/* GLACIER ATLAS - Design System */
@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;600&family=Manrope:wght@400;600;800&display=swap');

:root {
    --bg-main: #EEF4F8; /* frost white */
    --surface: #FFFFFF;
    --primary-navy: #0F2A43; /* deep navy */
    --primary-accent: #0F5E9C; /* glacier blue */
    --ice-highlight: #8FCDE0;
    --text-muted: #5B7285;
    --border-color: #D7E3EC;
    --radius: 10px;
}

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

body {
    background-color: var(--bg-main);
    color: var(--primary-navy);
    font-family: 'Manrope', -apple-system, BlinkMacSystemFont, sans-serif;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--primary-navy);
    font-weight: 800;
    line-height: 1.2;
}

p {
    color: var(--text-muted);
    font-weight: 400;
}

a {
    text-decoration: none;
    color: var(--primary-accent);
    transition: color 0.2s ease;
}

a:hover {
    color: var(--primary-navy);
}

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

/* 导航栏 */
.navbar {
    background: var(--bg-main);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}
.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 72px; /* 8px grid */
}
.logo-container {
    display: flex;
    align-items: center;
    gap: 12px;
}
.logo-text {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary-navy);
    letter-spacing: -0.5px;
}
nav {
    display: flex;
    gap: 32px;
}
nav a {
    color: var(--text-muted);
    font-weight: 600;
    font-size: 0.95rem;
}
nav a:hover {
    color: var(--primary-accent);
}

/* 按钮通用样式 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border-radius: var(--radius);
    font-weight: 600;
    transition: all 0.2s ease;
    cursor: pointer;
    border: none;
    font-family: 'Manrope', sans-serif;
}
.btn-primary {
    background-color: var(--primary-navy);
    color: #fff;
}
.btn-primary:hover {
    background-color: #081624;
    color: #fff;
    transform: translateY(-1px);
    box-shadow: 0 8px 16px rgba(15, 42, 67, 0.15);
}
.btn-secondary {
    background-color: transparent;
    color: var(--primary-navy);
    border: 1px solid var(--border-color);
}
.btn-secondary:hover {
    background-color: var(--surface);
    border-color: var(--ice-highlight);
    transform: translateY(-1px);
    box-shadow: 0 8px 16px rgba(15, 42, 67, 0.05);
}
.btn-large {
    padding: 16px 32px;
    font-size: 1.1rem;
}
.btn-block {
    display: flex;
    width: 100%;
}

/* 区域通用样式 */
.section {
    padding: 96px 0;
}
.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 64px;
}
.bg-light {
    background-color: var(--bg-main);
}
.bg-surface {
    background-color: var(--surface);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

/* 主视觉区 */
.hero {
    padding: 120px 0 96px;
    text-align: center;
}
.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 24px;
    letter-spacing: -1px;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}
.hero p {
    font-size: 1.25rem;
    max-width: 700px;
    margin: 0 auto 48px;
    line-height: 1.8;
}
.hero-actions {
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

/* 网格布局 */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}
.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
}

/* 卡片样式 */
.card {
    background: var(--surface);
    padding: 40px;
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 16px 32px rgba(15, 42, 67, 0.08);
}
.card-icon-wrapper {
    width: 64px;
    height: 64px;
    background: var(--bg-main);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
    border: 1px solid var(--border-color);
}
.card-icon {
    font-size: 1.8rem;
}
.card h3 {
    font-size: 1.25rem;
    margin-bottom: 16px;
}
.flex-center {
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}
.text-large {
    font-size: 3rem;
}

/* 价格卡片 */
.pricing-card {
    position: relative;
    padding: 48px 40px;
}
.pricing-card.featured {
    border: 2px solid var(--ice-highlight);
    background-color: var(--surface);
    box-shadow: 0 16px 48px rgba(143, 205, 224, 0.15);
}
.badge {
    position: absolute;
    top: -14px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--ice-highlight);
    color: var(--primary-navy);
    padding: 4px 16px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 800;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}
.price-box {
    margin: 24px 0 32px;
}
.price {
    font-family: 'IBM Plex Mono', monospace;
    font-size: 3.5rem;
    font-weight: 600;
    color: var(--primary-navy);
    line-height: 1;
}
.price span {
    font-size: 1.2rem;
    color: var(--text-muted);
    font-family: 'Manrope', sans-serif;
    font-weight: 600;
}
.features-list {
    list-style: none;
    margin-bottom: 40px;
}
.features-list li {
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 12px;
}
.features-list li::before {
    content: "✓";
    color: var(--primary-accent);
    font-weight: 800;
}

/* FAQ */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}
.faq-item {
    background: var(--surface);
    padding: 24px 32px;
    border-radius: var(--radius);
    margin-bottom: 16px;
    border: 1px solid var(--border-color);
}
.faq-item h4 {
    font-size: 1.15rem;
    margin-bottom: 12px;
}

/* 用户评价 */
.testimonial {
    font-style: normal;
    padding: 40px;
}
.testimonial p {
    font-size: 1.1rem;
    color: var(--primary-navy);
    line-height: 1.8;
}
.author {
    margin-top: 24px;
    font-weight: 600;
    color: var(--text-muted);
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 12px;
}
.author::before {
    content: "";
    display: block;
    width: 24px;
    height: 1px;
    background: var(--border-color);
}

/* 页脚 */
.footer {
    background: var(--primary-navy);
    color: var(--surface);
    padding: 80px 0 32px;
    text-align: center;
}
.footer-links {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-bottom: 48px;
}
.footer-links a {
    color: var(--ice-highlight);
    font-weight: 600;
}
.footer-links a:hover {
    color: var(--surface);
}
.copyright {
    color: #3b5266;
    font-size: 0.9rem;
    border-top: 1px solid #1a3c5a;
    padding-top: 32px;
}

/* 响应式 */
@media (max-width: 768px) {
    nav {
        display: none;
    }
    .hero {
        padding: 80px 0 64px;
    }
    .hero h1 {
        font-size: 2.5rem;
    }
    .grid-3, .grid-2 {
        grid-template-columns: 1fr;
    }
    .hero-actions {
        flex-direction: column;
        align-items: stretch;
    }
    .btn {
        width: 100%;
    }
    .footer-links {
        flex-direction: column;
        gap: 24px;
    }
    .pricing-card {
        padding: 32px 24px;
    }
}

/* 悬浮按钮 */
.floating-btn {
    position: fixed;
    bottom: 40px;
    right: 40px;
    width: 52px;
    height: 52px;
    background-color: var(--primary-navy);
    color: var(--surface);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    box-shadow: 0 8px 16px rgba(15, 42, 67, 0.2);
    opacity: 0.8;
    transition: all 0.3s ease;
    z-index: 1000;
    text-decoration: none;
}
.floating-btn:hover {
    opacity: 1;
    transform: translateY(-3px);
    color: var(--ice-highlight);
}
/* 下一篇文章卡片 */
.next-article {
    margin-top: 48px;
    padding-top: 32px;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.next-article-label {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 8px;
    display: block;
}
.next-article-title {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--primary-navy);
}
/* Hero Image */
.hero-image-wrapper {
    margin: 48px auto 0;
    max-width: 1000px;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: 0 24px 48px rgba(15, 42, 67, 0.1);
    border: 1px solid var(--border-color);
    line-height: 0;
}
.hero-image-wrapper img {
    width: 100%;
    height: auto;
    display: block;
}