/* =========================================
   51吃瓜 · 复古摄影·怀旧胶片·文艺摄影美学
   外部CSS文件
   ========================================= */

/* CSS变量 */
:root {
    --cream: #fdfbf7;
    --beige: #f0e8d8;
    --dark-brown: #3b312a;
    --warm-orange: #d97742;
    --dark-red: #8b2e25;
    --light-gray: #a9a297;
    --border: #d3c9b8;
    --white: #ffffff;
    --shadow: rgba(59, 49, 42, 0.15);
    --font-serif: "Georgia", "SimSun", "宋体", serif;
    --font-mono: "Courier New", Courier, monospace;
    --font-sans: "Microsoft YaHei", "微软雅黑", "PingFang SC", sans-serif;
    --transition: 0.3s ease;
    --radius: 2px;
}

/* 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-sans);
    background-color: var(--cream);
    color: var(--dark-brown);
    line-height: 1.7;
    overflow-x: hidden;
}

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

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

a:hover {
    color: var(--warm-orange);
}

ul {
    list-style: none;
}

/* =========================================
   容器
   ========================================= */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* =========================================
   按钮
   ========================================= */
.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    font-family: var(--font-serif);
    font-size: 1rem;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all var(--transition);
    text-align: center;
    letter-spacing: 0.05em;
}

.btn-primary {
    background-color: var(--dark-red);
    color: var(--white);
    border-color: var(--dark-red);
}

.btn-primary:hover {
    background-color: var(--warm-orange);
    border-color: var(--warm-orange);
    color: var(--white);
}

.btn-secondary {
    background-color: transparent;
    color: var(--white);
    border-color: var(--white);
}

.btn-secondary:hover {
    background-color: var(--white);
    color: var(--dark-red);
}

.btn-outline {
    background-color: transparent;
    color: var(--dark-red);
    border-color: var(--dark-red);
}

.btn-outline:hover {
    background-color: var(--dark-red);
    color: var(--white);
}

/* =========================================
   顶部导航
   ========================================= */
.site-header {
    background-color: rgba(253, 251, 247, 0.97);
    border-bottom: 2px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 8px var(--shadow);
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0.8rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.logo-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--dark-brown);
}

.logo-link:hover {
    color: var(--dark-red);
}

.logo-img {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 2px solid var(--border);
    object-fit: cover;
}

.logo-text {
    font-family: var(--font-serif);
    font-size: 1.6rem;
    font-weight: bold;
    color: var(--dark-red);
    letter-spacing: 0.1em;
}

.main-nav ul {
    display: flex;
    gap: 0.25rem;
    flex-wrap: wrap;
}

.main-nav a {
    display: block;
    padding: 0.4rem 0.75rem;
    font-size: 0.9rem;
    color: var(--dark-brown);
    font-weight: 500;
    border-bottom: 2px solid transparent;
    transition: all var(--transition);
}

.main-nav a:hover,
.main-nav a.active {
    color: var(--dark-red);
    border-bottom-color: var(--dark-red);
}

.nav-toggle {
    display: none;
    background: none;
    border: 1px solid var(--border);
    padding: 0.4rem 0.6rem;
    font-size: 1.2rem;
    cursor: pointer;
    color: var(--dark-brown);
}

/* 搜索框 */
.search-bar {
    background-color: var(--beige);
    border-bottom: 1px solid var(--border);
    padding: 0.5rem 1.5rem;
}

.search-inner {
    max-width: 600px;
    margin: 0 auto;
    display: flex;
    border: 1px solid var(--border);
    background-color: var(--white);
    overflow: hidden;
}

.search-inner input {
    flex: 1;
    padding: 0.6rem 1rem;
    border: none;
    outline: none;
    font-family: var(--font-sans);
    font-size: 0.95rem;
    background: transparent;
    color: var(--dark-brown);
}

.search-inner input::placeholder {
    color: var(--light-gray);
}

.search-inner button {
    padding: 0.6rem 1rem;
    background-color: var(--dark-red);
    border: none;
    cursor: pointer;
    color: var(--white);
    transition: background-color var(--transition);
    display: flex;
    align-items: center;
}

.search-inner button:hover {
    background-color: var(--warm-orange);
}

/* =========================================
   首屏Banner
   ========================================= */
.hero-banner {
    position: relative;
    overflow: hidden;
    max-height: 600px;
}

.film-frame {
    position: relative;
    overflow: hidden;
}

.banner-img {
    width: 100%;
    height: 600px;
    object-fit: cover;
    filter: sepia(0.25) contrast(1.1) brightness(0.9);
    display: block;
}

/* 胶片颗粒效果 */
.film-grain {
    position: absolute;
    inset: 0;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.08'/%3E%3C/svg%3E");
    background-size: 200px 200px;
    opacity: 0.4;
    pointer-events: none;
    mix-blend-mode: multiply;
}

/* 暗角效果 */
.vignette {
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at center, transparent 50%, rgba(30, 20, 10, 0.6) 100%);
    pointer-events: none;
}

.banner-overlay {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.banner-content {
    text-align: center;
    padding: 2.5rem 3rem;
    background-color: rgba(253, 251, 247, 0.85);
    border: 1px solid rgba(211, 201, 184, 0.8);
    max-width: 600px;
    backdrop-filter: blur(2px);
}

.brand-tagline {
    font-family: var(--font-serif);
    font-size: 2rem;
    color: var(--dark-red);
    margin-bottom: 0.75rem;
    line-height: 1.3;
}

.brand-sub {
    font-size: 1rem;
    color: var(--light-gray);
    margin-bottom: 1.5rem;
    letter-spacing: 0.1em;
}

.banner-btns {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.banner-btns .btn-secondary {
    color: var(--dark-red);
    border-color: var(--dark-red);
}

.banner-btns .btn-secondary:hover {
    background-color: var(--dark-red);
    color: var(--white);
}

/* =========================================
   通用Section样式
   ========================================= */
.section {
    padding: 5rem 0;
}

.section:nth-child(even) {
    background-color: var(--beige);
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-title {
    font-family: var(--font-serif);
    font-size: 1.9rem;
    color: var(--dark-red);
    margin-bottom: 0.75rem;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    display: block;
    width: 60%;
    height: 2px;
    background-color: var(--warm-orange);
    margin: 0.5rem auto 0;
}

.section-desc {
    color: var(--light-gray);
    font-size: 1rem;
    max-width: 600px;
    margin: 0 auto;
}

.section-more {
    text-align: center;
    margin-top: 2.5rem;
}

/* =========================================
   视频卡片
   ========================================= */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 2rem;
}

.video-card {
    background-color: var(--white);
    border: 1px solid var(--border);
    overflow: hidden;
    transition: transform var(--transition), box-shadow var(--transition);
}

.video-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 30px var(--shadow);
}

.video-thumb-wrap {
    position: relative;
    overflow: hidden;
    cursor: pointer;
    aspect-ratio: 4/3;
}

.video-thumb-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: filter 0.5s ease, transform 0.5s ease;
}

/* 悬停胶片颗粒抖动、暗角晕染与老照片光晕过渡效果 */
.video-thumb-wrap:hover img {
    filter: sepia(0.6) contrast(1.4) brightness(0.75) saturate(0.8);
    animation: film-shake 0.08s infinite;
}

.film-overlay {
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at center, transparent 40%, rgba(20, 10, 5, 0.5) 100%);
    opacity: 0;
    transition: opacity 0.4s ease;
    pointer-events: none;
}

.video-thumb-wrap:hover .film-overlay {
    opacity: 1;
}

/* 老照片光晕效果 */
.video-thumb-wrap::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 30% 30%, rgba(255, 220, 150, 0.15) 0%, transparent 60%);
    opacity: 0;
    transition: opacity 0.4s ease;
    pointer-events: none;
}

.video-thumb-wrap:hover::after {
    opacity: 1;
}

.play-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0.8);
    width: 60px;
    height: 60px;
    opacity: 0;
    transition: opacity 0.3s ease, transform 0.3s ease;
    pointer-events: none;
}

.video-thumb-wrap:hover .play-icon {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1);
}

.video-tag {
    position: absolute;
    top: 0.75rem;
    right: 0.75rem;
    background-color: var(--dark-red);
    color: var(--white);
    font-size: 0.75rem;
    padding: 0.2rem 0.6rem;
    letter-spacing: 0.05em;
}

.video-info {
    padding: 1.25rem;
}

.video-info h3 {
    font-family: var(--font-serif);
    font-size: 1rem;
    color: var(--dark-brown);
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.video-desc {
    font-size: 0.875rem;
    color: var(--light-gray);
    margin-bottom: 0.75rem;
    line-height: 1.5;
}

.video-meta {
    display: flex;
    gap: 1rem;
    font-size: 0.8rem;
    color: var(--light-gray);
    flex-wrap: wrap;
}

/* 胶片抖动动画 */
@keyframes film-shake {
    0%   { transform: translate(0, 0) scale(1.02); }
    25%  { transform: translate(1px, 1px) scale(1.02); }
    50%  { transform: translate(-1px, 0px) scale(1.02); }
    75%  { transform: translate(0px, -1px) scale(1.02); }
    100% { transform: translate(1px, 0px) scale(1.02); }
}

/* =========================================
   品牌故事模块
   ========================================= */
.story-section {
    background-color: var(--beige);
}

.story-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.story-text h2 {
    text-align: left;
}

.story-text h2::after {
    margin-left: 0;
}

.story-text h3 {
    font-family: var(--font-serif);
    font-size: 1.2rem;
    color: var(--warm-orange);
    margin: 1rem 0;
}

.story-text p {
    margin-bottom: 1rem;
    color: var(--dark-brown);
    line-height: 1.8;
}

.story-text .btn {
    margin-top: 1rem;
}

.story-img img {
    width: 100%;
    border: 8px solid var(--white);
    box-shadow: 0 8px 24px var(--shadow);
    filter: sepia(0.15);
}

/* =========================================
   图片墙
   ========================================= */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.gallery-item {
    position: relative;
    overflow: hidden;
    cursor: pointer;
}

.gallery-item img {
    width: 100%;
    aspect-ratio: 4/3;
    object-fit: cover;
    border: 6px solid var(--white);
    box-shadow: 0 4px 12px var(--shadow);
    filter: sepia(0.2) contrast(1.05);
    transition: filter var(--transition), transform var(--transition);
}

.gallery-item:hover img {
    filter: sepia(0.4) contrast(1.2) brightness(0.85);
    transform: scale(1.03);
}

.gallery-caption {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(transparent, rgba(30, 20, 10, 0.7));
    color: var(--white);
    padding: 1.5rem 1rem 0.75rem;
    font-size: 0.9rem;
    font-family: var(--font-serif);
    opacity: 0;
    transition: opacity var(--transition);
}

.gallery-item:hover .gallery-caption {
    opacity: 1;
}

/* =========================================
   AI工具模块
   ========================================= */
.ai-features {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 1.5rem;
}

.ai-feature-card {
    background-color: var(--white);
    border: 1px solid var(--border);
    padding: 2rem 1.5rem;
    text-align: center;
    transition: transform var(--transition), box-shadow var(--transition);
}

.ai-feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px var(--shadow);
}

.ai-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.ai-feature-card h3 {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    color: var(--dark-red);
    margin-bottom: 0.75rem;
}

.ai-feature-card p {
    font-size: 0.9rem;
    color: var(--light-gray);
    line-height: 1.6;
}

/* =========================================
   达人模块
   ========================================= */
.creators-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

.creator-card {
    background-color: var(--white);
    border: 1px solid var(--border);
    overflow: hidden;
    transition: transform var(--transition), box-shadow var(--transition);
}

.creator-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px var(--shadow);
}

.creator-card img {
    width: 100%;
    aspect-ratio: 4/3;
    object-fit: cover;
    filter: sepia(0.2);
    transition: filter var(--transition);
}

.creator-card:hover img {
    filter: sepia(0.1);
}

.creator-card h3 {
    font-family: var(--font-serif);
    font-size: 1.2rem;
    color: var(--dark-red);
    padding: 1rem 1.25rem 0.25rem;
}

.creator-title {
    font-size: 0.85rem;
    color: var(--warm-orange);
    padding: 0 1.25rem 0.5rem;
}

.creator-desc {
    font-size: 0.9rem;
    color: var(--light-gray);
    padding: 0 1.25rem;
    line-height: 1.6;
}

.creator-stats {
    display: flex;
    gap: 1.5rem;
    padding: 0.75rem 1.25rem 1.25rem;
    font-size: 0.85rem;
    color: var(--light-gray);
}

/* =========================================
   用户评价
   ========================================= */
.reviews-section {
    background-color: var(--beige);
}

.reviews-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.review-card {
    background-color: var(--white);
    border-left: 4px solid var(--warm-orange);
    padding: 1.5rem;
    font-style: italic;
    color: var(--dark-brown);
    line-height: 1.7;
    box-shadow: 0 2px 8px var(--shadow);
}

.review-card p {
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.review-card footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-style: normal;
    font-size: 0.85rem;
}

.review-card cite {
    color: var(--light-gray);
}

.stars {
    color: var(--warm-orange);
    letter-spacing: 0.1em;
}

/* =========================================
   FAQ模块
   ========================================= */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border-bottom: 1px solid var(--border);
    overflow: hidden;
}

.faq-q {
    font-family: var(--font-serif);
    font-size: 1.05rem;
    color: var(--dark-brown);
    padding: 1.25rem 1rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: color var(--transition);
}

.faq-q::after {
    content: '+';
    font-size: 1.4rem;
    color: var(--warm-orange);
    transition: transform var(--transition);
    flex-shrink: 0;
    margin-left: 1rem;
}

.faq-item.active .faq-q {
    color: var(--dark-red);
}

.faq-item.active .faq-q::after {
    transform: rotate(45deg);
}

.faq-a {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
}

.faq-item.active .faq-a {
    max-height: 300px;
}

.faq-a p {
    padding: 0 1rem 1.25rem;
    color: var(--light-gray);
    line-height: 1.7;
    font-size: 0.95rem;
}

/* =========================================
   联系模块
   ========================================= */
.contact-section {
    background-color: var(--beige);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: start;
}

.contact-info h3 {
    font-family: var(--font-serif);
    font-size: 1.3rem;
    color: var(--dark-red);
    margin-bottom: 1.25rem;
}

.contact-info p {
    margin-bottom: 0.75rem;
    font-size: 0.95rem;
    color: var(--dark-brown);
}

.contact-info strong {
    color: var(--dark-red);
}

.contact-qr {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.qr-placeholder {
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
    justify-content: center;
}

.qr-box {
    width: 120px;
    height: 120px;
    border: 2px dashed var(--border);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    font-size: 0.8rem;
    color: var(--light-gray);
    background-color: var(--white);
}

/* =========================================
   内页栏目入口
   ========================================= */
.inner-pages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1.5rem;
}

.inner-page-card {
    display: block;
    background-color: var(--white);
    border: 1px solid var(--border);
    padding: 1.75rem 1.25rem;
    text-align: center;
    color: var(--dark-brown);
    transition: all var(--transition);
}

.inner-page-card:hover {
    background-color: var(--dark-red);
    color: var(--white);
    transform: translateY(-4px);
    box-shadow: 0 8px 20px var(--shadow);
}

.inner-page-card h3 {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    color: var(--dark-red);
    margin-bottom: 0.75rem;
    transition: color var(--transition);
}

.inner-page-card:hover h3 {
    color: var(--white);
}

.inner-page-card p {
    font-size: 0.85rem;
    color: var(--light-gray);
    line-height: 1.5;
    transition: color var(--transition);
}

.inner-page-card:hover p {
    color: rgba(255, 255, 255, 0.85);
}

/* =========================================
   页脚
   ========================================= */
.site-footer {
    background-color: var(--dark-brown);
    color: var(--beige);
    padding: 3rem 0 1.5rem;
}

.footer-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: grid;
    grid-template-columns: auto 1fr 1fr 2fr;
    gap: 3rem;
    align-items: start;
}

.footer-logo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
}

.footer-logo img {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    border: 2px solid rgba(211, 201, 184, 0.4);
    object-fit: cover;
}

.footer-logo span {
    font-family: var(--font-serif);
    font-size: 1.2rem;
    color: var(--warm-orange);
}

.footer-links h4 {
    font-family: var(--font-serif);
    font-size: 1rem;
    color: var(--warm-orange);
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid rgba(211, 201, 184, 0.2);
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.footer-links a {
    font-size: 0.875rem;
    color: rgba(240, 232, 216, 0.7);
    transition: color var(--transition);
}

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

.footer-info {
    font-size: 0.875rem;
    color: rgba(240, 232, 216, 0.7);
    line-height: 1.8;
}

.footer-info p {
    margin-bottom: 0.4rem;
}

.social-share {
    margin-top: 1rem;
    display: flex;
    gap: 0.75rem;
    align-items: center;
    flex-wrap: wrap;
}

.social-share a {
    color: var(--warm-orange);
    font-size: 0.875rem;
    padding: 0.2rem 0.6rem;
    border: 1px solid rgba(217, 119, 66, 0.4);
    transition: all var(--transition);
}

.social-share a:hover {
    background-color: var(--warm-orange);
    color: var(--white);
}

/* =========================================
   内页通用样式
   ========================================= */
.page-hero {
    background-color: var(--beige);
    padding: 4rem 0 3rem;
    text-align: center;
    border-bottom: 2px solid var(--border);
}

.page-hero h1 {
    font-family: var(--font-serif);
    font-size: 2.2rem;
    color: var(--dark-red);
    margin-bottom: 0.75rem;
}

.page-hero p {
    color: var(--light-gray);
    max-width: 600px;
    margin: 0 auto;
}

.breadcrumb {
    font-size: 0.85rem;
    color: var(--light-gray);
    margin-bottom: 1rem;
}

.breadcrumb a {
    color: var(--light-gray);
}

.breadcrumb a:hover {
    color: var(--dark-red);
}

/* =========================================
   响应式设计
   ========================================= */
@media (max-width: 1024px) {
    .footer-inner {
        grid-template-columns: 1fr 1fr;
    }
    
    .story-layout {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

@media (max-width: 768px) {
    .header-inner {
        flex-wrap: wrap;
    }
    
    .main-nav {
        display: none;
        width: 100%;
        order: 3;
    }
    
    .main-nav.open {
        display: block;
    }
    
    .main-nav ul {
        flex-direction: column;
        gap: 0;
    }
    
    .main-nav a {
        padding: 0.75rem 1rem;
        border-bottom: 1px solid var(--border);
        border-left: none;
    }
    
    .nav-toggle {
        display: block;
    }
    
    .banner-img {
        height: 400px;
    }
    
    .brand-tagline {
        font-size: 1.4rem;
    }
    
    .banner-content {
        padding: 1.5rem;
        margin: 0 1rem;
    }
    
    .gallery-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-inner {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .section {
        padding: 3rem 0;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
}

@media (max-width: 480px) {
    .video-grid {
        grid-template-columns: 1fr;
    }
    
    .ai-features {
        grid-template-columns: 1fr;
    }
    
    .creators-grid {
        grid-template-columns: 1fr;
    }
    
    .reviews-grid {
        grid-template-columns: 1fr;
    }
    
    .inner-pages-grid {
        grid-template-columns: 1fr 1fr;
    }
    
    .banner-btns {
        flex-direction: column;
        align-items: center;
    }
}