:root {
    --primary: #0d9488;
    --primary-dark: #0f766e;
    --secondary: #0891b2;
    --accent: #06b6d4;
    --text-main: #1e293b;
    --text-light: #64748b;
    --bg-main: #f8fafc;
    --bg-card: #ffffff;
    --bg-gradient: linear-gradient(135deg, #f0fdfa 0%, #ecfeff 50%, #f0f9ff 100%);
    --border: #e2e8f0;
    --radius: 16px;
    --shadow-sm: 0 2px 8px rgba(13, 148, 136, 0.05);
    --shadow-md: 0 8px 24px rgba(13, 148, 136, 0.08);
    --shadow-lg: 0 16px 40px rgba(13, 148, 136, 0.12);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    color: var(--text-main);
    background: var(--bg-gradient);
    line-height: 1.6;
    overflow-x: hidden;
}

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

/* Header */
.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(13, 148, 136, 0.1);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-brand {
    font-size: 22px;
    font-weight: 800;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-brand i {
    -webkit-text-fill-color: var(--primary);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 28px;
    list-style: none;
}

.nav-menu a {
    color: var(--text-main);
    text-decoration: none;
    font-size: 15px;
    font-weight: 500;
    transition: color 0.3s;
}

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

.nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    color: var(--primary);
    cursor: pointer;
}

/* Hero */
.hero {
    padding: 100px 0 80px;
    position: relative;
    overflow: hidden;
    text-align: center;
}

.hero::before {
    content: '';
    position: absolute;
    top: -100px;
    left: 50%;
    transform: translateX(-50%);
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(13, 148, 136, 0.15) 0%, rgba(8, 145, 178, 0.05) 40%, transparent 70%);
    border-radius: 50%;
    z-index: 0;
    animation: pulse 8s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: translateX(-50%) scale(1); opacity: 0.8; }
    50% { transform: translateX(-50%) scale(1.1); opacity: 1; }
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 820px;
    margin: 0 auto;
}

.hero-badge {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(13, 148, 136, 0.1);
    color: var(--primary-dark);
    border-radius: 50px;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 24px;
    border: 1px solid rgba(13, 148, 136, 0.2);
}

.hero h1 {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 24px;
    color: var(--text-main);
}

.hero h1 span {
    background: linear-gradient(90deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 18px;
    color: var(--text-light);
    margin-bottom: 36px;
}

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

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: 50px;
    font-size: 16px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: #fff;
    box-shadow: 0 8px 20px rgba(13, 148, 136, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 28px rgba(13, 148, 136, 0.4);
}

.btn-outline {
    background: transparent;
    color: var(--primary-dark);
    border: 2px solid var(--primary);
}

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

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

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

.section-tag {
    color: var(--primary);
    font-size: 14px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 12px;
    display: block;
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 16px;
}

.section-desc {
    font-size: 16px;
    color: var(--text-light);
    max-width: 640px;
    margin: 0 auto;
}

/* About */
.about-card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 48px;
    box-shadow: var(--shadow-md);
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 48px;
    align-items: center;
    border: 1px solid var(--border);
}

.about-logo {
    background: linear-gradient(135deg, #f0fdfa, #ecfeff);
    border-radius: 12px;
    padding: 32px;
    text-align: center;
    border: 1px solid rgba(13, 148, 136, 0.1);
}

.about-text h3 {
    font-size: 28px;
    margin-bottom: 16px;
    color: var(--text-main);
}

.about-text p {
    color: var(--text-light);
    margin-bottom: 24px;
    font-size: 16px;
}

.tag-group {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.tag {
    padding: 8px 16px;
    background: rgba(13, 148, 136, 0.08);
    color: var(--primary-dark);
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
}

/* Grid */
.grid {
    display: grid;
    gap: 24px;
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 32px;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
    border: 1px solid var(--border);
    height: 100%;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(13, 148, 136, 0.3);
}

.card-icon {
    width: 56px;
    height: 56px;
    border-radius: 12px;
    background: linear-gradient(135deg, rgba(13, 148, 136, 0.1), rgba(8, 145, 178, 0.1));
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    margin-bottom: 20px;
}

.card h3 {
    font-size: 20px;
    margin-bottom: 12px;
    color: var(--text-main);
}

.card p {
    color: var(--text-light);
    font-size: 15px;
}

/* AI Models */
.ai-models {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
    max-width: 900px;
    margin: 0 auto;
}

.ai-model {
    padding: 10px 20px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 50px;
    font-weight: 600;
    color: var(--text-main);
    font-size: 14px;
    transition: all 0.3s;
    cursor: default;
}

.ai-model:hover {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: #fff;
    border-color: transparent;
    transform: translateY(-2px);
}

/* Process */
.process {
    position: relative;
    padding: 20px 0;
}

.process-step {
    display: flex;
    align-items: flex-start;
    margin-bottom: 32px;
    position: relative;
}

.process-step:last-child {
    margin-bottom: 0;
}

.process-step::before {
    content: '';
    position: absolute;
    left: 24px;
    top: 56px;
    bottom: -40px;
    width: 2px;
    background: linear-gradient(to bottom, var(--primary), var(--accent));
}

.process-step:last-child::before {
    display: none;
}

.process-num {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 18px;
    flex-shrink: 0;
    margin-right: 20px;
    z-index: 1;
    box-shadow: 0 4px 12px rgba(13, 148, 136, 0.3);
}

.process-content {
    background: var(--bg-card);
    padding: 24px;
    border-radius: 12px;
    border: 1px solid var(--border);
    flex-grow: 1;
    box-shadow: var(--shadow-sm);
}

.process-content h4 {
    font-size: 18px;
    margin-bottom: 8px;
    color: var(--text-main);
}

.process-content p {
    color: var(--text-light);
    font-size: 14px;
}

/* Reviews */
.review-card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 28px;
    border: 1px solid var(--border);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s;
}

.review-card:hover {
    box-shadow: var(--shadow-md);
}

.review-header {
    display: flex;
    align-items: center;
    margin-bottom: 16px;
    gap: 12px;
}

.review-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 20px;
}

.review-info h4 {
    font-size: 16px;
    color: var(--text-main);
}

.review-info span {
    font-size: 13px;
    color: var(--text-light);
}

.stars {
    color: #fbbf24;
    font-size: 14px;
}

.review-text {
    color: var(--text-light);
    font-size: 14px;
    line-height: 1.6;
}

/* Table */
.compare-table {
    width: 100%;
    background: var(--bg-card);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    border-collapse: collapse;
}

.compare-table th, 
.compare-table td {
    padding: 20px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.compare-table th {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: #fff;
    font-weight: 600;
}

.compare-table tr:last-child td {
    border-bottom: none;
}

.compare-table tr:hover {
    background: rgba(13, 148, 136, 0.03);
}

.compare-table .highlight {
    color: var(--primary-dark);
    font-weight: 600;
}

/* Score Box */
.score-box {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: #fff;
    padding: 40px;
    border-radius: var(--radius);
    text-align: center;
    margin-bottom: 32px;
    box-shadow: var(--shadow-md);
}

.score-num {
    font-size: 56px;
    font-weight: 800;
    line-height: 1;
    margin-bottom: 8px;
}

.score-label {
    font-size: 18px;
    opacity: 0.9;
}

.score-stars {
    color: #fbbf24;
    font-size: 24px;
    margin-top: 12px;
}

/* Training */
.training-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 16px;
}

.training-list li {
    background: var(--bg-card);
    padding: 20px 24px;
    border-radius: 12px;
    border-left: 4px solid var(--primary);
    box-shadow: var(--shadow-sm);
    font-weight: 500;
    color: var(--text-main);
    transition: all 0.3s;
}

.training-list li:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow-md);
}

/* FAQ */
.faq-item {
    background: var(--bg-card);
    border-radius: 12px;
    margin-bottom: 16px;
    border: 1px solid var(--border);
    overflow: hidden;
    transition: all 0.3s;
}

.faq-item[open] {
    box-shadow: var(--shadow-sm);
    border-color: rgba(13, 148, 136, 0.3);
}

.faq-summary {
    padding: 20px 24px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-main);
    list-style: none;
    font-size: 16px;
}

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

.faq-summary i {
    transition: transform 0.3s;
    color: var(--primary);
}

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

.faq-content {
    padding: 0 24px 20px;
    color: var(--text-light);
    font-size: 15px;
}

/* Network */
.network-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    text-align: center;
}

.stat-box {
    background: var(--bg-card);
    padding: 32px 16px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-sm);
}

.stat-num {
    font-size: 36px;
    font-weight: 800;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
}

.stat-label {
    color: var(--text-light);
    font-size: 14px;
}

/* Contact Form */
.contact-form {
    background: var(--bg-card);
    padding: 40px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-main);
    font-size: 14px;
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 15px;
    font-family: inherit;
    background: #fff;
    transition: all 0.3s;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.1);
}

textarea.form-control {
    resize: vertical;
    min-height: 120px;
}

/* Articles */
.article-item {
    display: flex;
    align-items: center;
    padding: 20px;
    background: var(--bg-card);
    border-radius: 12px;
    margin-bottom: 12px;
    border: 1px solid var(--border);
    text-decoration: none;
    color: var(--text-main);
    transition: all 0.3s;
}

.article-item:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-sm);
    border-color: rgba(13, 148, 136, 0.3);
}

.article-item i {
    color: var(--primary);
    margin-right: 16px;
    font-size: 20px;
}

.article-item span {
    flex-grow: 1;
    font-weight: 500;
}

.article-item .date {
    color: var(--text-light);
    font-size: 14px;
    font-weight: 400;
}

/* Footer */
.footer {
    background: #0f172a;
    color: #cbd5e1;
    padding: 60px 0 30px;
    margin-top: 80px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 40px;
}

.footer-brand h3 {
    color: #fff;
    font-size: 24px;
    margin-bottom: 16px;
}

.footer-brand p {
    color: #94a3b8;
    font-size: 14px;
    margin-bottom: 20px;
    line-height: 1.6;
}

.footer-links h4 {
    color: #fff;
    font-size: 16px;
    margin-bottom: 16px;
}

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

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

.footer-links a {
    color: #94a3b8;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: var(--accent);
}

.footer-bottom {
    border-top: 1px solid #1e293b;
    padding-top: 20px;
    text-align: center;
    color: #64748b;
    font-size: 14px;
}

/* Hidden */
.hidden-data {
    display: none;
}

/* Responsive */
@media (max-width: 992px) {
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
    .about-card { grid-template-columns: 1fr; }
    .network-stats { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1fr; gap: 32px; }
}

@media (max-width: 768px) {
    .nav-menu { display: none; }
    .nav-toggle { display: block; }
    .nav-menu.active {
        display: flex;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        padding: 20px;
        box-shadow: var(--shadow-md);
        border-top: 1px solid var(--border);
    }
    .hero h1 { font-size: 32px; }
    .section-title { font-size: 28px; }
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    .score-num { font-size: 42px; }
}

/* Animations */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}