/* ============================================
   公共样式 - Header, Footer, 基础重置
   ============================================ */

/* --- CSS Variables --- */
:root {
    --primary: #0366d6;
    --primary-dark: #0256b9;
    --primary-light: #4285f4;
    --primary-lighter: #e8f0fe;
    --accent: #1a73e8;
    --accent-warm: #ff6b35;
    --bg: #f6f8fa;
    --bg-white: #ffffff;
    --text-primary: #24292e;
    --text-secondary: #586069;
    --text-light: #959da5;
    --border: #e1e4e8;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.12);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --header-height: 72px;
}

/* --- Reset --- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    color: var(--text-primary);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul, ol {
    list-style: none;
}

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

/* --- Container --- */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.section {
    padding: 50px 0;
}

/* --- Section Title --- */
.section-title {
    text-align: center;
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.title-line {
    width: 40px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--primary-light));
    border-radius: 2px;
}

.section-title-sm {
    justify-content: flex-start;
    margin-bottom: 24px;
    font-size: 1.35rem;
}

.more-link {
    font-size: 0.875rem;
    color: var(--primary);
    font-weight: 500;
    margin-left: auto;
    padding: 4px 12px;
    border-radius: 20px;
    background: var(--primary-lighter);
}

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

/* ============================================
   Header
   ============================================ */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: var(--transition);
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo-link {
    flex-shrink: 0;
}

.logo {
    height: 48px;
    width: auto;
}

/* Desktop Nav */
.nav-desktop ul {
    display: flex;
    gap: 8px;
}

.nav-desktop a {
    display: block;
    padding: 8px 16px;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    position: relative;
}

.nav-desktop a::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 60%;
    height: 2px;
    background: var(--primary);
    border-radius: 1px;
    transition: transform 0.3s ease;
}

.nav-desktop a:hover,
.nav-desktop a.active {
    color: var(--primary);
}

.nav-desktop a:hover::after,
.nav-desktop a.active::after {
    transform: translateX(-50%) scaleX(1);
}

/* Hamburger */
.hamburger {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    background: none;
    border: none;
    cursor: pointer;
    gap: 5px;
    padding: 0;
}

.hamburger span {
    display: block;
    width: 24px;
    height: 2.5px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition);
}

/* Mobile Menu */
.mobile-menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}

.mobile-menu-overlay.active {
    opacity: 1;
    visibility: visible;
}

.mobile-menu {
    position: fixed;
    top: 0;
    right: -300px;
    width: 280px;
    height: 100%;
    background: var(--bg-white);
    z-index: 2001;
    padding: 24px;
    transition: right 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: -4px 0 20px rgba(0,0,0,0.15);
}

.mobile-menu-overlay.active .mobile-menu {
    right: 0;
}

.menu-close {
    position: absolute;
    top: 16px;
    right: 16px;
    width: 36px;
    height: 36px;
    background: var(--bg);
    border: none;
    border-radius: 50%;
    font-size: 1.25rem;
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.menu-close:hover {
    background: var(--primary-lighter);
    color: var(--primary);
}

.mobile-menu ul {
    margin-top: 60px;
}

.mobile-menu li {
    border-bottom: 1px solid var(--border);
}

.mobile-menu a {
    display: block;
    padding: 14px 0;
    font-size: 1.05rem;
    font-weight: 500;
    color: var(--text-primary);
}

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

/* ============================================
   Footer
   ============================================ */
.footer {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    color: #fff;
    margin-top: 40px;
}

.footer-container {
    display: flex;
    align-items: flex-start;
    gap: 40px;
    padding: 40px 20px;
}

.footer-col h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 16px;
    position: relative;
    padding-bottom: 8px;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 30px;
    height: 2px;
    background: rgba(255,255,255,0.6);
    border-radius: 1px;
}

.footer-contact p {
    font-size: 0.875rem;
    margin-bottom: 8px;
    opacity: 0.9;
    line-height: 1.8;
}

.footer-links ul li {
    margin-bottom: 8px;
}

.footer-links a {
    font-size: 0.875rem;
    opacity: 0.85;
    position: relative;
    padding-left: 0;
    transition: var(--transition);
}

.footer-links a::before {
    content: '›';
    margin-right: 6px;
    opacity: 0;
    transform: translateX(-4px);
    display: inline-block;
    transition: var(--transition);
}

.footer-links a:hover {
    opacity: 1;
    padding-left: 4px;
}

.footer-links a:hover::before {
    opacity: 1;
    transform: translateX(0);
}

.qr-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.qr-img {
    width: 100px;
    height: 112px;
    object-fit: cover;
    border-radius: var(--radius-sm);
    background: #fff;
    transition: var(--transition);
}

.qr-img:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
}

.footer-copyright {
    text-align: center;
    padding: 16px 20px;
    background: rgba(0,0,0,0.15);
    font-size: 0.8rem;
    opacity: 0.8;
}

/* ============================================
   Breadcrumb
   ============================================ */
.breadcrumb-bar {
    margin-top: var(--header-height);
    padding: 14px 0;
    background: var(--bg-white);
    border-bottom: 1px solid var(--border);
}

.breadcrumb a {
    color: var(--primary);
    font-size: 0.875rem;
}

.breadcrumb a:hover {
    text-decoration: underline;
}

.breadcrumb {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* ============================================
   Responsive - Tablet (≤960px)
   ============================================ */
@media (max-width: 960px) {
    .nav-desktop {
        display: none;
    }

    .hamburger {
        display: flex;
    }

    .logo {
        height: 40px;
    }

    .footer-container {
        flex-direction: column;
        align-items: center;
        text-align: center;
        gap: 30px;
    }

    .footer-col h4::after {
        left: 50%;
        transform: translateX(-50%);
    }

    .qr-grid {
        justify-content: center;
    }
}

/* ============================================
   Responsive - Mobile (≤640px)
   ============================================ */
@media (max-width: 640px) {
    :root {
        --header-height: 60px;
    }

    .logo {
        height: 34px;
    }

    .section {
        padding: 36px 0;
    }

    .section-title {
        font-size: 1.35rem;
        margin-bottom: 28px;
    }

    .footer-container {
        padding: 30px 16px;
    }
}