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

:root {
    --color-bg: #f5f3ef;
    --color-bg-soft: #ebe7df;
    --color-ink: #1a1a1a;
    --color-ink-soft: #4a4a4a;
    --color-muted: #8a8a8a;
    --color-line: #d6d1c4;
    --color-accent: #c8553d;
    --color-accent-dark: #9b3d2a;
    --color-paper: #ffffff;
    --color-dark: #1a1a1a;
    --shadow-sm: 0 1px 2px rgba(26,26,26,0.06), 0 2px 6px rgba(26,26,26,0.04);
    --shadow-md: 0 4px 12px rgba(26,26,26,0.08), 0 8px 24px rgba(26,26,26,0.06);
    --shadow-lg: 0 12px 32px rgba(26,26,26,0.12), 0 24px 60px rgba(26,26,26,0.08);
    --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
    --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    --radius-sm: 2px;
    --radius-md: 4px;
    --transition: 0.4s cubic-bezier(0.22, 0.61, 0.36, 1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    line-height: 1.7;
    color: var(--color-ink);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 32px;
}

/* ========== 导航栏 ========== */
.navbar {
    background: var(--color-paper);
    border-bottom: 1px solid var(--color-line);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: saturate(180%) blur(8px);
    -webkit-backdrop-filter: saturate(180%) blur(8px);
}

.nav-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 32px;
    display: flex;
    justify-content: space-between;
    align-items: stretch;
    height: 88px;
}

.nav-logo {
    display: flex;
    align-items: center;
    position: relative;
}

.nav-logo h2 {
    color: var(--color-ink);
    font-family: var(--font-serif);
    font-size: 1.4rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    padding-left: 16px;
    border-left: 3px solid var(--color-accent);
    line-height: 1.2;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 0;
    align-items: stretch;
}

.nav-item {
    display: flex;
    align-items: stretch;
}

.nav-link {
    text-decoration: none;
    color: var(--color-ink-soft);
    font-weight: 400;
    font-size: 0.95rem;
    letter-spacing: 0.1em;
    padding: 0 22px;
    display: flex;
    align-items: center;
    position: relative;
    transition: color var(--transition);
}

.nav-link::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: width var(--transition);
}

.nav-link:hover {
    color: var(--color-ink);
}

.nav-link:hover::before,
.nav-link.active::before {
    width: 60%;
}

.nav-link.active {
    color: var(--color-accent);
    font-weight: 500;
}

/* ========== Banner ========== */
.banner {
    margin-bottom: 80px;
    position: relative;
    overflow: hidden;
}

.banner img {
    display: block;
    width: 100%;
    height: auto;
    object-fit: cover;
}

/* ========== 按钮 ========== */
.btn-primary {
    background: var(--color-accent);
    color: #fff;
    padding: 14px 36px;
    border: none;
    border-radius: var(--radius-sm);
    text-decoration: none;
    font-weight: 500;
    letter-spacing: 0.1em;
    transition: all var(--transition);
    cursor: pointer;
    display: inline-block;
    font-size: 0.9rem;
    position: relative;
    overflow: hidden;
}

.btn-primary::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    transition: left 0.6s;
}

.btn-primary:hover {
    background: var(--color-accent-dark);
    transform: translateY(-1px);
    box-shadow: 0 8px 20px rgba(200, 85, 61, 0.25);
}

.btn-primary:hover::after {
    left: 100%;
}

/* ========== 分区标题 ========== */
.section-title {
    text-align: center;
    font-family: var(--font-serif);
    font-size: 2.2rem;
    font-weight: 500;
    margin-bottom: 60px;
    color: var(--color-ink);
    letter-spacing: 0.15em;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
}

.section-title::before,
.section-title::after {
    content: '';
    width: 40px;
    height: 1px;
    background: var(--color-accent);
    display: inline-block;
}

.section-title .title-en {
    display: block;
    font-family: var(--font-sans);
    font-size: 0.75rem;
    color: var(--color-muted);
    letter-spacing: 0.4em;
    margin-top: 8px;
    text-transform: uppercase;
}

/* ========== 热门信息 ========== */
.featured-products {
    padding: 40px 0 100px;
    position: relative;
}

.featured-products::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 1px;
    height: 40px;
    background: var(--color-line);
}

/* ========== 商品网格 ========== */
.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
    margin-bottom: 60px;
}

.product-card {
    background: var(--color-paper);
    border: 1px solid var(--color-line);
    overflow: hidden;
    transition: all var(--transition);
    position: relative;
    cursor: pointer;
}

.product-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--color-accent);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition);
    z-index: 2;
}

.product-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

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

.product-image {
    width: 100%;
    height: 240px;
    object-fit: cover;
    transition: transform 0.6s ease;
    display: block;
}

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

.product-image-wrapper {
    overflow: hidden;
    position: relative;
    background: var(--color-bg-soft);
}

.product-info {
    padding: 24px 22px 22px;
    border-top: 1px solid transparent;
    position: relative;
}

.product-title {
    font-size: 1.05rem;
    font-weight: 500;
    margin-bottom: 14px;
    color: var(--color-ink);
    display: -webkit-box;
    -webkit-line-clamp: 1;
    -webkit-box-orient: vertical;
    overflow: hidden;
    text-overflow: ellipsis;
    font-family: var(--font-serif);
    letter-spacing: 0.03em;
}

.product-price {
    font-size: 1.4rem;
    color: var(--color-accent);
    font-weight: 600;
    margin-bottom: 12px;
    font-family: var(--font-serif);
    letter-spacing: 0.02em;
}

.product-price::before {
    content: '¥';
    font-size: 0.85em;
    margin-right: 2px;
    font-weight: 400;
}

.product-condition {
    color: var(--color-muted);
    margin-bottom: 14px;
    font-size: 0.85rem;
    display: inline-block;
    padding: 2px 10px;
    background: var(--color-bg-soft);
    border-radius: 2px;
}

.product-seller {
    color: var(--color-muted);
    font-size: 0.8rem;
    letter-spacing: 0.05em;
    padding-top: 12px;
    border-top: 1px dashed var(--color-line);
    display: flex;
    align-items: center;
    gap: 6px;
}

.product-seller::before {
    content: '·';
    color: var(--color-accent);
    font-weight: bold;
    font-size: 1.2em;
    line-height: 0;
}

/* ========== 分类网格 ========== */
.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
    margin-bottom: 60px;
}

.category-card {
    background: var(--color-paper);
    padding: 48px 24px;
    border: 1px solid var(--color-line);
    text-align: center;
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
}

.category-card::after {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 60px;
    height: 60px;
    background: var(--color-accent);
    transform: translate(50%, -50%) rotate(45deg);
    opacity: 0;
    transition: opacity var(--transition);
}

.category-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--color-accent);
}

.category-card:hover::after {
    opacity: 0.08;
}

.category-icon {
    font-size: 3.2rem;
    margin-bottom: 20px;
    display: inline-block;
    transition: transform var(--transition);
}

.category-card:hover .category-icon {
    transform: rotate(-8deg) scale(1.05);
}

.category-card h3 {
    font-size: 1.25rem;
    margin-bottom: 10px;
    color: var(--color-ink);
    font-family: var(--font-serif);
    font-weight: 500;
    letter-spacing: 0.05em;
}

.category-card p {
    color: var(--color-muted);
    font-size: 0.88rem;
    line-height: 1.6;
}

.category-card a {
    text-decoration: none;
    color: inherit;
    display: block;
}

/* ========== 页面头部 ========== */
.page-header {
    background: var(--color-dark);
    color: #fff;
    padding: 90px 0 80px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.page-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(circle at 20% 30%, rgba(200, 85, 61, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(200, 85, 61, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.page-header::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--color-accent) 50%, transparent);
}

.page-header .container {
    position: relative;
    z-index: 1;
}

.page-header h1 {
    font-size: 2.6rem;
    margin-bottom: 12px;
    font-family: var(--font-serif);
    font-weight: 500;
    letter-spacing: 0.2em;
    position: relative;
    display: inline-block;
    padding-bottom: 16px;
}

.page-header h1::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 30px;
    height: 2px;
    background: var(--color-accent);
}

.page-header h1::before {
    content: '';
    display: block;
    font-family: var(--font-sans);
    font-size: 0.7rem;
    color: var(--color-muted);
    letter-spacing: 0.5em;
    margin-bottom: 14px;
    text-transform: uppercase;
    font-weight: 400;
}

/* ========== 详情页 ========== */
.detail-container {
    background: var(--color-paper);
    border: 1px solid var(--color-line);
    padding: 56px;
    margin: 60px 0;
    position: relative;
}

.detail-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 80px;
    height: 80px;
    border-top: 2px solid var(--color-accent);
    border-left: 2px solid var(--color-accent);
    pointer-events: none;
}

.detail-container::after {
    content: '';
    position: absolute;
    bottom: 0;
    right: 0;
    width: 80px;
    height: 80px;
    border-bottom: 2px solid var(--color-accent);
    border-right: 2px solid var(--color-accent);
    pointer-events: none;
}

.product-images {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 16px;
    margin-bottom: 40px;
}

.product-images img {
    object-fit: cover;
    border: 1px solid var(--color-line);
    transition: all var(--transition);
    cursor: pointer;
}

.product-images img:hover {
    transform: scale(1.02);
    box-shadow: var(--shadow-md);
    border-color: var(--color-accent);
}

.detail-info h1 {
    font-size: 2.2rem;
    margin-bottom: 20px;
    color: var(--color-ink);
    font-family: var(--font-serif);
    font-weight: 500;
    letter-spacing: 0.05em;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--color-line);
}

.detail-price {
    font-size: 2.4rem;
    color: var(--color-accent);
    font-weight: 600;
    margin-bottom: 30px;
    font-family: var(--font-serif);
    letter-spacing: 0.02em;
}

.detail-price::before {
    content: '¥';
    font-size: 0.7em;
    margin-right: 4px;
    font-weight: 400;
}

.detail-meta {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 40px;
}

.meta-item {
    background: var(--color-bg);
    padding: 20px;
    border-left: 2px solid var(--color-accent);
    transition: all var(--transition);
}

.meta-item:hover {
    background: var(--color-bg-soft);
    transform: translateX(2px);
}

.meta-item strong {
    color: var(--color-ink);
    display: block;
    font-size: 0.75rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    margin-bottom: 6px;
    color: var(--color-muted);
    font-weight: 500;
}

.detail-description {
    line-height: 1.9;
    margin-bottom: 40px;
    color: var(--color-ink-soft);
    font-size: 1rem;
}

.seller-info {
    background: var(--color-bg);
    padding: 24px 28px;
    border-left: 3px solid var(--color-accent);
    position: relative;
}

.seller-info::before {
    content: '发布人信息';
    position: absolute;
    top: -10px;
    left: 20px;
    background: var(--color-paper);
    padding: 0 10px;
    font-size: 0.7rem;
    color: var(--color-accent);
    letter-spacing: 0.2em;
    text-transform: uppercase;
}

/* ========== 表单 ========== */
.publish-section,
.auth-section {
    padding: 80px 0;
}

.auth-container {
    max-width: 440px;
    margin: 0 auto;
    background: var(--color-paper);
    padding: 56px 48px;
    border: 1px solid var(--color-line);
    position: relative;
}

.auth-container::before {
    content: '';
    position: absolute;
    top: -1px;
    left: -1px;
    right: -1px;
    height: 4px;
    background: var(--color-accent);
}

.publish-form,
.auth-form {
    max-width: 640px;
    margin: 0 auto;
    background: var(--color-paper);
    padding: 56px;
    border: 1px solid var(--color-line);
    position: relative;
}

.publish-form::before,
.auth-form::before {
    content: '';
    position: absolute;
    top: -1px;
    left: -1px;
    right: -1px;
    height: 4px;
    background: var(--color-accent);
}

.form-group {
    margin-bottom: 28px;
}

.form-group label {
    display: block;
    margin-bottom: 10px;
    font-weight: 500;
    color: var(--color-ink);
    font-size: 0.85rem;
    letter-spacing: 0.1em;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid var(--color-line);
    border-radius: 0;
    font-size: 0.95rem;
    background: var(--color-bg);
    color: var(--color-ink);
    transition: all var(--transition);
    font-family: var(--font-sans);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-accent);
    background: var(--color-paper);
    box-shadow: 0 0 0 3px rgba(200, 85, 61, 0.1);
}

.form-group small {
    color: var(--color-muted);
    font-size: 0.8rem;
    margin-top: 6px;
    display: block;
}

.auth-links {
    text-align: center;
    margin-top: 28px;
    padding-top: 24px;
    border-top: 1px solid var(--color-line);
}

.auth-links a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--transition);
    letter-spacing: 0.05em;
}

.auth-links a:hover {
    color: var(--color-accent-dark);
    text-decoration: underline;
}

/* ========== 页脚 ========== */
.footer {
    background: var(--color-dark);
    color: rgba(255,255,255,0.7);
    text-align: center;
    padding: 60px 0;
    margin-top: 80px;
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--color-accent) 50%, transparent);
}

.footer .container {
    position: relative;
}

.footer p {
    margin-bottom: 8px;
    font-size: 0.9rem;
    letter-spacing: 0.05em;
    line-height: 1.8;
}

.footer p:first-child {
    font-family: var(--font-serif);
    color: #fff;
    font-size: 1.1rem;
    margin-bottom: 16px;
    letter-spacing: 0.1em;
}

.footer a {
    color: rgba(255,255,255,0.6);
    text-decoration: none;
    transition: color var(--transition);
    border-bottom: 1px dotted rgba(255,255,255,0.3);
    padding-bottom: 2px;
    margin: 30px;
}

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

/* ========== 响应式 ========== */
@media (max-width: 768px) {
    .container {
        padding: 0 20px;
    }

    .nav-container {
        flex-direction: column;
        height: auto;
        padding: 20px;
        gap: 16px;
    }

    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
        gap: 0;
    }

    .nav-link {
        padding: 8px 14px;
        font-size: 0.85rem;
    }

    .banner {
        margin-bottom: 50px;
    }

    .section-title {
        font-size: 1.6rem;
        gap: 12px;
    }

    .section-title::before,
    .section-title::after {
        width: 24px;
    }

    .products-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .page-header {
        padding: 60px 0 50px;
    }

    .page-header h1 {
        font-size: 1.8rem;
    }

    .detail-container {
        padding: 28px 20px;
        margin: 30px 0;
    }

    .detail-container::before,
    .detail-container::after {
        width: 40px;
        height: 40px;
    }

    .auth-container,
    .publish-form,
    .auth-form {
        padding: 32px 24px;
        margin: 0 20px;
    }

    .featured-products {
        padding-bottom: 60px;
    }
}

/* ========== 工具类 ========== */
.loading {
    text-align: center;
    padding: 60px 20px;
    color: var(--color-muted);
    font-size: 0.9rem;
    letter-spacing: 0.1em;
}

.loading::after {
    content: '...';
    display: inline-block;
    animation: dots 1.4s infinite;
}

@keyframes dots {
    0%, 20% { content: '.'; }
    40% { content: '..'; }
    60%, 100% { content: '...'; }
}

.error-message {
    background: var(--color-accent);
    color: white;
    padding: 14px 20px;
    border-radius: var(--radius-sm);
    margin-bottom: 24px;
    text-align: center;
    font-size: 0.9rem;
    letter-spacing: 0.05em;
    border-left: 4px solid var(--color-accent-dark);
}

.success-message {
    background: #2d5a3d;
    color: white;
    padding: 14px 20px;
    border-radius: var(--radius-sm);
    margin-bottom: 24px;
    text-align: center;
    font-size: 0.9rem;
    letter-spacing: 0.05em;
    border-left: 4px solid #1f3f2a;
}

/* ========== 微交互 ========== */
::selection {
    background: var(--color-accent);
    color: #fff;
}

::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg);
}

::-webkit-scrollbar-thumb {
    background: var(--color-line);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-accent);
}