/**
 * ============================================
 * 千羽网络 官网样式表 v3.0
 * 设计方向：Editorial Minimal + Warm Luxury
 * ============================================
 */

/* ============================================
   1. CSS 变量
   ============================================ */
:root {
    /* 背景色 - 温暖的米白 */
    --bg-primary: #FAFAF8;
    --bg-secondary: #F5F4F0;
    --bg-card: #FFFFFF;
    --bg-dark: #1A1A1A;
    
    /* 主色 - 深炭黑 */
    --text-primary: #1A1A1A;
    --text-secondary: #6B6B6B;
    --text-muted: #9A9A9A;
    
    /* 强调色 - 暖铜色 */
    --accent: #C4956A;
    --accent-dark: #A67C52;
    --accent-light: #E8D5C4;
    
    /* 渐变 */
    --gradient-warm: linear-gradient(135deg, #C4956A 0%, #E8D5C4 100%);
    --gradient-dark: linear-gradient(180deg, #1A1A1A 0%, #2D2D2D 100%);
    
    /* 边框 */
    --border-light: rgba(0, 0, 0, 0.06);
    --border-accent: rgba(196, 149, 106, 0.3);
    
    /* 阴影 - 精致的柔和阴影 */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 8px 30px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.08);
    
    /* 圆角 */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --radius-xl: 32px;
    
    /* 过渡 */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* 字体 */
    --font-display: "Source Han Serif SC", "Noto Serif SC", Georgia, "Songti SC", serif;
    --font-body: "Inter", "Noto Sans SC", -apple-system, sans-serif;
}

/* ============================================
   2. 基础重置
   ============================================ */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-body);
    background: var(--bg-primary);
    color: var(--text-secondary);
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

a {
    color: inherit;
    text-decoration: none;
}

/* ============================================
   3. 排版
   ============================================ */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 500;
    color: var(--text-primary);
    line-height: 1.2;
}

.display-xl {
    font-size: clamp(3rem, 8vw, 6rem);
    font-weight: 400;
    letter-spacing: -0.03em;
    line-height: 1.05;
}

.display-lg {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 400;
    letter-spacing: -0.02em;
}

.display-md {
    font-size: clamp(1.75rem, 3vw, 2.5rem);
    font-weight: 400;
}

.text-lg {
    font-size: 1.25rem;
    line-height: 1.7;
}

.text-sm {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.text-accent {
    color: var(--accent);
}

/* ============================================
   4. 布局
   ============================================ */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 32px;
}

.container-sm {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 32px;
}

.section {
    padding: 120px 0;
}

.section-lg {
    padding: 160px 0;
}

/* ============================================
   5. 导航栏
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: 24px 0;
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: rgba(250, 250, 248, 0.9);
    backdrop-filter: blur(20px);
    padding: 16px 0;
    border-bottom: 1px solid var(--border-light);
}

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

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.navbar-brand img {
    height: 32px;
}

.navbar-brand span {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--text-primary);
}

.navbar-menu {
    display: flex;
    align-items: center;
    gap: 48px;
    list-style: none;
}

.navbar-menu a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    position: relative;
    padding: 4px 0;
    transition: color var(--transition-fast);
}

.navbar-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--accent);
    transition: width var(--transition-fast);
}

.navbar-menu a:hover,
.navbar-menu a.active {
    color: var(--text-primary);
}

.navbar-menu a:hover::after,
.navbar-menu a.active::after {
    width: 100%;
}

.navbar-cta {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 28px;
    background: var(--text-primary);
    color: var(--bg-primary);
    font-size: 0.9rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.navbar-cta:hover {
    background: var(--accent);
    color: white;
    transform: translateY(-2px);
}

.navbar-toggle {
    display: none;
    background: none;
    border: none;
    padding: 8px;
    cursor: pointer;
}

.navbar-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    margin: 6px 0;
    transition: all var(--transition-fast);
}

/* ============================================
   6. Hero 区域
   ============================================ */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    padding: 120px 0 80px;
    overflow: hidden;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
}

.hero-eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 32px;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--accent);
}

.hero-eyebrow::before {
    content: '';
    width: 40px;
    height: 1px;
    background: var(--accent);
}

.hero-title {
    margin-bottom: 32px;
}

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

.hero-title .line:last-child {
    color: var(--text-muted);
    font-style: italic;
    font-weight: 400;
}

.hero-desc {
    max-width: 540px;
    margin-bottom: 48px;
    font-size: 1.125rem;
    color: var(--text-secondary);
}

.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 16px 32px;
    font-size: 0.9rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-base);
    border: none;
}

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

.btn-primary:hover {
    background: var(--accent);
    color: white;
    transform: translateY(-2px);
}

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

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

/* Hero 装饰 */
.hero-decoration {
    position: absolute;
    top: 50%;
    right: -10%;
    transform: translateY(-50%);
    width: 600px;
    height: 600px;
    opacity: 0.03;
    pointer-events: none;
}

.hero-decoration svg {
    width: 100%;
    height: 100%;
}

/* ============================================
   7. 品牌/价值区块
   ============================================ */
.brand-section {
    padding: 80px 0;
    border-top: 1px solid var(--border-light);
    border-bottom: 1px solid var(--border-light);
    background: var(--bg-secondary);
}

.brand-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 48px;
}

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

.brand-number {
    font-family: var(--font-display);
    font-size: 3.5rem;
    font-weight: 400;
    color: var(--text-primary);
    line-height: 1;
    margin-bottom: 8px;
}

.brand-number span {
    color: var(--accent);
}

.brand-label {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* ============================================
   8. 产品/解决方案
   ============================================ */
.solutions {
    background: var(--bg-primary);
}

.section-header {
    margin-bottom: 80px;
    max-width: 600px;
}

.section-header.centered {
    text-align: center;
    margin-left: auto;
    margin-right: auto;
}

.section-label {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 20px;
}

.section-title {
    margin-bottom: 20px;
}

.section-desc {
    font-size: 1.1rem;
    color: var(--text-secondary);
}

.solutions-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.solution-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 48px 40px;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.solution-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--gradient-warm);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-base);
}

.solution-card:hover {
    border-color: var(--border-accent);
    box-shadow: var(--shadow-md);
    transform: translateY(-8px);
}

.solution-card:hover::before {
    transform: scaleX(1);
}

.solution-icon {
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    margin-bottom: 28px;
    font-size: 1.5rem;
}

.solution-title {
    font-size: 1.5rem;
    margin-bottom: 16px;
}

.solution-desc {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.solution-price {
    font-family: var(--font-display);
    font-size: 1.75rem;
    color: var(--accent);
    margin-bottom: 4px;
}

.solution-price span {
    font-size: 0.9rem;
    font-family: var(--font-body);
    color: var(--text-muted);
}

.solution-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-top: 20px;
    transition: gap var(--transition-fast);
}

.solution-link:hover {
    gap: 12px;
    color: var(--accent);
}

/* ============================================
   9. 特性列表
   ============================================ */
.features {
    background: var(--bg-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 80px;
    align-items: center;
}

.features-content {
    max-width: 480px;
}

.features-list {
    list-style: none;
}

.feature-item {
    display: flex;
    gap: 24px;
    padding: 32px 0;
    border-bottom: 1px solid var(--border-light);
}

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

.feature-icon {
    width: 48px;
    height: 48px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    font-size: 1.25rem;
}

.feature-content h4 {
    font-size: 1.125rem;
    margin-bottom: 8px;
}

.feature-content p {
    font-size: 0.95rem;
    color: var(--text-muted);
}

.features-visual {
    position: relative;
    height: 500px;
    background: var(--bg-dark);
    border-radius: var(--radius-xl);
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.features-visual::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 30% 30%, rgba(196, 149, 106, 0.15) 0%, transparent 50%);
}

.features-visual i {
    font-size: 8rem;
    color: var(--accent);
    opacity: 0.3;
}

/* ============================================
   10. CTA 区域
   ============================================ */
.cta-section {
    background: var(--bg-dark);
    padding: 120px 0;
    text-align: center;
}

.cta-title {
    color: white;
    margin-bottom: 20px;
}

.cta-desc {
    color: rgba(255, 255, 255, 0.6);
    font-size: 1.125rem;
    margin-bottom: 40px;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.cta-section .btn-primary {
    background: var(--accent);
}

.cta-section .btn-primary:hover {
    background: var(--accent-dark);
}

/* ============================================
   11. Footer
   ============================================ */
.footer {
    background: var(--bg-secondary);
    padding: 80px 0 40px;
    border-top: 1px solid var(--border-light);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 64px;
    margin-bottom: 64px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
}

.footer-brand img {
    height: 28px;
}

.footer-brand span {
    font-family: var(--font-display);
    font-size: 1.125rem;
}

.footer-desc {
    font-size: 0.95rem;
    color: var(--text-muted);
    max-width: 280px;
    line-height: 1.8;
}

.footer-title {
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 24px;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 14px;
}

.footer-links a {
    font-size: 0.95rem;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

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

.footer-contact li {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 16px;
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.footer-contact i {
    color: var(--accent);
    margin-top: 4px;
}

.footer-bottom {
    border-top: 1px solid var(--border-light);
    padding-top: 32px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-bottom p {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.footer-bottom a {
    color: var(--text-muted);
}

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

/* ============================================
   12. 动画
   ============================================ */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.animate-fadeInUp {
    animation: fadeInUp 0.8s ease forwards;
}

.animate-fadeIn {
    animation: fadeIn 0.6s ease forwards;
}

.animate-delay-1 { animation-delay: 0.1s; opacity: 0; }
.animate-delay-2 { animation-delay: 0.2s; opacity: 0; }
.animate-delay-3 { animation-delay: 0.3s; opacity: 0; }
.animate-delay-4 { animation-delay: 0.4s; opacity: 0; }

/* ============================================
   13. 响应式
   ============================================ */
@media (max-width: 1024px) {
    .brand-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 40px;
    }
    
    .solutions-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .features-grid {
        gap: 48px;
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 40px;
    }
}

@media (max-width: 768px) {
    .section {
        padding: 80px 0;
    }
    
    .section-lg {
        padding: 100px 0;
    }
    
    .navbar-menu {
        display: none;
    }
    
    .navbar-toggle {
        display: block;
    }
    
    .hero {
        min-height: auto;
        padding: 160px 0 80px;
    }
    
    .brand-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 32px;
    }
    
    .brand-number {
        font-size: 2.5rem;
    }
    
    .solutions-grid,
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .features-visual {
        height: 300px;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
}