/* style.css - 小粽宝品牌官网样式 */

/* 1. 基础设置与变量 */
:root {
    --bg-color: #FAFAF9;
    --text-main: #111827; /* gray-900 */
    --text-secondary: #4B5563; /* gray-600 */
    --text-muted: #6B7280; /* gray-500 */
    --primary-color: #111827;
    --accent-color: #ea580c; /* 橙色强调 */
    --font-serif: 'Noto Serif SC', serif;
    --font-sans: 'Noto Sans SC', sans-serif;
    --max-width: 1280px;
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-color);
    color: var(--text-secondary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, .font-serif {
    font-family: var(--font-serif);
    color: var(--text-main);
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.3s ease;
}

img {
    max-width: 100%;
    display: block;
}

/* 通用容器 */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* 2. 导航栏 (Navbar) */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(0,0,0,0.03);
    padding: 20px 0;
    transition: all 0.3s ease;
}

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

.logo-group {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: bold;
    letter-spacing: 0.1em;
}

.logo-divider {
    height: 16px;
    width: 1px;
    background-color: #d1d5db;
}

.logo-sub {
    font-size: 0.75rem;
    color: var(--text-muted);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin-top: 4px;
}

.nav-links {
    display: none; /* 移动端默认隐藏 */
}

.nav-links a {
    color: var(--text-secondary);
    font-weight: 500;
    margin: 0 24px;
}

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

.nav-cta a {
    font-size: 0.875rem;
    font-weight: bold;
    color: var(--text-main);
    border-bottom: 2px solid var(--text-main);
    padding-bottom: 2px;
}

.nav-cta a:hover {
    color: var(--text-secondary);
    border-color: var(--text-secondary);
}

/* 3. 首屏 (Hero) */
.hero {
    /* 请在这里填入你的背景图URL */
    background: linear-gradient(to right, rgba(255,255,255,0.9) 0%, rgba(255,255,255,0.4) 100%), url('placeholder.jpg'); 
    background-size: cover;
    background-position: center;
    height: 95vh; /* 视口高度 */
    display: flex;
    align-items: center;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr;
    width: 100%;
}

.hero-content {
    padding-top: 5rem;
}

.sub-tag {
    color: var(--text-muted);
    letter-spacing: 0.3em;
    text-transform: uppercase;
    font-size: 0.875rem;
    display: block;
    margin-bottom: 1.5rem;
}

.hero-title {
    font-size: 3rem;
    font-weight: bold;
    line-height: 1.2;
    margin-bottom: 2rem;
    letter-spacing: 0.05em;
}

.gradient-text {
    background: linear-gradient(to right, #374151, #111827);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.hero-desc {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    max-width: 28rem;
    font-weight: 300;
}

.hero-actions {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.btn-primary {
    background-color: var(--text-main);
    color: white;
    padding: 1rem 2.5rem;
    border-radius: 9999px;
    font-weight: bold;
    display: inline-block;
    text-align: center;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    transition: background-color 0.3s;
}

.btn-primary:hover {
    background-color: #1f2937;
}

.btn-secondary {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.play-icon {
    width: 2.5rem;
    height: 2.5rem;
    border-radius: 50%;
    border: 1px solid #d1d5db;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: border-color 0.3s;
}

.btn-secondary:hover .play-icon {
    border-color: var(--text-main);
}

/* 4. 时代之问 (Philosophy) */
.section {
    padding: 6rem 0;
}

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

.section-title {
    font-size: 1.875rem;
    font-weight: bold;
    margin-bottom: 3rem;
}

.problem-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 3rem;
    margin-bottom: 4rem;
}

.problem-item h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.big-number {
    font-family: var(--font-serif);
    font-size: 2.25rem;
    color: #d1d5db;
    margin-bottom: 1rem;
}

.quote-box {
    background-color: #F9FAFB;
    padding: 2rem;
    border-radius: 1rem;
    display: inline-block;
}

.quote-text {
    font-size: 1.125rem;
    font-style: italic;
    font-family: var(--font-serif);
}

/* 5. 脑科学 (Science) */
.bg-gray-light {
    background-color: #F5F5F4;
    position: relative;
    overflow: hidden;
}

.bg-decor-text {
    position: absolute;
    top: 2.5rem;
    left: 0;
    font-size: 8rem;
    color: #E5E7EB;
    opacity: 0.4;
    font-family: var(--font-serif);
    pointer-events: none;
    z-index: 1;
}

.science-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 10;
}

.feature-tag {
    color: #15803d; /* green-700 */
    font-weight: bold;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    font-size: 0.875rem;
    display: block;
    margin-bottom: 1rem;
}

.science-list {
    margin-top: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.science-item {
    display: flex;
    gap: 1rem;
}

.icon-box {
    width: 3rem;
    height: 3rem;
    background: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    flex-shrink: 0;
}

.image-wrapper {
    position: relative;
}

.image-wrapper img {
    border-radius: 1rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    filter: grayscale(100%);
    transition: filter 0.7s;
}

.image-wrapper img:hover {
    filter: grayscale(0%);
}

.cert-box {
    position: absolute;
    bottom: -1.5rem;
    left: -1.5rem;
    background: white;
    padding: 1.5rem;
    border-radius: 0.75rem;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    max-width: 20rem;
}

/* 6. 产品 (Collections) */
.collection-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

.product-card {
    background: white;
    border-radius: 1rem;
    overflow: hidden;
    transition: transform 0.5s ease, box-shadow 0.5s ease;
    cursor: pointer;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px -10px rgba(0,0,0,0.05);
}

.product-img-box {
    position: relative;
    padding-bottom: 125%; /* 4:5 Aspect Ratio */
    background-color: #f3f4f6;
    overflow: hidden;
}

.product-img-box img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.7s;
}

.product-card:hover .product-img-box img {
    transform: scale(1.05);
}

.product-info {
    padding: 2rem;
    text-align: center;
}

.link-line {
    font-size: 0.75rem;
    font-weight: bold;
    border-bottom: 1px solid var(--text-main);
    padding-bottom: 4px;
}

/* 7. 练兵场 (Footer CTA) */
.cta-section {
    background-color: #111827;
    color: white;
    padding: 5rem 0;
    text-align: center;
}

.cta-section h2 {
    color: white;
}

.cta-section p {
    color: #9CA3AF; /* gray-400 */
    max-width: 40rem;
    margin: 0 auto 2.5rem auto;
}

/* 8. 页脚 (Footer) */
footer {
    background-color: #F9FAFB;
    padding-top: 4rem;
    padding-bottom: 2rem;
    border-top: 1px solid #e5e7eb;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-col h4 {
    margin-bottom: 1rem;
    font-size: 1rem;
}

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

.footer-col ul li {
    margin-bottom: 0.5rem;
}

.footer-col a, .footer-col li {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.footer-col a:hover {
    color: var(--text-main);
}

.footer-bottom {
    border-top: 1px solid #e5e7eb;
    padding-top: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    font-size: 0.75rem;
    color: #9CA3AF;
}

/* 媒体查询：响应式设计 */
@media (min-width: 768px) {
    /* 桌面端导航 */
    .nav-links {
        display: flex;
    }
    
    /* 桌面端 Hero */
    .hero-title {
        font-size: 3.5rem;
    }
    .hero-grid {
        grid-template-columns: 1fr 1fr;
    }
    .hero-actions {
        flex-direction: row;
    }

    /* 桌面端网格 */
    .problem-grid, .collection-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .science-grid, .footer-grid {
        grid-template-columns: 2fr 1fr 1fr; /* Footer 特殊比例 */
    }

    .science-grid {
        grid-template-columns: 1fr 1fr;
    }
    
    .footer-bottom {
        flex-direction: row;
        justify-content: space-between;
    }
}