/* ========================================
   51吃瓜每日投稿 - 全站样式表
   品牌：51吃瓜每日投稿 | songjiujiang.com
   ======================================== */

/* --- Reset & Base --- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:"PingFang SC","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;color:#333;background:#f8f9fa;line-height:1.7;-webkit-font-smoothing:antialiased}
a{color:#ff6b6b;text-decoration:none;transition:color .3s}
a:hover{color:#e74c3c}
img{max-width:100%;height:auto;display:block}
ul,ol{list-style:none}
h1,h2,h3,h4,h5,h6{font-weight:700;line-height:1.3;color:#222}

/* --- Container --- */
.container{max-width:1200px;margin:0 auto;padding:0 20px}
.section{padding:60px 0}
.section-title{text-align:center;margin-bottom:40px}
.section-title h2{font-size:28px;color:#222;margin-bottom:10px;position:relative;display:inline-block}
.section-title h2::after{content:'';display:block;width:60px;height:3px;background:linear-gradient(90deg,#ff6b6b,#2ecc71);margin:10px auto 0}
.section-title p{color:#777;font-size:15px;max-width:600px;margin:0 auto}

/* --- Header --- */
.site-header{background:#fff;box-shadow:0 2px 10px rgba(0,0,0,.08);position:sticky;top:0;z-index:1000}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:12px 20px;max-width:1200px;margin:0 auto}
.logo{display:flex;align-items:center;gap:10px}
.logo img{height:45px;width:auto}
.logo span{font-size:20px;font-weight:700;color:#222;white-space:nowrap}
.main-nav{display:flex;align-items:center;gap:0}
.main-nav a{padding:10px 16px;color:#555;font-size:15px;font-weight:500;transition:all .3s;border-bottom:2px solid transparent}
.main-nav a:hover,.main-nav a.active{color:#ff6b6b;border-bottom-color:#ff6b6b}
.nav-toggle{display:none;background:none;border:none;font-size:24px;cursor:pointer;color:#333;padding:5px}

/* --- Search Bar --- */
.search-bar{background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);padding:15px 0}
.search-bar .container{display:flex;justify-content:center}
.search-form{display:flex;max-width:600px;width:100%;background:#fff;border-radius:25px;overflow:hidden;box-shadow:0 4px 15px rgba(0,0,0,.15)}
.search-form input{flex:1;border:none;padding:12px 20px;font-size:15px;outline:none;background:transparent}
.search-form button{background:#ff6b6b;color:#fff;border:none;padding:12px 25px;cursor:pointer;font-size:15px;transition:background .3s}
.search-form button:hover{background:#e74c3c}

/* --- Hero Banner --- */
.hero{position:relative;height:480px;overflow:hidden;background:#1a1a2e}
.hero img{width:100%;height:100%;object-fit:cover;opacity:.6}
.hero-content{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);text-align:center;color:#fff;width:90%;max-width:700px}
.hero h1{font-size:36px;margin-bottom:15px;text-shadow:2px 2px 8px rgba(0,0,0,.5)}
.hero p{font-size:18px;margin-bottom:25px;text-shadow:1px 1px 4px rgba(0,0,0,.5)}
.hero .btn{display:inline-block;padding:14px 35px;background:#ff6b6b;color:#fff;border-radius:30px;font-size:16px;font-weight:600;transition:all .3s;box-shadow:0 4px 15px rgba(255,107,107,.4)}
.hero .btn:hover{background:#e74c3c;transform:translateY(-2px);box-shadow:0 6px 20px rgba(255,107,107,.6)}

/* --- Video Cards --- */
.video-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.video-card{background:#fff;border-radius:12px;overflow:hidden;box-shadow:0 4px 15px rgba(0,0,0,.08);transition:all .3s;cursor:pointer}
.video-card:hover{transform:translateY(-5px);box-shadow:0 8px 25px rgba(0,0,0,.15)}
.video-thumb{position:relative;padding-top:56.25%;overflow:hidden}
.video-thumb img,.video-thumb video{position:absolute;top:0;left:0;width:100%;height:100%;object-fit:cover;transition:transform .5s}
.video-card:hover .video-thumb img,.video-card:hover .video-thumb video{transform:scale(1.05)}
.video-play{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%) scale(0);width:60px;height:60px;background:rgba(255,107,107,.9);border-radius:50%;display:flex;align-items:center;justify-content:center;transition:all .3s;opacity:0}
.video-play::after{content:'';display:block;width:0;height:0;border-style:solid;border-width:10px 0 10px 18px;border-color:transparent transparent transparent #fff;margin-left:4px}
.video-card:hover .video-play{transform:translate(-50%,-50%) scale(1);opacity:1}
.video-duration{position:absolute;bottom:8px;right:8px;background:rgba(0,0,0,.75);color:#fff;padding:2px 8px;border-radius:4px;font-size:12px}
.video-info{padding:12px 15px}
.video-info h3{font-size:14px;margin-bottom:6px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;line-height:1.4}
.video-meta{display:flex;align-items:center;gap:12px;color:#999;font-size:12px}
.video-meta span{display:flex;align-items:center;gap:3px}
.video-tag{display:inline-block;background:#fff0f0;color:#ff6b6b;padding:2px 8px;border-radius:10px;font-size:11px;margin-top:6px}

/* --- Feature Modules --- */
.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:25px}
.feature-card{background:#fff;border-radius:12px;padding:30px 25px;text-align:center;box-shadow:0 4px 15px rgba(0,0,0,.06);transition:all .3s}
.feature-card:hover{transform:translateY(-5px);box-shadow:0 8px 25px rgba(0,0,0,.12)}
.feature-icon{width:70px;height:70px;margin:0 auto 20px;background:linear-gradient(135deg,#ff6b6b,#ff8e8e);border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:30px;color:#fff}
.feature-card h3{font-size:18px;margin-bottom:10px;color:#222}
.feature-card p{color:#777;font-size:14px;line-height:1.6}

/* --- Expert Section --- */
.expert-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:25px}
.expert-card{background:#fff;border-radius:12px;overflow:hidden;box-shadow:0 4px 15px rgba(0,0,0,.06);text-align:center;padding:30px 20px;transition:all .3s}
.expert-card:hover{transform:translateY(-5px);box-shadow:0 8px 25px rgba(0,0,0,.12)}
.expert-avatar{width:100px;height:100px;border-radius:50%;margin:0 auto 15px;overflow:hidden;border:3px solid #ff6b6b}
.expert-avatar img{width:100%;height:100%;object-fit:cover}
.expert-card h3{font-size:17px;margin-bottom:5px}
.expert-card .title{color:#ff6b6b;font-size:13px;margin-bottom:10px}
.expert-card p{color:#777;font-size:13px;line-height:1.6;margin-bottom:15px}
.expert-btns{display:flex;gap:10px;justify-content:center}
.expert-btns a{padding:6px 16px;border-radius:20px;font-size:13px;transition:all .3s}
.expert-btns .btn-primary{background:#ff6b6b;color:#fff}
.expert-btns .btn-primary:hover{background:#e74c3c}
.expert-btns .btn-outline{border:1px solid #ff6b6b;color:#ff6b6b}
.expert-btns .btn-outline:hover{background:#ff6b6b;color:#fff}

/* --- Brand Wall --- */
.brand-wall{display:flex;flex-wrap:wrap;justify-content:center;gap:30px;align-items:center}
.brand-wall .brand-item{background:#fff;padding:15px 25px;border-radius:10px;box-shadow:0 2px 10px rgba(0,0,0,.06);font-size:16px;font-weight:600;color:#555;transition:all .3s}
.brand-wall .brand-item:hover{box-shadow:0 4px 15px rgba(0,0,0,.12);transform:translateY(-3px)}

/* --- FAQ --- */
.faq-list{max-width:800px;margin:0 auto}
.faq-item{background:#fff;border-radius:10px;margin-bottom:12px;box-shadow:0 2px 10px rgba(0,0,0,.05);overflow:hidden}
.faq-question{padding:18px 25px;cursor:pointer;display:flex;justify-content:space-between;align-items:center;font-weight:600;font-size:15px;color:#333;transition:background .3s}
.faq-question:hover{background:#f8f8f8}
.faq-question::after{content:'+';font-size:22px;color:#ff6b6b;transition:transform .3s;font-weight:300}
.faq-item.active .faq-question::after{transform:rotate(45deg)}
.faq-answer{padding:0 25px;max-height:0;overflow:hidden;transition:all .3s ease;color:#666;font-size:14px;line-height:1.7}
.faq-item.active .faq-answer{padding:0 25px 18px;max-height:300px}

/* --- Reviews --- */
.review-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:20px}
.review-card{background:#fff;border-radius:12px;padding:25px;box-shadow:0 4px 15px rgba(0,0,0,.06)}
.review-header{display:flex;align-items:center;gap:12px;margin-bottom:12px}
.review-avatar{width:45px;height:45px;border-radius:50%;background:linear-gradient(135deg,#ff6b6b,#ffa07a);display:flex;align-items:center;justify-content:center;color:#fff;font-weight:700;font-size:18px}
.review-name{font-weight:600;font-size:15px}
.review-date{color:#999;font-size:12px}
.review-stars{color:#ffc107;font-size:14px;margin-bottom:8px}
.review-text{color:#555;font-size:14px;line-height:1.7}

/* --- Contact --- */
.contact-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:30px}
.contact-info{background:#fff;border-radius:12px;padding:30px;box-shadow:0 4px 15px rgba(0,0,0,.06)}
.contact-info h3{font-size:20px;margin-bottom:20px;color:#222}
.contact-item{display:flex;align-items:flex-start;gap:12px;margin-bottom:15px;color:#555;font-size:14px}
.contact-item .icon{width:36px;height:36px;background:#fff0f0;border-radius:50%;display:flex;align-items:center;justify-content:center;color:#ff6b6b;font-size:16px;flex-shrink:0}
.qr-codes{display:flex;gap:20px;justify-content:center;flex-wrap:wrap}
.qr-item{text-align:center}
.qr-item img{width:150px;height:150px;border-radius:10px;margin-bottom:8px}
.qr-item p{font-size:13px;color:#666}

/* --- How-To Guide --- */
.howto-steps{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;max-width:900px;margin:0 auto}
.howto-step{text-align:center;position:relative}
.howto-step .step-num{width:50px;height:50px;background:linear-gradient(135deg,#ff6b6b,#ff8e8e);border-radius:50%;display:flex;align-items:center;justify-content:center;color:#fff;font-size:20px;font-weight:700;margin:0 auto 15px}
.howto-step h4{font-size:15px;margin-bottom:8px;color:#222}
.howto-step p{color:#777;font-size:13px}

/* --- Social Share --- */
.share-bar{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
.share-btn{display:inline-flex;align-items:center;gap:6px;padding:8px 18px;border-radius:20px;color:#fff;font-size:13px;transition:all .3s}
.share-btn:hover{transform:translateY(-2px);color:#fff}
.share-btn.wechat{background:#07c160}
.share-btn.weibo{background:#e6162d}
.share-btn.douyin{background:#161823}
.share-btn.bilibili{background:#00a1d6}

/* --- Footer --- */
.site-footer{background:#1a1a2e;color:#ccc;padding:50px 0 0}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:30px;margin-bottom:40px}
.footer-brand .logo-text{font-size:22px;font-weight:700;color:#fff;margin-bottom:12px}
.footer-brand p{font-size:13px;line-height:1.7;color:#aaa}
.footer-col h4{color:#fff;font-size:16px;margin-bottom:15px;position:relative;padding-bottom:10px}
.footer-col h4::after{content:'';position:absolute;bottom:0;left:0;width:30px;height:2px;background:#ff6b6b}
.footer-col a{display:block;color:#aaa;font-size:13px;padding:4px 0;transition:color .3s}
.footer-col a:hover{color:#ff6b6b}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding:20px 0;text-align:center;font-size:13px;color:#888}
.footer-bottom a{color:#aaa}

/* --- Breadcrumb --- */
.breadcrumb{padding:12px 0;font-size:13px;color:#999}
.breadcrumb a{color:#666}
.breadcrumb a:hover{color:#ff6b6b}
.breadcrumb span{margin:0 6px;color:#ccc}

/* --- Page Header --- */
.page-header{background:linear-gradient(135deg,#1a1a2e 0%,#16213e 100%);padding:50px 0;color:#fff;text-align:center}
.page-header h1{font-size:32px;margin-bottom:10px}
.page-header p{font-size:15px;color:#ccc;max-width:600px;margin:0 auto}

/* --- Lazy Load --- */
img[data-src]{opacity:0;transition:opacity .5s}
img.loaded{opacity:1}

/* --- Responsive --- */
@media(max-width:992px){
  .video-grid{grid-template-columns:repeat(3,1fr)}
  .feature-grid{grid-template-columns:repeat(2,1fr)}
  .expert-grid{grid-template-columns:repeat(2,1fr)}
  .footer-grid{grid-template-columns:repeat(2,1fr)}
  .howto-steps{grid-template-columns:repeat(2,1fr)}
  .hero h1{font-size:28px}
}
@media(max-width:768px){
  .header-inner{flex-wrap:wrap}
  .main-nav{display:none;width:100%;flex-direction:column;padding:10px 0}
  .main-nav.active{display:flex}
  .main-nav a{padding:10px 0;border-bottom:1px solid #f0f0f0}
  .nav-toggle{display:block}
  .video-grid{grid-template-columns:repeat(2,1fr)}
  .feature-grid{grid-template-columns:1fr}
  .expert-grid{grid-template-columns:1fr}
  .review-grid{grid-template-columns:1fr}
  .contact-grid{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .howto-steps{grid-template-columns:1fr}
  .hero{height:350px}
  .hero h1{font-size:24px}
  .hero p{font-size:15px}
  .section{padding:40px 0}
  .section-title h2{font-size:22px}
  .author-info{flex-wrap:wrap}
  .trust-badges{gap:8px}
  .trust-badge{font-size:12px;padding:6px 12px}
}
@media(max-width:480px){
  .video-grid{grid-template-columns:1fr}
  .search-form{flex-direction:column}
  .search-form button{border-radius:0}
}

/* --- Animations --- */
@keyframes fadeInUp{from{opacity:0;transform:translateY(30px)}to{opacity:1;transform:translateY(0)}}
.animate-in{animation:fadeInUp .6s ease forwards;opacity:0}

/* --- Author Info --- */
.author-info{display:flex;align-items:center;gap:10px;padding:10px 0;margin-bottom:15px;border-bottom:1px solid #f0f0f0;font-size:13px;color:#888}
.author-info img{width:30px;height:30px;border-radius:50%}
.author-info .author-name{font-weight:600;color:#333}
.publish-time{font-size:12px;color:#999;margin-top:5px}

/* --- Trust Badge --- */
.trust-badges{display:flex;flex-wrap:wrap;gap:15px;justify-content:center;padding:20px 0}
.trust-badge{display:flex;align-items:center;gap:6px;padding:8px 16px;background:#f8f9fa;border-radius:8px;font-size:13px;color:#555;border:1px solid #e8e8e8}
.trust-badge .badge-icon{font-size:18px}

/* --- Back to Top --- */
#backToTop{display:none;position:fixed;bottom:30px;right:30px;width:45px;height:45px;background:#ff6b6b;color:#fff;border:none;border-radius:50%;cursor:pointer;font-size:20px;align-items:center;justify-content:center;box-shadow:0 4px 15px rgba(255,107,107,.4);transition:all .3s;z-index:999}
#backToTop:hover{background:#e74c3c;transform:translateY(-3px)}

/* --- Utility --- */
.text-center{text-align:center}
.mt-20{margin-top:20px}
.mb-20{margin-bottom:20px}
.bg-light{background:#f8f9fa}
.bg-white{background:#fff}