/* ============================================
   EduSync AI - 高端 AI 教育公司官网
   设计风格：深色基调、优雅衬线、精致细节
   ============================================ */

:root {
    --bg-dark: #0a0c10;
    --bg-card: #12151c;
    --bg-elevated: #181c24;
    --text-primary: #f0f2f5;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    --accent: #c9a227;
    --accent-dim: #b8921f;
    --accent-glow: rgba(201, 162, 39, 0.15);
    --border: rgba(255, 255, 255, 0.06);
    --gradient-1: linear-gradient(135deg, #1a1d26 0%, #0a0c10 100%);
    --gradient-accent: linear-gradient(135deg, #c9a227 0%, #e8c547 50%, #b8921f 100%);
    --font-display: 'Cormorant Garamond', Georgia, serif;
    --font-body: 'Outfit', -apple-system, sans-serif;
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.7;
    overflow-x: hidden;
}

/* ========== 导航栏 ========== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1.25rem 2rem;
    background: rgba(10, 12, 16, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    transition: var(--transition);
}

.navbar.scrolled {
    padding: 0.75rem 2rem;
    background: rgba(10, 12, 16, 0.95);
}

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

.logo {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: 0.02em;
}

.logo-accent {
    color: var(--accent);
    font-weight: 400;
}

.nav-links {
    display: flex;
    gap: 2.5rem;
    list-style: none;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 400;
    transition: color var(--transition);
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
}

/* ========== Hero 区域 ========== */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    position: relative;
    padding: 8rem 2rem 4rem;
    text-align: center;
}

.hero-bg {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.4;
}

.orb-1 {
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
    top: -200px;
    left: 50%;
    transform: translateX(-50%);
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(26, 29, 38, 0.8) 0%, transparent 70%);
    bottom: -100px;
    right: -100px;
}

.grid-overlay {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse 80% 60% at 50% 50%, black, transparent);
}

.hero-content {
    position: relative;
    max-width: 820px;
}

.hero-tagline {
    font-size: 0.9rem;
    color: var(--accent);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    margin-bottom: 1.5rem;
    font-weight: 500;
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 300;
    line-height: 1.2;
    letter-spacing: 0.02em;
    margin-bottom: 1.5rem;
}

.hero-title .line {
    display: block;
}

.hero-title .accent {
    color: var(--accent);
    font-style: italic;
    font-weight: 400;
}

.hero-desc {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 560px;
    margin: 0 auto 2.5rem;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 1rem 2rem;
    font-size: 0.95rem;
    font-weight: 500;
    text-decoration: none;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--gradient-accent);
    color: #0a0c10;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px var(--accent-glow);
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border);
}

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

.hero-stats {
    position: relative;
    display: flex;
    align-items: center;
    gap: 2rem;
    margin-top: 5rem;
    padding: 2rem 3rem;
    background: rgba(24, 28, 36, 0.6);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: var(--border);
}

.stat {
    text-align: center;
}

.stat-value {
    display: block;
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 600;
    color: var(--accent);
}

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

.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-muted);
    font-size: 0.8rem;
}

.scroll-line {
    width: 1px;
    height: 40px;
    background: linear-gradient(to bottom, var(--accent), transparent);
    animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 1; }
}

/* ========== 通用区块 ========== */
.section {
    padding: 6rem 2rem;
    position: relative;
}

.section-inner {
    max-width: 1100px;
    margin: 0 auto;
}

.section-label {
    display: block;
    font-size: 0.8rem;
    color: var(--accent);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    margin-bottom: 0.75rem;
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 4vw, 2.75rem);
    font-weight: 300;
    line-height: 1.3;
}

/* ========== 关于我们 ========== */
.about {
    background: var(--gradient-1);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    margin-top: 3rem;
}

.about-lead {
    font-size: 1.15rem;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
}

.about-content p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.about-location {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    padding: 1.25rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
}

.about-location svg {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
    color: var(--accent);
}

.about-location div {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.about-location strong {
    color: var(--text-primary);
    font-size: 0.9rem;
}

.about-location span {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.about-visual {
    display: flex;
    justify-content: center;
}

.visual-card {
    width: 280px;
    padding: 3rem 2rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: var(--transition);
}

.visual-card:hover {
    border-color: rgba(201, 162, 39, 0.3);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.visual-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 1.5rem;
}

.visual-icon svg {
    width: 100%;
    height: 100%;
    color: var(--accent);
}

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

/* ========== 解决方案 ========== */
.services {
    background: var(--bg-dark);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    margin-top: 3rem;
}

.service-card {
    padding: 2.5rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.service-card:hover {
    border-color: rgba(201, 162, 39, 0.25);
    transform: translateY(-4px);
}

.service-icon {
    width: 48px;
    height: 48px;
    margin-bottom: 1.5rem;
}

.service-icon svg {
    width: 100%;
    height: 100%;
    color: var(--accent);
}

.service-card h3 {
    font-family: var(--font-display);
    font-size: 1.4rem;
    font-weight: 500;
    margin-bottom: 0.75rem;
}

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

/* ========== 核心技术 ========== */
.technology {
    background: var(--gradient-1);
}

.tech-list {
    margin-top: 3rem;
}

.tech-item {
    display: flex;
    gap: 2rem;
    padding: 2rem 0;
    border-bottom: 1px solid var(--border);
    transition: var(--transition);
}

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

.tech-item:hover {
    padding-left: 1rem;
}

.tech-num {
    font-family: var(--font-display);
    font-size: 1.5rem;
    color: var(--accent);
    opacity: 0.7;
    min-width: 3rem;
}

.tech-item h4 {
    font-size: 1.1rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

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

/* ========== 教育影响 ========== */
.impact {
    background: var(--bg-dark);
}

.impact-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 3rem;
}

.impact-card {
    padding: 3rem 2rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    text-align: center;
    transition: var(--transition);
}

.impact-card:hover {
    border-color: rgba(201, 162, 39, 0.3);
}

.impact-value {
    display: block;
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 600;
    color: var(--accent);
    margin-bottom: 0.5rem;
}

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

/* ========== 联系 ========== */
.contact {
    background: var(--gradient-1);
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    margin-top: 3rem;
    align-items: start;
}

.contact-content p {
    color: var(--text-secondary);
    margin: 1rem 0 2rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-item {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.contact-item strong {
    font-size: 0.9rem;
    color: var(--text-primary);
}

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

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-form input,
.contact-form textarea {
    padding: 1rem 1.25rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 0.95rem;
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
    color: var(--text-muted);
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--accent);
}

/* ========== 页脚 ========== */
.footer {
    padding: 3rem 2rem;
    border-top: 1px solid var(--border);
}

.footer-inner {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    gap: 2rem;
}

.footer-brand .logo {
    font-size: 1.5rem;
}

.footer-brand p {
    margin-top: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.footer-links {
    display: flex;
    gap: 2rem;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
}

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

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

/* ========== 响应式 ========== */
@media (max-width: 900px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        right: 2rem;
        flex-direction: column;
        gap: 1.5rem;
        padding: 2rem;
        background: var(--bg-elevated);
        border: 1px solid var(--border);
        border-radius: var(--radius-md);
        min-width: 200px;
        margin-top: 1rem;
    }

    .nav-links.open {
        display: flex;
    }

    .nav-toggle {
        display: flex;
    }

    .about-grid,
    .contact-wrapper {
        grid-template-columns: 1fr;
    }

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

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

    .hero-stats {
        flex-direction: column;
        gap: 1rem;
    }

    .stat-divider {
        width: 40px;
        height: 1px;
    }
}

@media (max-width: 600px) {
    .hero {
        padding: 6rem 1.5rem 3rem;
    }

    .hero-cta {
        flex-direction: column;
    }

    .section {
        padding: 4rem 1.5rem;
    }

    .footer-inner {
        flex-direction: column;
        text-align: center;
    }
}