/* ===== 全局变量 ===== */
:root {
    --primary: #4f6ef7;
    --primary-dark: #3a56d4;
    --primary-light: #e8ecff;
    --secondary: #ff6b6b;
    --success: #2ecc71;
    --warning: #f39c12;
    --danger: #e74c3c;
    --gray-50: #f8f9fa;
    --gray-100: #f1f3f5;
    --gray-200: #e9ecef;
    --gray-300: #dee2e6;
    --gray-400: #ced4da;
    --gray-500: #adb5bd;
    --gray-600: #6c757d;
    --gray-700: #495057;
    --gray-800: #343a40;
    --gray-900: #212529;
    --radius: 12px;
    --shadow: 0 2px 12px rgba(0,0,0,0.08);
    --shadow-hover: 0 4px 20px rgba(0,0,0,0.12);
    --transition: all 0.3s ease;
    --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
}
* { margin:0; padding:0; box-sizing:border-box; }
body { font-family:var(--font); background:var(--gray-50); color:var(--gray-800); line-height:1.6; padding-top:60px; }
a { text-decoration:none; color:var(--primary); }
a:hover { color:var(--primary-dark); }
img { max-width:100%; }

/* ===== 导航 ===== */
.navbar {
    position:fixed; top:0; left:0; right:0; z-index:1000;
    background:rgba(255,255,255,0.95); backdrop-filter:blur(10px);
    height:60px; display:flex; align-items:center; padding:0 20px;
    box-shadow:0 1px 4px rgba(0,0,0,0.06);
}
.navbar .logo { font-size:22px; font-weight:700; color:var(--primary); margin-right:30px; }
.navbar .logo span { color:var(--gray-800); }
.menu-toggle { display:none; background:none; border:none; font-size:24px; cursor:pointer; color:var(--gray-700); padding:4px 8px; }
.nav-links { display:flex; gap:6px; flex:1; flex-wrap:wrap; }
.nav-links a { padding:6px 14px; border-radius:8px; font-size:14px; color:var(--gray-700); font-weight:500; transition:var(--transition); }
.nav-links a:hover, .nav-links a.active { background:var(--primary-light); color:var(--primary); }
.nav-right { display:flex; align-items:center; gap:12px; margin-left:auto; }
.nav-right .user-score { font-size:13px; color:var(--gray-600); }
.nav-right .user-avatar {
    width:36px; height:36px; border-radius:50%; background:var(--primary-light);
    display:flex; align-items:center; justify-content:center; color:var(--primary);
    font-weight:600; font-size:14px; cursor:pointer; border:2px solid transparent;
    transition:var(--transition);
}
.nav-right .user-avatar:hover { border-color:var(--primary); }
.btn { padding:6px 18px; border-radius:8px; font-size:14px; font-weight:500; border:none; cursor:pointer; transition:var(--transition); }
.btn-primary { background:var(--primary); color:#fff; }
.btn-primary:hover { background:var(--primary-dark); }
.btn-outline { background:transparent; color:var(--gray-700); border:1px solid var(--gray-300); }
.btn-outline:hover { border-color:var(--primary); color:var(--primary); }

/* ===== 轮播图（1168x320 固定比例，自适应缩放） ===== */
.banner-slider {
    position: relative;
    border-radius: var(--radius);
    overflow: hidden;
    margin: 16px 0 24px;
    box-shadow: var(--shadow);
    background: #fff;
    /* 固定宽高比 1168:320，宽度自适应 */
    width: 100%;
    max-width: 1168px;   /* 容器最大宽度，超过则居中 */
    aspect-ratio: 1168 / 320;  /* 保持宽高比，高度由宽度自动计算 */
    margin-left: auto;
    margin-right: auto;
}

/* 如果浏览器不支持 aspect-ratio，使用 height: 0 + padding-top 降级方案（可选） */
@supports not (aspect-ratio: 1/1) {
    .banner-slider {
        height: 0;
        padding-top: calc(320 / 1168 * 100%);
        position: relative;
    }
    .banner-slider .slides {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
    }
}

.banner-slider .slides {
    display: flex;
    transition: transform 0.6s ease;
    width: 100%;
    height: 100%; /* 继承父容器高度 */
}

.banner-slider .slide {
    min-width: 100%;
    height: 100%;          /* 填满父容器 */
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    display: flex;
    align-items: center;
    padding: 40px;
    position: relative;
    color: #fff;
    flex-shrink: 0;
}

/* 如果使用 <img> 标签而不是背景图，则设置 object-fit */
.banner-slider .slide img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.banner-slider .slide .overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(0,0,0,0.5) 0%, transparent 70%);
    z-index: 1;
}

.banner-slider .slide .content {
    position: relative;
    z-index: 2;
    max-width: 60%;
}

.banner-slider .slide h2 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 8px;
    text-shadow: 0 2px 8px rgba(0,0,0,0.3);
}
.banner-slider .slide p {
    font-size: 18px;
    opacity: 0.9;
    text-shadow: 0 1px 4px rgba(0,0,0,0.3);
}
.banner-slider .slide .btn-slide {
    display: inline-block;
    margin-top: 12px;
    padding: 10px 24px;
    background: rgba(255,255,255,0.2);
    backdrop-filter: blur(4px);
    border-radius: 30px;
    color: #fff;
    font-weight: 600;
    transition: var(--transition);
}
.banner-slider .slide .btn-slide:hover {
    background: rgba(255,255,255,0.4);
}

/* 小点 */
.banner-slider .dots {
    position: absolute;
    bottom: 16px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 8px;
    z-index: 3;
}
.banner-slider .dots span {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: rgba(255,255,255,0.5);
    cursor: pointer;
    transition: var(--transition);
}
.banner-slider .dots span.active {
    background: #fff;
    transform: scale(1.2);
}

/* 箭头 */
.banner-slider .arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 3;
    background: rgba(255,255,255,0.2);
    backdrop-filter: blur(4px);
    border: none;
    color: #fff;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    font-size: 20px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}
.banner-slider .arrow:hover {
    background: rgba(255,255,255,0.4);
}
.banner-slider .arrow.prev { left: 12px; }
.banner-slider .arrow.next { right: 12px; }

/* ===== 响应式：平板及以下 ===== */
@media (max-width: 992px) {
    .banner-slider {
        max-width: 100%;
        aspect-ratio: 1168 / 320; /* 保持比例 */
        border-radius: 8px;
    }
    .banner-slider .slide {
        padding: 24px;
    }
    .banner-slider .slide h2 {
        font-size: 24px;
    }
    .banner-slider .slide p {
        font-size: 16px;
    }
}

@media (max-width: 768px) {
    .banner-slider .slide {
        padding: 16px;
    }
    .banner-slider .slide h2 {
        font-size: 20px;
    }
    .banner-slider .slide p {
        font-size: 14px;
    }
    .banner-slider .arrow {
        width: 32px;
        height: 32px;
        font-size: 16px;
    }
}

@media (max-width: 480px) {
    .banner-slider .slide {
        padding: 12px;
    }
    .banner-slider .slide h2 {
        font-size: 16px;
    }
    .banner-slider .slide p {
        font-size: 12px;
        display: none; /* 小屏隐藏描述 */
    }
    .banner-slider .arrow {
        display: none; /* 小屏隐藏箭头，用触摸滑动 */
    }
}
/* ===== 广告位 ===== */
.ad-row {
    display:grid; grid-template-columns:repeat(auto-fit, minmax(200px,1fr));
    gap:16px; margin:16px 0 24px;
}
.ad-item {
    background:#fff; border-radius:var(--radius); padding:16px 20px;
    box-shadow:var(--shadow); text-align:center; transition:var(--transition);
    cursor:pointer; border:1px solid transparent;
}
.ad-item:hover { box-shadow:var(--shadow-hover); border-color:var(--primary-light); transform:translateY(-2px); }
.ad-item .ad-icon { font-size:28px; margin-bottom:4px; }
.ad-item .ad-title { font-weight:600; font-size:15px; color:var(--gray-800); }
.ad-item .ad-desc { font-size:13px; color:var(--gray-500); }

/* ===== 布局 ===== */
.container { max-width:1200px; margin:0 auto; padding:0 16px; }
.forum-grid { display:grid; grid-template-columns:1fr 340px; gap:24px; margin-top:8px; }
.forum-main { min-width:0; }
.forum-sidebar { min-width:0; }

/* ===== 卡片 ===== */
.card {
    background:#fff; border-radius:var(--radius); box-shadow:var(--shadow);
    padding:20px 24px; margin-bottom:16px; transition:var(--transition);
    border:1px solid transparent;
}
.card:hover { box-shadow:var(--shadow-hover); }
.card-header {
    display:flex; justify-content:space-between; align-items:center;
    margin-bottom:16px; padding-bottom:12px; border-bottom:1px solid var(--gray-200);
}
.card-header h3 { font-size:18px; font-weight:600; }
.card-header .more { font-size:13px; color:var(--gray-500); }

/* ===== 帖子列表 ===== */
.post-item {
    display:flex; gap:14px; padding:14px 0; border-bottom:1px solid var(--gray-100);
    transition:var(--transition); cursor:pointer;
}
.post-item:last-child { border-bottom:none; }
.post-item:hover { padding-left:4px; }
.post-item .post-avatar {
    width:44px; height:44px; border-radius:50%; background:var(--primary-light);
    display:flex; align-items:center; justify-content:center;
    font-weight:600; font-size:16px; color:var(--primary); flex-shrink:0;
}
.post-item .post-body { flex:1; min-width:0; }
.post-item .post-title {
    font-weight:600; font-size:16px; color:var(--gray-800);
    display:-webkit-box; -webkit-line-clamp:2; -webkit-box-orient:vertical; overflow:hidden;
}
.post-item .post-title .vip-tag {
    display:inline-block; background:var(--secondary); color:#fff;
    font-size:11px; padding:0 8px; border-radius:4px; font-weight:600; margin-left:6px; vertical-align:middle;
}
.post-item .post-title .paid-tag {
    display:inline-block; background:var(--warning); color:#fff;
    font-size:11px; padding:0 8px; border-radius:4px; font-weight:600; margin-left:4px; vertical-align:middle;
}
.post-item .post-meta {
    font-size:13px; color:var(--gray-500); margin-top:4px;
    display:flex; gap:16px; flex-wrap:wrap;
}
.post-item .post-meta span { display:flex; align-items:center; gap:4px; }

/* ===== 侧边栏 ===== */
.sidebar-card {
    background:#fff; border-radius:var(--radius); box-shadow:var(--shadow);
    padding:18px 20px; margin-bottom:16px;
}
.sidebar-card h4 { font-size:15px; font-weight:600; margin-bottom:12px; color:var(--gray-800); }
.sidebar-card .user-rank-item {
    display:flex; align-items:center; gap:10px; padding:6px 0; font-size:14px;
}
.sidebar-card .user-rank-item .rank { font-weight:600; color:var(--gray-500); width:24px; }
.sidebar-card .user-rank-item .name { flex:1; color:var(--gray-700); }
.sidebar-card .user-rank-item .score { color:var(--warning); font-weight:500; }

.vip-card {
    background:linear-gradient(135deg,#f093fb 0%,#f5576c 100%);
    color:#fff; border-radius:var(--radius); padding:20px; margin-bottom:16px; text-align:center;
}
.vip-card h4 { font-size:18px; font-weight:700; margin-bottom:4px; }
.vip-card p { opacity:0.9; font-size:14px; margin-bottom:12px; }
.vip-card .btn {
    background:rgba(255,255,255,0.2); backdrop-filter:blur(4px);
    border:none; color:#fff; padding:8px 24px; border-radius:20px; font-weight:600; cursor:pointer;
    transition:var(--transition);
}
.vip-card .btn:hover { background:rgba(255,255,255,0.35); }

/* ===== 分页 ===== */
.pagination {
    display:flex; gap:6px; justify-content:center; margin-top:20px; flex-wrap:wrap;
}
.pagination a, .pagination span {
    padding:6px 14px; border-radius:6px; border:1px solid var(--gray-300);
    color:var(--gray-700); font-size:14px; transition:var(--transition); background:#fff;
}
.pagination a:hover { border-color:var(--primary); color:var(--primary); }
.pagination .active { background:var(--primary); color:#fff; border-color:var(--primary); }

/* ===== 发帖按钮 ===== */
.float-post-btn {
    position:fixed; bottom:24px; right:24px; z-index:999;
    background:var(--primary); color:#fff; width:56px; height:56px;
    border-radius:50%; display:flex; align-items:center; justify-content:center;
    font-size:28px; box-shadow:0 4px 16px rgba(79,110,247,0.4);
    cursor:pointer; transition:var(--transition); border:none;
}
.float-post-btn:hover { transform:scale(1.05); box-shadow:0 6px 24px rgba(79,110,247,0.5); }

/* ===== Toast ===== */
.toast {
    position:fixed; bottom:30px; left:50%; transform:translateX(-50%);
    background:var(--gray-900); color:#fff; padding:12px 24px; border-radius:10px;
    font-size:14px; z-index:9999; opacity:0; transition:opacity 0.4s ease;
    pointer-events:none; max-width:90%;
}
.toast.show { opacity:1; }
.toast.success { background:var(--success); }
.toast.error { background:var(--danger); }
.toast.warning { background:var(--warning); }

/* ===== 表单 ===== */
.form-group { margin-bottom:16px; }
.form-group label { display:block; font-weight:500; margin-bottom:4px; }
.form-group input, .form-group textarea, .form-group select {
    width:100%; padding:10px 14px; border:1px solid var(--gray-300);
    border-radius:8px; font-size:14px; transition:var(--transition); outline:none;
}
.form-group input:focus, .form-group textarea:focus, .form-group select:focus {
    border-color:var(--primary); box-shadow:0 0 0 3px rgba(79,110,247,0.1);
}
.btn-submit {
    width:100%; padding:12px; background:var(--primary); color:#fff;
    border:none; border-radius:8px; font-size:16px; font-weight:600; cursor:pointer;
    transition:var(--transition);
}
.btn-submit:hover { background:var(--primary-dark); }

/* ===== 响应式 ===== */
@media (max-width:992px) {
    .forum-grid { grid-template-columns:1fr; }
    .banner-slider .slide { height:240px; padding:24px; }
    .banner-slider .slide h2 { font-size:24px; }
    .banner-slider .slide .content { max-width:80%; }
}
@media (max-width:768px) {
    body { padding-top:56px; }
    .navbar { height:56px; padding:0 12px; }
    .navbar .logo { font-size:18px; margin-right:12px; }
    .navbar .logo span { display:none; }
    .nav-links {
        display:none; position:absolute; top:56px; left:0; right:0;
        background:#fff; flex-direction:column; padding:12px 16px;
        box-shadow:0 4px 12px rgba(0,0,0,0.08); border-top:1px solid var(--gray-200);
    }
    .nav-links.open { display:flex; }
    .nav-links a { padding:10px 14px; border-radius:8px; }
    .menu-toggle { display:block; }
    .nav-right .btn { padding:4px 12px; font-size:13px; }
    .banner-slider .slide { height:180px; padding:16px; }
    .banner-slider .slide h2 { font-size:18px; }
    .banner-slider .slide p { font-size:14px; }
    .banner-slider .arrow { width:32px; height:32px; font-size:16px; }
    .ad-row { grid-template-columns:repeat(2,1fr); gap:10px; }
    .ad-item { padding:12px 14px; }
    .ad-item .ad-icon { font-size:22px; }
    .card { padding:14px 16px; }
    .card-header h3 { font-size:16px; }
    .post-item .post-title { font-size:15px; }
    .post-item .post-meta { font-size:12px; gap:10px; }
    .post-item .post-avatar { width:36px; height:36px; font-size:13px; }
    .float-post-btn { width:48px; height:48px; font-size:22px; bottom:16px; right:16px; }
}
@media (max-width:480px) {
    .banner-slider .slide { height:140px; padding:12px; }
    .banner-slider .slide h2 { font-size:16px; }
    .banner-slider .slide p { font-size:12px; }
    .banner-slider .arrow { display:none; }
    .ad-row { grid-template-columns:1fr 1fr; gap:8px; }
    .container { padding:0 10px; }
    .card { padding:12px 14px; }
    .post-item { padding:10px 0; gap:10px; }
    .post-item .post-avatar { width:32px; height:32px; font-size:12px; }
    .post-item .post-title { font-size:14px; }
}