/* ========== 全局变量 ========== */
:root {
    --primary: #4F46E5;
    --primary-dark: #4338CA;
    --primary-light: #818CF8;
    --secondary: #10B981;
    --warning: #F59E0B;
    --danger: #EF4444;
    --text: #1F2937;
    --text-light: #6B7280;
    --text-lighter: #9CA3AF;
    --bg: #F9FAFB;
    --bg-white: #FFFFFF;
    --border: #E5E7EB;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 12px rgba(0, 0, 0, 0.15);
    --radius: 12px;
    --radius-sm: 8px;
}

/* ========== 基础样式 ========== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
}

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

/* ========== 按钮 ========== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 15px;
    font-weight: 500;
    text-decoration: none;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

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

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

.btn-lg {
    padding: 16px 32px;
    font-size: 16px;
}

.btn-price {
    background: rgba(255, 255, 255, 0.2);
    padding: 4px 12px;
    border-radius: 6px;
    font-weight: 600;
}

/* ========== 导航栏 ========== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: box-shadow 0.3s;
}

.navbar.scrolled {
    box-shadow: var(--shadow);
}

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

.nav-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 24px;
    font-weight: 700;
    color: var(--text);
    text-decoration: none;
}

.logo-icon {
    font-size: 28px;
}

.logo-text {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    gap: 32px;
}

.nav-link {
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text);
    transition: all 0.3s;
}

/* ========== Hero区域 ========== */
.hero {
    position: relative;
    padding: 160px 0 100px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: -1;
}

.hero-gradient {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, 
        rgba(79, 70, 229, 0.05) 0%, 
        rgba(129, 140, 248, 0.05) 50%,
        rgba(255, 255, 255, 0) 100%);
}

.hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: white;
    padding: 8px 16px;
    border-radius: 100px;
    font-size: 14px;
    color: var(--text-light);
    box-shadow: var(--shadow);
    margin-bottom: 24px;
}

.hero-title {
    font-size: 56px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 24px;
    letter-spacing: -0.02em;
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 18px;
    color: var(--text-light);
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

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

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

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

.stat-value {
    display: block;
    font-size: 32px;
    font-weight: 700;
    color: var(--primary);
}

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

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

/* ========== Section ========== */
.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-tag {
    display: inline-block;
    background: rgba(79, 70, 229, 0.1);
    color: var(--primary);
    padding: 6px 16px;
    border-radius: 100px;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 16px;
}

.section-title {
    font-size: 40px;
    font-weight: 700;
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.section-desc {
    font-size: 18px;
    color: var(--text-light);
}

/* ========== 功能介绍 ========== */
.features {
    padding: 100px 0;
    background: white;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
}

.feature-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px;
    transition: all 0.3s;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.feature-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: 16px;
    margin-bottom: 24px;
}

.feature-icon svg {
    stroke: white;
}

.feature-title {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 12px;
}

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

/* ========== 优势 ========== */
.advantages {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 32px;
}

.advantage-item {
    display: flex;
    gap: 16px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 24px;
    border-radius: var(--radius);
}

.advantage-icon {
    flex-shrink: 0;
    width: 32px;
    height: 32px;
    background: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    font-weight: 700;
}

.advantage-content h4 {
    color: white;
    font-size: 18px;
    margin-bottom: 8px;
}

.advantage-content p {
    color: rgba(255, 255, 255, 0.8);
    font-size: 14px;
}

/* ========== FAQ ========== */
.faq {
    padding: 100px 0;
}

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

.faq-item {
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 16px;
    overflow: hidden;
    background: white;
}

.faq-question {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px;
    background: none;
    border: none;
    font-size: 16px;
    font-weight: 500;
    text-align: left;
    cursor: pointer;
    transition: background 0.2s;
}

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

.faq-icon {
    transition: transform 0.3s;
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
}

.faq-answer {
    padding: 0 24px;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s;
}

.faq-item.active .faq-answer {
    padding: 0 24px 24px;
    max-height: 500px;
}

.faq-answer p {
    color: var(--text-light);
    line-height: 1.8;
}

/* ========== CTA ========== */
.cta {
    padding: 100px 0;
    background: white;
}

.cta-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.cta-title {
    font-size: 40px;
    font-weight: 700;
    margin-bottom: 16px;
}

.cta-desc {
    font-size: 18px;
    color: var(--text-light);
    margin-bottom: 32px;
}

.cta-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
}

/* ========== Footer ========== */
.footer {
    padding: 48px 0;
    background: var(--bg);
    border-top: 1px solid var(--border);
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 24px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 20px;
    font-weight: 700;
    color: var(--text);
}

.footer-name {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.footer-links {
    display: flex;
    gap: 32px;
}

.footer-links a {
    color: var(--text-light);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.2s;
}

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

.footer-copyright {
    color: var(--text-lighter);
    font-size: 13px;
}

/* ========== 响应式 ========== */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        border-bottom: 1px solid var(--border);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s;
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-toggle {
        display: flex;
    }

    .hero {
        padding: 120px 0 60px;
    }

    .hero-title {
        font-size: 36px;
    }

    .hero-desc {
        font-size: 16px;
    }

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

    .hero-stats {
        flex-direction: column;
        gap: 24px;
    }

    .stat-divider {
        width: 80px;
        height: 1px;
    }

    .section-title {
        font-size: 28px;
    }

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

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

    .cta-title {
        font-size: 28px;
    }

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

    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: 16px;
    }
}