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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f7fa;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    color: #fff;
    padding: 20px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo h1 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 2px;
    background: linear-gradient(90deg, #00d4ff, #7c3aed);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo p {
    font-size: 0.85rem;
    opacity: 0.8;
}

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

.nav-links a {
    color: #fff;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
}

.nav-links a:hover,
.nav-links a.active {
    color: #00d4ff;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: #00d4ff;
    transition: width 0.3s ease;
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

.hero {
    padding: 80px 0;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    color: #fff;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-content h2 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 30px;
}

.hero-buttons {
    display: flex;
    gap: 20px;
}

.btn {
    padding: 12px 30px;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary {
    background: linear-gradient(90deg, #00d4ff, #7c3aed);
    color: #fff;
    border: none;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(0, 212, 255, 0.4);
}

.btn-secondary {
    background: transparent;
    color: #00d4ff;
    border: 2px solid #00d4ff;
}

.btn-secondary:hover {
    background: rgba(0, 212, 255, 0.1);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: #333;
    border: 2px solid #333;
}

.btn-outline:hover {
    background: #333;
    color: #fff;
}

.demo-box {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    padding: 20px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.video-preview {
    background: #000;
    border-radius: 12px;
    overflow: hidden;
}

.frame-content {
    height: 300px;
    background: linear-gradient(135deg, #2d3436, #636e72);
    position: relative;
    overflow: hidden;
}

.detection-box {
    position: absolute;
    border: 2px solid #00d4ff;
    background: rgba(0, 212, 255, 0.1);
    cursor: pointer;
    transition: all 0.3s ease;
}

.detection-box:hover {
    background: rgba(0, 212, 255, 0.2);
    border-color: #7c3aed;
}

.detection-box span {
    position: absolute;
    top: -25px;
    left: 0;
    background: #00d4ff;
    color: #000;
    padding: 2px 8px;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 4px;
}

.detection-box .confidence {
    position: absolute;
    bottom: -20px;
    right: 0;
    background: rgba(124, 58, 237, 0.9);
    color: #fff;
    padding: 2px 6px;
    font-size: 0.7rem;
    border-radius: 4px;
}

.video-controls {
    padding: 15px;
    background: rgba(0, 0, 0, 0.5);
}

.progress-bar {
    height: 6px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 3px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #00d4ff, #7c3aed);
    width: 35%;
    border-radius: 3px;
}

.features {
    padding: 80px 0;
    background: #fff;
}

.features h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 60px;
    color: #1a1a2e;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.feature-card {
    background: #f8fafc;
    border-radius: 16px;
    padding: 35px;
    transition: all 0.3s ease;
    border: 1px solid #e2e8f0;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    border-color: #00d4ff;
}

.feature-icon {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    font-size: 1.5rem;
}

.feature-icon.object-detection {
    background: linear-gradient(135deg, #00d4ff, #06b6d4);
    color: #fff;
}

.feature-icon.face-recognition {
    background: linear-gradient(135deg, #7c3aed, #8b5cf6);
    color: #fff;
}

.feature-icon.frame-zoom {
    background: linear-gradient(135deg, #f59e0b, #f97316);
    color: #fff;
}

.feature-icon.video-nav {
    background: linear-gradient(135deg, #10b981, #059669);
    color: #fff;
}

.feature-card h3 {
    font-size: 1.4rem;
    margin-bottom: 15px;
    color: #1a1a2e;
}

.feature-card p {
    color: #64748b;
    margin-bottom: 20px;
    line-height: 1.7;
}

.feature-card ul {
    list-style: none;
}

.feature-card li {
    padding: 8px 0;
    padding-left: 25px;
    position: relative;
    color: #475569;
}

.feature-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: #00d4ff;
    font-weight: bold;
}

.workflow {
    padding: 80px 0;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    color: #fff;
}

.workflow h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 60px;
}

.steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.step {
    text-align: center;
}

.step-number {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: linear-gradient(90deg, #00d4ff, #7c3aed);
    color: #fff;
    font-size: 1.5rem;
    font-weight: bold;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
}

.step h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.step p {
    opacity: 0.8;
    font-size: 0.95rem;
}

.screenshots {
    padding: 80px 0;
    background: #fff;
}

.screenshots h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: #1a1a2e;
}

.screenshots-desc {
    text-align: center;
    color: #64748b;
    font-size: 1.1rem;
    margin-bottom: 50px;
}

.screenshots-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    margin-bottom: 40px;
}

.screenshot-item {
    background: #f8fafc;
    border-radius: 16px;
    padding: 25px;
    border: 1px solid #e2e8f0;
    transition: all 0.3s ease;
}

.screenshot-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.screenshot-wrapper {
    position: relative;
    width: 100%;
    aspect-ratio: 16 / 9;
    background: linear-gradient(135deg, #1a1a2e, #16213e);
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 20px;
}

.screenshot-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    cursor: pointer;
}

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

.placeholder-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
    color: rgba(255, 255, 255, 0.6);
}

.placeholder-content svg {
    width: 60px;
    height: 60px;
    opacity: 0.5;
}

.placeholder-content span {
    font-size: 0.9rem;
    font-weight: 500;
}

.screenshot-item h4 {
    font-size: 1.2rem;
    color: #1a1a2e;
    margin-bottom: 8px;
}

.screenshot-item p {
    color: #64748b;
    font-size: 0.95rem;
}

.screenshots-note {
    text-align: center;
    padding: 20px;
    background: #fef3c7;
    border-radius: 12px;
    border-left: 4px solid #f59e0b;
}

.screenshots-note p {
    color: #92400e;
    font-size: 0.9rem;
}

.screenshots-note code {
    background: #fcd34d;
    padding: 3px 8px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.85rem;
}

.screenshot-section {
    padding: 60px 0;
    background: linear-gradient(135deg, #f8fafc, #f1f5f9);
}

.screenshot-display {
    display: grid;
    grid-template-columns: 3fr 1fr;
    gap: 30px;
}

.screenshot-wrapper-large {
    background: #fff;
    border-radius: 16px;
    padding: 15px;
    border: 1px solid #e2e8f0;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
}

.screenshot-placeholder-large {
    width: 100%;
    aspect-ratio: 16 / 9;
    background: linear-gradient(135deg, #1a1a2e, #16213e);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    cursor: pointer;
    overflow: hidden;
}

.screenshot-placeholder-large img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 12px;
}

.screenshot-placeholder-large .placeholder-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    color: rgba(255, 255, 255, 0.6);
}

.screenshot-placeholder-large .placeholder-content svg {
    width: 80px;
    height: 80px;
    opacity: 0.4;
}

.screenshot-placeholder-large .placeholder-content span {
    font-size: 1.2rem;
    font-weight: 500;
}

.screenshot-placeholder-large .placeholder-content small {
    font-size: 0.85rem;
    opacity: 0.5;
    color: rgba(255, 255, 255, 0.4);
}

.screenshot-annotations {
    background: #fff;
    border-radius: 16px;
    padding: 20px;
    border: 1px solid #e2e8f0;
}

.annotation-item {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 12px 0;
    border-bottom: 1px solid #f1f5f9;
}

.annotation-item:last-child {
    border-bottom: none;
}

.annotation-num {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: linear-gradient(135deg, #00d4ff, #7c3aed);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.9rem;
}

.annotation-text {
    color: #475569;
    font-size: 0.95rem;
    line-height: 1.4;
}

.usage-guide {
    padding: 60px 0;
    background: #fff;
}

.usage-guide h2 {
    text-align: center;
    font-size: 2.2rem;
    margin-bottom: 40px;
    color: #1a1a2e;
}

.guide-sections {
    display: grid;
    gap: 40px;
}

.guide-section {
    background: #f8fafc;
    border-radius: 16px;
    padding: 30px;
    border: 1px solid #e2e8f0;
}

.guide-section h3 {
    font-size: 1.4rem;
    margin-bottom: 25px;
    color: #1a1a2e;
    display: flex;
    align-items: center;
    gap: 10px;
}

.guide-steps {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 25px;
}

.guide-step {
    background: #fff;
    border-radius: 12px;
    padding: 20px;
    border: 1px solid #e2e8f0;
}

.step-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.step-icon {
    font-size: 1.5rem;
}

.step-header h4 {
    font-size: 1.1rem;
    color: #1a1a2e;
}

.guide-step p {
    color: #64748b;
    line-height: 1.6;
    font-size: 0.95rem;
}

.guide-controls {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 20px;
}

.control-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    background: #fff;
    border-radius: 12px;
    padding: 20px 15px;
    border: 1px solid #e2e8f0;
}

.control-btn-demo {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: #f1f5f9;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 15px;
    color: #475569;
}

.control-btn-demo svg {
    width: 24px;
    height: 24px;
}

.control-btn-demo.play {
    background: linear-gradient(135deg, #00d4ff, #7c3aed);
    color: #fff;
    width: 60px;
    height: 60px;
}

.control-info h4 {
    font-size: 1rem;
    color: #1a1a2e;
    margin-bottom: 8px;
}

.control-info p {
    color: #64748b;
    font-size: 0.85rem;
}

.speed-selector {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 15px;
    margin-bottom: 20px;
}

.speed-item {
    background: #fff;
    border-radius: 10px;
    padding: 15px;
    text-align: center;
    border: 1px solid #e2e8f0;
    transition: all 0.3s ease;
}

.speed-item:hover {
    border-color: #00d4ff;
    transform: translateY(-2px);
}

.speed-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: #00d4ff;
    margin-bottom: 8px;
    display: block;
}

.speed-desc {
    color: #64748b;
    font-size: 0.85rem;
}

.guide-note {
    color: #64748b;
    font-size: 0.95rem;
    background: #fef3c7;
    padding: 15px;
    border-radius: 8px;
    border-left: 4px solid #f59e0b;
}

.info-display {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.info-item {
    background: #fff;
    border-radius: 12px;
    padding: 20px;
    text-align: center;
    border: 1px solid #e2e8f0;
}

.info-label {
    color: #64748b;
    font-size: 0.9rem;
    margin-bottom: 8px;
    display: block;
}

.info-value {
    font-size: 1.4rem;
    font-weight: 700;
    color: #00d4ff;
    margin-bottom: 8px;
    display: block;
}

.info-note {
    color: #94a3b8;
    font-size: 0.8rem;
}

.guide-results {
    display: grid;
    gap: 20px;
}

.result-demo {
    display: flex;
    align-items: center;
    gap: 20px;
    background: #fff;
    border-radius: 12px;
    padding: 20px;
    border: 1px solid #e2e8f0;
}

.result-thumb-demo {
    width: 60px;
    height: 60px;
    border-radius: 10px;
    background: linear-gradient(135deg, #f1f5f9, #e2e8f0);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #475569;
}

.result-thumb-demo svg {
    width: 32px;
    height: 32px;
}

.result-info h4 {
    font-size: 1.1rem;
    color: #1a1a2e;
    margin-bottom: 8px;
}

.result-info p {
    color: #64748b;
    font-size: 0.95rem;
}

.range-control-demo {
    margin-bottom: 25px;
}

.range-slider-demo {
    padding: 20px 0;
}

.range-track {
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    position: relative;
}

.range-fill-middle {
    position: absolute;
    left: 20%;
    width: 60%;
    height: 100%;
    background: linear-gradient(90deg, #00d4ff, #7c3aed);
    border-radius: 4px;
}

.range-thumb-min,
.range-thumb-max {
    position: absolute;
    width: 16px;
    height: 24px;
    background: #fff;
    border: 2px solid #00d4ff;
    border-radius: 4px;
    top: -8px;
}

.range-thumb-min {
    left: 20%;
}

.range-thumb-max {
    left: 80%;
}

.range-desc p {
    color: #64748b;
    font-size: 0.95rem;
    background: #fef3c7;
    padding: 15px;
    border-radius: 8px;
}

.progress-info {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.progress-item {
    background: #fff;
    border-radius: 12px;
    padding: 15px;
    text-align: center;
    border: 1px solid #e2e8f0;
}

.progress-label {
    font-weight: 600;
    color: #1a1a2e;
    margin-bottom: 8px;
    display: block;
}

.progress-desc {
    color: #64748b;
    font-size: 0.85rem;
}

.toolbar-demo {
    display: flex;
    justify-content: center;
    gap: 30px;
}

.toolbar-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.toolbar-btn-demo {
    width: 50px;
    height: 50px;
    border-radius: 12px;
    background: #f1f5f9;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #475569;
    margin-bottom: 10px;
    transition: all 0.3s ease;
}

.toolbar-btn-demo:hover {
    background: #00d4ff;
    color: #fff;
}

.toolbar-btn-demo svg {
    width: 24px;
    height: 24px;
}

.toolbar-name {
    color: #475569;
    font-size: 0.85rem;
}

.face-rec-settings {
    display: grid;
    gap: 20px;
}

.face-rec-item {
    display: flex;
    align-items: center;
    gap: 20px;
    background: #fff;
    border-radius: 12px;
    padding: 20px;
    border: 1px solid #e2e8f0;
}

.switch-demo {
    width: 50px;
    height: 26px;
    border-radius: 13px;
    background: #f1f5f9;
    position: relative;
}

.switch-track.on {
    background: #10b981;
}

.switch-thumb {
    position: absolute;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: #fff;
    top: 2px;
    left: 2px;
}

.switch-thumb.on {
    left: 26px;
}

.slider-demo {
    width: 200px;
}

.slider-track {
    height: 6px;
    background: #e2e8f0;
    border-radius: 3px;
    position: relative;
}

.slider-fill {
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    background: linear-gradient(90deg, #00d4ff, #7c3aed);
    border-radius: 3px;
}

.slider-thumb {
    position: absolute;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: #fff;
    border: 2px solid #00d4ff;
    top: -5px;
    transform: translateX(-50%);
}

.face-rec-label {
    font-weight: 600;
    color: #1a1a2e;
}

.face-rec-desc {
    color: #64748b;
    font-size: 0.85rem;
    flex: 1;
}

.feature-demo {
    padding: 80px 0;
    background: #fff;
}

.demo h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 60px;
    color: #1a1a2e;
}

.demo-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.demo-item {
    background: #f8fafc;
    border-radius: 16px;
    padding: 35px;
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid #e2e8f0;
}

.demo-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.demo-thumb {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: linear-gradient(135deg, #00d4ff, #7c3aed);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
}

.demo-icon {
    width: 50px;
    height: 50px;
    color: #fff;
}

.demo-item h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
    color: #1a1a2e;
}

.demo-item p {
    color: #64748b;
    margin-bottom: 25px;
}

.nav-download {
    background: linear-gradient(90deg, #00d4ff, #7c3aed);
    color: #fff;
    padding: 8px 20px;
    border-radius: 20px;
    font-weight: 600;
}

.nav-download:hover {
    transform: translateY(-2px);
    box-shadow: 0 2px 10px rgba(0, 212, 255, 0.4);
}

.download {
    padding: 80px 0;
    background: linear-gradient(135deg, #f0f9ff, #e0f2fe);
}

.download h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: #1a1a2e;
}

.download-desc {
    text-align: center;
    color: #64748b;
    font-size: 1.2rem;
    margin-bottom: 50px;
}

.download-info {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-bottom: 40px;
}

.version-info {
    background: #fff;
    border-radius: 16px;
    padding: 30px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border: 1px solid #e2e8f0;
}

.version-label {
    font-size: 0.9rem;
    color: #64748b;
    margin-bottom: 10px;
}

.version-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: #1a1a2e;
    margin-bottom: 15px;
}

.release-date {
    font-size: 0.85rem;
    color: #94a3b8;
}

.system-requirements {
    background: #fff;
    border-radius: 16px;
    padding: 30px;
    border: 1px solid #e2e8f0;
}

.system-requirements h4 {
    font-size: 1.2rem;
    color: #1a1a2e;
    margin-bottom: 20px;
}

.system-requirements ul {
    list-style: none;
}

.system-requirements li {
    padding: 8px 0;
    color: #475569;
    display: flex;
    align-items: center;
    gap: 10px;
}

.system-requirements li::before {
    content: '•';
    color: #00d4ff;
    font-size: 1.5rem;
}

.download-buttons {
    text-align: center;
    margin-bottom: 50px;
}

.btn-download {
    display: inline-flex;
    align-items: center;
    gap: 15px;
    padding: 20px 40px;
    background: linear-gradient(90deg, #00d4ff, #7c3aed);
    color: #fff;
    border-radius: 12px;
    font-size: 1.2rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    box-shadow: 0 5px 20px rgba(0, 212, 255, 0.3);
}

.btn-download:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0, 212, 255, 0.4);
}

.btn-download svg {
    width: 24px;
    height: 24px;
}

.download-note {
    margin-top: 20px;
    color: #64748b;
    font-size: 0.9rem;
}

.download-features {
    display: flex;
    justify-content: center;
    gap: 50px;
}

.download-feature {
    display: flex;
    align-items: center;
    gap: 15px;
    color: #475569;
}

.download-feature svg {
    width: 28px;
    height: 28px;
    color: #10b981;
}

.download-feature span {
    font-weight: 500;
}

footer {
    background: #1a1a2e;
    color: #fff;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h4 {
    margin-bottom: 20px;
    color: #00d4ff;
}

.footer-section p {
    opacity: 0.8;
    margin-bottom: 10px;
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: 10px;
}

.footer-section a {
    color: #fff;
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.3s ease;
}

.footer-section a:hover {
    opacity: 1;
    color: #00d4ff;
}

.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    opacity: 0.6;
}

.page-header {
    padding: 60px 0;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    color: #fff;
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
}

.page-header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

.feature-demo {
    padding: 60px 0;
    background: #fff;
}

.demo-layout {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 40px;
}

.viewer-section {
    background: #f8fafc;
    border-radius: 16px;
    padding: 30px;
    border: 1px solid #e2e8f0;
}

.viewer-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.viewer-header h3 {
    font-size: 1.3rem;
    color: #1a1a2e;
}

.zoom-controls {
    display: flex;
    align-items: center;
    gap: 10px;
}

.zoom-btn {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    background: #fff;
    border: 1px solid #e2e8f0;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    color: #333;
}

.zoom-btn:hover {
    background: #00d4ff;
    color: #fff;
    border-color: #00d4ff;
}

.zoom-level {
    font-weight: 600;
    min-width: 60px;
    text-align: center;
}

.frame-viewer {
    height: 400px;
    background: #000;
    border-radius: 12px;
    overflow: hidden;
    position: relative;
    cursor: grab;
}

.frame-viewer:active {
    cursor: grabbing;
}

.frame-viewer .frame-content {
    height: 100%;
    background: linear-gradient(135deg, #2d3436, #636e72);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.2s ease;
}

.frame-viewer .frame-content::before {
    content: '视频帧预览区域';
    color: rgba(255, 255, 255, 0.5);
    font-size: 1.2rem;
}

.viewer-footer {
    margin-top: 20px;
    padding-top: 15px;
    border-top: 1px solid #e2e8f0;
}

.frame-info {
    display: flex;
    gap: 30px;
    color: #64748b;
}

.nav-controls {
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: #fff;
    border: 1px solid #e2e8f0;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    color: #333;
}

.nav-btn:hover {
    background: #00d4ff;
    color: #fff;
    border-color: #00d4ff;
}

.play-btn {
    width: 50px;
    height: 50px;
    background: linear-gradient(90deg, #00d4ff, #7c3aed);
    color: #fff;
    border: none;
}

.play-btn:hover {
    transform: scale(1.05);
}

.timeline-section {
    margin-top: 25px;
}

.timeline-header {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    margin-bottom: 15px;
}

.time-display {
    font-family: 'Courier New', monospace;
    font-size: 1.2rem;
    font-weight: 600;
    color: #1a1a2e;
}

.time-divider {
    opacity: 0.5;
}

.timeline-container {
    background: #fff;
    border-radius: 8px;
    padding: 15px;
    border: 1px solid #e2e8f0;
}

.timeline-track {
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    position: relative;
    cursor: pointer;
    overflow: visible;
}

.timeline-progress {
    height: 100%;
    background: linear-gradient(90deg, #00d4ff, #7c3aed);
    border-radius: 4px;
    position: absolute;
    left: 0;
    top: 0;
}

.timeline-marker {
    width: 16px;
    height: 16px;
    background: #fff;
    border: 3px solid #00d4ff;
    border-radius: 50%;
    position: absolute;
    top: 50%;
    transform: translate(-50%, -50%);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

.timeline-keyframes {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
}

.keyframe {
    position: absolute;
    width: 10px;
    height: 10px;
    background: #7c3aed;
    border-radius: 50%;
    top: 50%;
    transform: translateY(-50%);
    cursor: pointer;
    transition: transform 0.2s ease;
}

.keyframe:hover {
    transform: translateY(-50%) scale(1.5);
}

.keyframe[data-frame="1500"] { left: 13.89%; }
.keyframe[data-frame="3200"] { left: 29.63%; }
.keyframe[data-frame="5800"] { left: 53.70%; }
.keyframe[data-frame="8900"] { left: 82.41%; }

.frame-input {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-top: 15px;
}

.frame-input label {
    color: #64748b;
    font-weight: 500;
}

.frame-input input {
    width: 100px;
    padding: 8px 12px;
    border: 1px solid #e2e8f0;
    border-radius: 6px;
    font-size: 1rem;
}

.frame-input button {
    padding: 8px 20px;
    background: linear-gradient(90deg, #00d4ff, #7c3aed);
    color: #fff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s ease;
}

.frame-input button:hover {
    transform: translateY(-2px);
}

.detail-section h3 {
    font-size: 1.4rem;
    margin-bottom: 25px;
    color: #1a1a2e;
}

.feature-list {
    margin-bottom: 25px;
}

.feature-item {
    display: flex;
    gap: 15px;
    padding: 20px;
    background: #f8fafc;
    border-radius: 12px;
    margin-bottom: 15px;
    border: 1px solid #e2e8f0;
}

.feature-icon-small {
    width: 45px;
    height: 45px;
    border-radius: 10px;
    background: linear-gradient(135deg, #00d4ff, #7c3aed);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    flex-shrink: 0;
}

.feature-text h4 {
    font-size: 1.1rem;
    margin-bottom: 5px;
    color: #1a1a2e;
}

.feature-text p {
    font-size: 0.95rem;
    color: #64748b;
    line-height: 1.6;
}

.tips-box {
    background: linear-gradient(135deg, #fff3e0, #ffe0b2);
    border-left: 4px solid #ff9800;
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 25px;
}

.tips-box h4 {
    color: #e65100;
    margin-bottom: 10px;
}

.tips-box ul {
    list-style: none;
}

.tips-box li {
    padding: 8px 0;
    color: #5d4037;
    font-size: 0.95rem;
}

.tips-box strong {
    color: #e65100;
}

.keyframes-list {
    background: #f8fafc;
    border-radius: 12px;
    padding: 20px;
    border: 1px solid #e2e8f0;
}

.keyframes-list h4 {
    margin-bottom: 15px;
    color: #1a1a2e;
}

.keyframes-list ul {
    list-style: none;
}

.keyframes-list li {
    padding: 10px 0;
    border-bottom: 1px solid #e2e8f0;
    display: flex;
    align-items: center;
    gap: 15px;
}

.keyframes-list li:last-child {
    border-bottom: none;
}

.frame-num {
    background: linear-gradient(90deg, #00d4ff, #7c3aed);
    color: #fff;
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 0.85rem;
    font-weight: 600;
    font-family: 'Courier New', monospace;
}

@media (max-width: 768px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .steps {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .demo-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .demo-layout {
        grid-template-columns: 1fr;
    }
    
    .nav-links {
        gap: 15px;
    }
    
    .nav-download {
        padding: 6px 15px;
        font-size: 0.9rem;
    }
    
    .hero-content h2 {
        font-size: 2rem;
    }
    
    .viewer-header {
        flex-direction: column;
        gap: 15px;
    }
    
    .screenshots-grid {
        grid-template-columns: 1fr;
    }
    
    .screenshot-wrapper {
        aspect-ratio: 16 / 10;
    }
    
    .download-info {
        grid-template-columns: 1fr;
    }
    
    .download-features {
        flex-direction: column;
        gap: 20px;
        align-items: center;
    }
    
    .btn-download {
        padding: 15px 30px;
        font-size: 1rem;
    }
    
    .frame-viewer {
        height: 300px;
    }
    
    .screenshot-display {
        grid-template-columns: 1fr;
    }
    
    .screenshot-annotations {
        order: 2;
    }
    
    .guide-steps {
        grid-template-columns: 1fr;
    }
    
    .guide-controls {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .speed-selector {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .info-display {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .result-demo {
        flex-direction: column;
        text-align: center;
    }
    
    .progress-info {
        grid-template-columns: 1fr;
    }
    
    .toolbar-demo {
        flex-wrap: wrap;
        gap: 20px;
    }
    
    .face-rec-item {
        flex-direction: column;
        text-align: center;
    }
    
    .annotation-item {
        font-size: 0.9rem;
    }
    
    .annotation-num {
        width: 24px;
        height: 24px;
        font-size: 0.85rem;
    }
    
    .usage-guide h2 {
        font-size: 1.8rem;
    }
    
    .guide-section h3 {
        font-size: 1.2rem;
    }
    
    .step-header h4 {
        font-size: 1rem;
    }
}