/* 专题页布局 */
.topic-page-layout {
    display: flex;
    gap: 24px;
    padding: 0 22px 40px;
}
.topic-main-area {
    flex: 1;
    min-width: 0;
}

/* 中间栏容器隔离 — 使用站点design token */
.topic-middle-col {
    --tc-green: rgba(116, 255, 82, 1);
    --tc-blue: rgba(2, 137, 255, 1);
    --tc-gold: rgba(238, 184, 6, 1);
    --tc-bg: rgba(10, 10, 10, 1);
    --tc-card: rgba(255, 255, 255, 0.05);
    --tc-card-hover: rgba(255, 255, 255, 0.08);
    --tc-card-inner: rgba(255, 255, 255, 0.03);
    --tc-border: rgba(255, 255, 255, 0.1);
    --tc-border-light: rgba(255, 255, 255, 0.05);
    --tc-text: rgba(255, 255, 255, 1);
    --tc-text-80: rgba(255, 255, 255, 0.8);
    --tc-text-60: rgba(255, 255, 255, 0.6);
    --tc-text-40: rgba(255, 255, 255, 0.4);
    --tc-radius: 16px;
    --tc-radius-sm: 10px;
    --tc-radius-xs: 8px;
    width: 100%;
    background-color: var(--tc-bg);
    color: var(--tc-text);
    line-height: 1.6;
    box-sizing: border-box;
    font-family: 'PingFangSC-Medium', 'Microsoft Yahei', sans-serif;
}
.topic-middle-col * {
    box-sizing: border-box;
}
.topic-middle-col .container {
    width: 100%;
    padding: 15px;
}

/* ====== Banner ====== */
.topic-middle-col .banner {
    width: 100%;
    height: 320px;
    border-radius: var(--tc-radius);
    overflow: hidden;
    position: relative;
    margin-bottom: 30px;
    background: linear-gradient(135deg, #0a0a0a 0%, #1a1a2e 50%, #0a0a0a 100%);
}
.topic-middle-col .banner-bg-img {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    object-fit: cover;
    z-index: 0;
}
.topic-middle-col .banner-content {
    position: absolute;
    left: 0; right: 0; bottom: 0;
    z-index: 1;
    padding: 30px;
    background: linear-gradient(to top, rgba(0,0,0,0.75) 0%, rgba(0,0,0,0.35) 60%, transparent 100%);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}
.topic-middle-col .banner-title {
    font-size: 28px;
    font-weight: 600;
    color: #FFFFFF;
    margin: 0 0 8px 0;
    font-family: 'PingFangSC-Semibold', sans-serif;
}
.topic-middle-col .banner-subtitle {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.8);
    margin: 0 0 20px 0;
}
.topic-middle-col .banner-buttons {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
}
.topic-middle-col .banner-btn {
    padding: 10px 28px;
    border: none;
    border-radius: var(--tc-radius-sm);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    text-decoration: none;
    white-space: nowrap;
    font-family: 'PingFangSC-Medium', sans-serif;
}
.topic-middle-col .banner-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.3);
}
.topic-middle-col .btn-primary {
    background: linear-gradient(135deg, #0289FF 0%, #0066CC 100%);
    color: #fff;
}
.topic-middle-col .btn-success {
    background: linear-gradient(135deg, #74FF52 0%, #00D26A 100%);
    color: #000;
}

/* ====== Section title bar (统一标题风格) ====== */
.topic-middle-col .section-title {
    font-size: 18px;
    font-weight: 600;
    color: #FFFFFF;
    display: flex;
    align-items: center;
    font-family: 'PingFangSC-Semibold', sans-serif;
    margin: 0 0 20px 0;
}
.topic-middle-col .section-title::before {
    content: "";
    width: 4px;
    height: 18px;
    background: var(--tc-green);
    border-radius: 2px;
    margin-right: 10px;
    flex-shrink: 0;
}

/* ====== Core Intro Cards ====== */
.topic-middle-col .core-intro {
    display: flex;
    gap: 20px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}
.topic-middle-col .core-card {
    flex: 1;
    min-width: 280px;
    background: var(--tc-card);
    border: 1px solid var(--tc-border);
    border-radius: var(--tc-radius);
    padding: 20px;
}
.topic-middle-col .card-title {
    font-size: 16px;
    font-weight: 600;
    color: #FFFFFF;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    font-family: 'PingFangSC-Semibold', sans-serif;
}
.topic-middle-col .card-title::before {
    content: "";
    width: 4px;
    height: 16px;
    background: var(--tc-green);
    border-radius: 2px;
    margin-right: 10px;
    flex-shrink: 0;
}
.topic-middle-col .card-text-content {
    color: var(--tc-text-60);
    font-size: 13px;
    line-height: 1.7;
}
.topic-middle-col .card-list-content {
    list-style: none;
    padding: 0;
    margin: 0;
}
.topic-middle-col .card-list-content li {
    font-size: 13px;
    color: var(--tc-text-80);
    padding: 8px 0;
    padding-left: 20px;
    position: relative;
    border-bottom: 1px solid var(--tc-border-light);
}
.topic-middle-col .card-list-content li:last-child {
    border-bottom: none;
}
.topic-middle-col .card-list-content li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 6px;
    height: 6px;
    background: var(--tc-green);
    border-radius: 50%;
}

/* ====== Case Showcase ====== */
.topic-middle-col .case-showcase {
    background: var(--tc-card);
    border: 1px solid var(--tc-border);
    border-radius: var(--tc-radius);
    padding: 20px;
    margin-bottom: 30px;
}
.topic-middle-col .case-list {
    display: flex;
    gap: 14px;
    overflow-x: auto;
    padding-bottom: 8px;
    -webkit-overflow-scrolling: touch;
}
.topic-middle-col .case-list::-webkit-scrollbar {
    height: 4px;
    background: transparent;
}
.topic-middle-col .case-list::-webkit-scrollbar-thumb {
    background: rgba(116, 255, 82, 0.3);
    border-radius: 2px;
}
.topic-middle-col .case-list::-webkit-scrollbar-thumb:hover {
    background: rgba(116, 255, 82, 0.5);
}
.topic-middle-col .case-item {
    flex: 0 0 auto;
    width: 200px;
    height: 260px;
    border-radius: var(--tc-radius-sm);
    overflow: hidden;
    border: 1px solid var(--tc-border);
    transition: all 0.3s ease;
    background: var(--tc-card-inner);
}
.topic-middle-col .case-item:hover {
    border-color: var(--tc-green);
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(116, 255, 82, 0.1);
}
.topic-middle-col .case-item img {
    width: 100%; height: 100%;
    object-fit: cover;
    display: block;
}
.topic-middle-col .case-item a {
    display: block;
    width: 100%; height: 100%;
}

/* ====== Guide / Articles ====== */
.topic-middle-col .usage-guide {
    background: var(--tc-card);
    border: 1px solid var(--tc-border);
    border-radius: var(--tc-radius);
    padding: 20px;
}
.topic-middle-col .guide-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}
.topic-middle-col .guide-header .section-title {
    margin: 0;
}
.topic-middle-col .more-btn {
    font-size: 13px;
    color: var(--tc-green);
    text-decoration: none;
    flex-shrink: 0;
    transition: opacity 0.2s;
}
.topic-middle-col .more-btn:hover {
    opacity: 0.8;
}
.topic-middle-col .guide-list {
    display: flex;
    flex-direction: column;
    gap: 14px;
}
.topic-middle-col .guide-item {
    display: flex;
    gap: 14px;
    padding: 14px;
    background: var(--tc-card-inner);
    border-radius: var(--tc-radius-sm);
    transition: all 0.3s ease;
    text-decoration: none;
    color: inherit;
}
.topic-middle-col .guide-item:hover {
    background: var(--tc-card-hover);
    transform: translateX(3px);
}
.topic-middle-col .guide-thumbnail {
    width: 120px;
    height: 80px;
    object-fit: cover;
    border-radius: var(--tc-radius-xs);
    flex-shrink: 0;
    background-color: rgba(255, 255, 255, 0.03);
}
.topic-middle-col .guide-info {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
}
.topic-middle-col .guide-title {
    font-size: 15px;
    font-weight: 500;
    color: #FFFFFF;
    margin-bottom: 8px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.topic-middle-col .guide-meta {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 12px;
    color: var(--tc-text-40);
    flex-wrap: wrap;
}
.topic-middle-col .guide-tag {
    background: rgba(116, 255, 82, 0.15);
    color: var(--tc-green);
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 11px;
}

/* ====== Mobile ====== */
@media (max-width: 768px) {
    .topic-page-layout {
        padding: 0;
        gap: 0;
    }
    .topic-middle-col .container {
        padding: 12px;
    }
    /* banner */
    .topic-middle-col .banner {
        height: 200px;
        border-radius: 0;
        margin-bottom: 20px;
    }
    .topic-middle-col .banner-content {
        padding: 16px;
    }
    .topic-middle-col .banner-title {
        font-size: 20px;
    }
    .topic-middle-col .banner-subtitle {
        font-size: 12px;
        margin-bottom: 14px;
    }
    .topic-middle-col .banner-buttons {
        flex-direction: row;
        gap: 10px;
    }
    .topic-middle-col .banner-btn {
        padding: 8px 18px;
        font-size: 12px;
        border-radius: 8px;
    }
    /* cards */
    .topic-middle-col .core-intro {
        flex-direction: column;
        gap: 14px;
        margin-bottom: 20px;
    }
    .topic-middle-col .core-card {
        min-width: 100%;
        border-radius: 12px;
        padding: 16px;
    }
    /* cases */
    .topic-middle-col .case-showcase {
        border-radius: 12px;
        padding: 16px;
        margin-bottom: 20px;
    }
    .topic-middle-col .case-list {
        gap: 10px;
    }
    .topic-middle-col .case-item {
        width: 140px;
        height: 180px;
        border-radius: 8px;
    }
    /* guide */
    .topic-middle-col .usage-guide {
        border-radius: 12px;
        padding: 16px;
    }
    .topic-middle-col .guide-thumbnail {
        width: 90px;
        height: 65px;
    }
    .topic-middle-col .guide-title {
        font-size: 14px;
    }
    .topic-middle-col .guide-meta {
        flex-wrap: wrap;
        gap: 4px 8px;
        font-size: 11px;
    }
    .topic-middle-col .guide-tag {
        font-size: 10px;
        padding: 1px 6px;
    }
    .topic-middle-col .section-title {
        font-size: 16px;
    }
}
@media (max-width: 480px) {
    .topic-middle-col .banner {
        height: 170px;
    }
    .topic-middle-col .banner-title {
        font-size: 18px;
    }
    .topic-middle-col .banner-btn {
        padding: 7px 14px;
        font-size: 11px;
    }
    .topic-middle-col .case-item {
        width: 120px;
        height: 160px;
    }
}