: 10px 10px 0 #4A5568;
}

/* 卡片堆叠效果 - 后面的卡片 */
.privacy-sticker-card:not(.active) {
    transform: translate(20px, 20px) rotate(2deg);
    opacity: 0.6;
    z-index: 1;
}

/* 激活的卡片 - 前面 */
.privacy-sticker-card.active {
    transform: translate(0, 0) rotate(0deg);
    opacity: 1;
    z-index: 2;
}

.privacy-sticker-card:hover {
    box-shadow: 12px 12px 0 #2C3E50;
}

:root[data-theme="dark"] .privacy-sticker-card:hover {
    box-shadow: 12px 12px 0 #4A5568;
}

/* 切换提示 */
.card-toggle-hint {
    position: absolute;
    top: 16px;
    right: 16px;
    background: #FFE66D;
    color: #2C3E50;
    padding: 6px 12px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
    border: 2px solid #2C3E50;
    box-shadow: 2px 2px 0 #2C3E50;
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: 10;
    pointer-events: none;
}

/* 鼠标悬停在任何卡片上时,两个卡片的提示都显示 */
.privacy-card-stack:hover .card-toggle-hint {
    opacity: 1;
}

.privacy-icon-sticker {
    font-size: 36px;
    margin-bottom: 8px;
    display: block;
    text-align: center;
    flex-shrink: 0;
}

.privacy-icon-image {
    width: 64px;
    height: 64px;
    object-fit: contain;
    display: inline-block;
}

.privacy-sticker-card h2 {
    font-family: var(--font-hand);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-color);
    text-align: center;
    flex-shrink: 0;
}

.privacy-points {
    text-align: left;
    margin-bottom: 12px;
    flex: 1;
    overflow-y: auto;
    padding-right: 4px;
}

.privacy-point {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 10px;
    background: var(--bg-color);
    border-radius: 10px;
    margin-bottom: 8px;
    border: 2px solid var(--border-color);
    transition: all 0.2s ease;
    pointer-events: auto;
}

.privacy-point:hover {
    background: var(--card-bg);
    transform: translateX(3px);
}

.point-check {
    flex-shrink: 0;
    width: 20px;
    height: 20px;
    background: #10B981;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 11px;
}

.privacy-point-content h4 {
    font-size: 0.9rem;
    font-weight: 700;
    margin: 0 0 4px 0;
    color: var(--text-color);
}

.privacy-point-content p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 0.8rem;
    line-height: 1.3;
}

.privacy-contact {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.8rem;
    flex-shrink: 0;
}

.privacy-contact a {
    color: var(--accent-color);
    font-weight: 600;
}

/* Attribution List */
.attribution-list {
    margin-bottom: 12px;
    flex: 1;
    overflow-y: auto;
    padding-right: 4px;
}

.attribution-item {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 10px;
    background: var(--bg-color);
    border-radius: 10px;
    margin-bottom: 8px;
    border: 2px solid var(--border-color);
    transition: all 0.2s ease;
    pointer-events: auto;
}

.attribution-item:hover {
    background: var(--card-bg);
    transform: translateX(3px);
}

.attribution-content h4 {
    font-size: 0.9rem;
    font-weight: 700;
    margin: 0 0 4px 0;
    color: var(--text-color);
}

.attribution-content p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 0.8rem;
    line-height: 1.3;
}

.privacy-note {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.75rem;
    font-style: italic;
    margin: 0;
    flex-shrink: 0;
}

/* CTA Section */
.cta-section {
    padding: 100px 24px;
    background: var(--bg-color);
    text-align: center;
}

:root[data-theme="dark"] .cta-section {
    background: #1A1F3A;
}

.cta-sticker-box {
    max-width: 700px;
    margin: 0 auto;
    padding: 60px 40px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 30px;
    border: 4px solid #2C3E50;
    box-shadow: 12px 12px 0 #2C3E50;
    color: white;
}

:root[data-theme="dark"] .cta-sticker-box {
    border-color: #4A5568;
    box-shadow: 12px 12px 0 #4A5568;
}

.cta-sticker-box h2 {
    font-family: var(--font-hand);
    font-size: 2.8rem;
    font-weight: 700;
    margin-bottom: 16px;
    text-shadow: 3px 3px 0 rgba(0, 0, 0, 0.2);
}

.cta-sticker-box p {
    font-size: 1.3rem;
    margin-bottom: 32px;
    opacity: 0.95;
}

.cta-large-sticker {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 20px 48px;
    background: #FFE66D;
    color: #2C3E50 !important;
    text-decoration: none;
    font-size: 20px;
    font-weight: 700;
    border-radius: 30px;
    border: 3px solid #2C3E50;
    box-shadow: 6px 6px 0 #2C3E50;
    transition: all 0.2s ease;
    transform-style: preserve-3d;
}

.cta-large-sticker:hover {
    transform: translate(-4px, -4px);
    box-shadow: 10px 10px 0 #2C3E50;
}

.cta-text {
    position: relative;
    z-index: 1;
}

.cta-arrow {
    font-size: 24px;
    transition: transform 0.3s ease;
}

.cta-large-sticker:hover .cta-arrow {
    transform: translateX(5px);
}

/* Responsive Design */
@media (max-width: 768px) {
    /* 移动端隐藏CTA按钮 */
    .sticker-nav .cta-button-sticker {
        display: none;
    }

    .sticker-nav {
        padding: 8px 12px;
        height: 50px;
        min-height: 50px;
        flex-wrap: nowrap;
        gap: 0;
        justify-content: space-between;
    }

    /* 在移动端显示logo */
    .sticker-nav .nav-logo-sticker {
        display: flex;
        flex-shrink: 0;
    }

    .sticker-nav .nav-logo-sticker img {
        height: 36px;
        width: auto;
    }

    .nav-links-sticker {
        display: flex;
        flex-wrap: nowrap;
        gap: 4px;
        justify-content: center;
        align-items: center;
    }

    .nav-link-sticker {
        padding: 5px 10px;
        font-size: 12px;
        border-width: 2px;
        box-shadow: 2px 2px 0 #2C3E50;
        white-space: nowrap;
    }

    .nav-link-sticker:hover {
        box-shadow: 3px 3px 0 #2C3E50;
    }

    .video-badge-sticker {
        top: -18px;
        padding: 6px 12px;
        gap: 6px;
        white-space: nowrap;
        max-width: 90%;
    }

    .video-badge-sticker .badge-emoji {
        font-size: 16px;
    }

    .video-badge-sticker img.badge-emoji {
        width: 24px;
        height: 24px;
    }

    .video-badge-sticker .badge-text {
        font-size: 12px;
    }

    .hero-title {
        font-size: 3rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .sticker-button {
        width: 100%;
        max-width: 300px;
    }

    .floating-stickers {
        display: none;
    }

    .section-title-sticker {
        font-size: 2.2rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .steps-timeline {
        grid-template-columns: 1fr;
    }

    .privacy-card-stack {
        height: 450px;
    }

    .privacy-sticker-card {
        padding: 24px 20px;
        height: 450px;
    }

    .privacy-sticker-card:not(.active) {
        transform: translate(12px, 12px) rotate(2deg);
    }

    .cta-sticker-box {
        padding: 40px 24px;
    }

    .cta-sticker-box h2 {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2.2rem;
    }

    .section-title-sticker {
        font-size: 1.8rem;
    }

    .feature-sticker-card,
    .step-sticker {
        padding: 24px;
    }

    .faq-section {
        padding: 60px 20px;
    }

    .faq-question {
        padding: 16px 20px;
        font-size: 1rem;
    }

    .faq-answer {
        padding: 0 20px 20px 20px !important;
    }

    /* 进一步优化小屏幕的video badge */
    .video-badge-sticker {
        padding: 5px 10px;
        gap: 4px;
    }

    .video-badge-sticker img.badge-emoji {
        width: 20px;
        height: 20px;
    }

    .video-badge-sticker .badge-text {
        font-size: 11px;
    }
}

/* Smooth Scroll Behavior */
html {
    scroll-behavior: smooth;
}

/* Selection Color */
::selection {
    background: var(--accent-color);
    color: white;
}

::-moz-selection {
    background: var(--accent-color);
    color: white;
}

/* Focus Styles */
a:focus,
button:focus {
    outline: 3px solid var(--accent-color);
    outline-offset: 3px;
}

/* FAQ Section */
.faq-section {
    padding: 100px 24px;
    background: var(--bg-color);
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-top: 40px;
}

.faq-item {
    background: white;
    border-radius: 16px;
    border: 3px solid #2C3E50;
    box-shadow: 6px 6px 0 #2C3E50;
    transition: all 0.3s ease;
    overflow: hidden;
    cursor: pointer;
}

:root[data-theme="dark"] .faq-item {
    background: #1E293B;
    border-color: #4A5568;
    box-shadow: 6px 6px 0 #4A5568;
}

.faq-item:hover {
    transform: translateY(-3px);
    box-shadow: 8px 8px 0 #2C3E50;
}

:root[data-theme="dark"] .faq-item:hover {
    box-shadow: 8px 8px 0 #4A5568;
}

.faq-question {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 20px 24px;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-color);
    cursor: pointer;
    user-select: none;
    list-style: none;
    position: relative;
}

.faq-question::-webkit-details-marker {
    display: none;
}

.faq-question::after {
    content: '+';
    position: absolute;
    right: 24px;
    font-size: 24px;
    font-weight: 700;
    color: var(--accent-color);
    transition: transform 0.3s ease;
}

.faq-item[open] .faq-question::after {
    transform: rotate(45deg);
}

.faq-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: var(--accent-color);
    color: white;
    border-radius: 50%;
    font-size: 0.85rem;
    font-weight: 700;
    flex-shrink: 0;
    border: 2px solid #2C3E50;
}

.faq-answer {
    padding: 0 24px 24px 76px;
}

.faq-answer p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.6;
}