@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@400;500&family=Space+Grotesk:wght@500;700&display=swap');

:root {
    /* 瓷白底色 */
    --bg-color: #F4F6F5; 
    /* 冰川青 */
    --primary: #115E67; 
    --primary-hover: #0d4a51;
    /* 墨蓝 */
    --dark-block: #16323A; 
    /* 日晖金 */
    --accent: #E9A13B; 
    /* 薄雾 (面板与边框) */
    --panel-border: #DDE7E4; 
    
    --text-main: #2b353f;
    --text-muted: #6b7a85;
    
    /* 严格 8px 网格 */
    --grid-unit: 8px;
    --radius: 2px; /* 取消圆润感，回归工程感 */
}

/* 基础重置与字体 */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'IBM Plex Sans', "PingFang SC", "Microsoft YaHei", sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, .logo, .price {
    font-family: 'Space Grotesk', "PingFang SC", sans-serif;
    font-weight: 500;
}

h1 { font-weight: 700; }
h3 { font-weight: 700; }

h2 {
    font-size: 32px;
    margin-bottom: calc(var(--grid-unit) * 6);
    text-align: center;
    color: var(--dark-block);
}

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

/* 克制的微动效（淡入并上移 8px） */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.card, .price-card, .faq-item, .hero-content {
    animation: fadeInUp 0.8s ease-out forwards;
}

/* 网格与布局 */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 calc(var(--grid-unit) * 3);
}

section {
    padding: calc(var(--grid-unit) * 12) 0;
    /* 发丝分隔线 */
    border-bottom: 1px solid var(--panel-border); 
}
section:last-of-type {
    border-bottom: none;
}

/* 导航栏 */
header {
    background: rgba(244, 246, 245, 0.9);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--panel-border);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: calc(var(--grid-unit) * 2.5) 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 calc(var(--grid-unit) * 3);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 22px;
    color: var(--dark-block);
    letter-spacing: -0.5px;
    font-weight: 700;
}

nav ul {
    list-style: none;
    display: flex;
    gap: calc(var(--grid-unit) * 4);
}

nav a {
    color: var(--text-muted);
    font-size: 14px;
    font-weight: 500;
}
nav a:hover {
    color: var(--primary);
}

/* 按钮 - 严谨的矩形 */
.btn {
    display: inline-block;
    padding: calc(var(--grid-unit) * 1.5) calc(var(--grid-unit) * 4);
    font-weight: 500;
    font-size: 15px;
    text-align: center;
    border: 1px solid transparent;
    cursor: pointer;
    transition: all 0.2s ease;
    border-radius: var(--radius);
}

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

.btn-secondary {
    background-color: transparent;
    border-color: var(--panel-border);
    color: var(--dark-block);
}
.btn-secondary:hover {
    border-color: var(--primary);
    color: var(--primary);
}

/* 主视觉 Hero区 */
.hero {
    background-color: var(--dark-block);
    color: var(--bg-color);
    padding: calc(var(--grid-unit) * 15) calc(var(--grid-unit) * 3);
    text-align: center;
    margin: 0;
    max-width: 100%;
    border-bottom: none;
}

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

.hero h1 {
    font-size: 48px;
    margin-bottom: calc(var(--grid-unit) * 3);
    color: #fff;
}

.hero .subtitle {
    font-size: 16px;
    color: var(--panel-border);
    margin-bottom: calc(var(--grid-unit) * 5);
    font-family: 'IBM Plex Sans', sans-serif;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: calc(var(--grid-unit) * 2);
}
.hero-actions .btn-secondary {
    border-color: rgba(255, 255, 255, 0.3);
    color: #fff;
}
.hero-actions .btn-secondary:hover {
    border-color: #fff;
}

/* 卡片系统 */
.card-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: calc(var(--grid-unit) * 4);
}
.two-cols {
    grid-template-columns: repeat(2, 1fr);
}

.card {
    background: #fff;
    border: 1px solid var(--panel-border);
    padding: calc(var(--grid-unit) * 5);
    transition: transform 0.2s ease, border-color 0.2s ease;
    border-radius: var(--radius);
    text-align: left; /* 工程感：左对齐，去除中间对齐的活泼感 */
}

.card:hover {
    transform: translateY(-2px);
    border-color: var(--primary);
}

.card .icon {
    font-size: 24px;
    margin-bottom: calc(var(--grid-unit) * 3);
    color: var(--primary);
    opacity: 0.8;
}

.card h3 {
    font-size: 18px;
    margin-bottom: calc(var(--grid-unit) * 2);
    color: var(--dark-block);
}

.card p {
    font-size: 14px;
    color: var(--text-muted);
}

/* 价格表 */
.price-card {
    display: flex;
    flex-direction: column;
}
.price {
    font-size: 40px;
    color: var(--dark-block);
    margin: calc(var(--grid-unit) * 2) 0 calc(var(--grid-unit) * 4) 0;
    /* 等宽数字 */
    font-variant-numeric: tabular-nums; 
}
.price span {
    font-size: 14px;
    color: var(--text-muted);
    font-family: 'IBM Plex Sans', sans-serif;
    font-weight: 400;
}

.price-card ul {
    list-style: none;
    margin-bottom: calc(var(--grid-unit) * 5);
    flex-grow: 1;
}
.price-card li {
    font-size: 14px;
    color: var(--text-muted);
    margin-bottom: calc(var(--grid-unit) * 1.5);
    display: flex;
    align-items: center;
}
.price-card li::before {
    content: '';
    display: inline-block;
    width: 4px;
    height: 4px;
    background: var(--primary);
    margin-right: 12px;
}

.price-card.featured {
    border: 1px solid var(--accent);
    position: relative;
}
.price-card.featured::before {
    content: 'RECOMMENDED';
    position: absolute;
    top: -10px;
    left: calc(var(--grid-unit) * 5);
    background: var(--accent);
    color: #fff;
    font-size: 10px;
    font-weight: 700;
    padding: 2px 8px;
    letter-spacing: 1px;
}
.price-card.featured .btn-primary {
    background-color: var(--accent);
    color: #fff;
}
.price-card.featured .btn-primary:hover {
    background-color: #d18a2d;
}

/* FAQ & Reviews */
.faq-list {
    display: flex;
    flex-direction: column;
    max-width: 800px;
    margin: 0 auto;
}
.faq-item {
    border: none;
    border-bottom: 1px solid var(--panel-border);
    padding: calc(var(--grid-unit) * 3) 0;
    background: transparent;
    border-radius: 0;
}
.faq-item:hover {
    transform: none;
    border-color: var(--primary);
}

.review-card {
    background: var(--bg-color);
}
.review-card p {
    font-style: italic;
    color: var(--text-main);
    margin-bottom: calc(var(--grid-unit) * 2);
}

/* 页脚 */
footer {
    background-color: var(--dark-block);
    color: var(--panel-border);
    padding: calc(var(--grid-unit) * 8) 0;
    text-align: center;
}
.footer-links {
    display: flex;
    justify-content: center;
    gap: calc(var(--grid-unit) * 4);
    margin-bottom: calc(var(--grid-unit) * 4);
}
.footer-links a {
    color: var(--panel-border);
    font-size: 14px;
}
.footer-links a:hover {
    color: #fff;
}
footer p {
    font-size: 12px;
    color: var(--text-muted);
}

/* 移动端适配 */
@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: calc(var(--grid-unit) * 2);
    }
    .hero h1 {
        font-size: 32px;
    }
    .hero-actions {
        flex-direction: column;
    }
    .card-grid, .two-cols {
        grid-template-columns: 1fr;
    }
}