/* ============================================================
   课程页（/course/index 课程体系 · /course/view 课程详情）
   ------------------------------------------------------------
   风格：清爽学术风 —— 变量全部取自 theme.css，
        白底卡片 + 1px 细线 + 单一品牌青，无渐变、无投影、hover 只改颜色
   作用域：全部规则限定在 .crs-page 内，不影响全站
   说明：这一页原本是套 Yle 教育模板的独立静态 HTML（自带 head/body、
        大红主色、owl 轮播、animate.css 进场动画），现在改由站点布局包裹，
        视觉与首页/新闻/记录保持一致
   ============================================================ */

.crs-page {
    padding: 24px 0 8px;
}

/* ------------------------------------------------------- 级别切换条
   课程首页与课程详情页共用（views/course/_levelnav.php）：
   四个胶囊 —— 全部 / 01 入门 / 02 基础 / 03 提高，当前级别填品牌色。
   详情页靠它退回到某一类别的大纲，首页靠它在三个类别间横跳。 */
.crs-levelnav {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 0 0 22px;
}

.crs-levelnav-item {
    display: inline-flex;
    align-items: baseline;
    padding: 6px 15px;
    font-size: 12.5px;
    line-height: 1.5;
    color: var(--ink-3);
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 3px;
    transition: color .12s, border-color .12s, background-color .12s;
}

.crs-levelnav-item:hover,
.crs-levelnav-item:focus {
    color: var(--brand);
    border-color: var(--brand);
    text-decoration: none;
}

.crs-levelnav-item.is-on {
    color: #fff;
    background: var(--brand);
    border-color: var(--brand);
}

.crs-levelnav-item.is-on:hover {
    color: #fff;
}

.crs-levelnav-no {
    margin-right: 6px;
    font-variant-numeric: tabular-nums;
    opacity: .6;
}

.crs-levelnav-item.is-on .crs-levelnav-no {
    opacity: .78;
}

/* ---------------------------------------------------------------- 页头 */
.crs-head {
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    gap: 40px;
    padding-bottom: 18px;
    margin-bottom: 28px;
    border-bottom: 1px solid var(--line);
}

.crs-title {
    margin: 0;
    font-size: 22px;
    font-weight: 600;
    line-height: 1.3;
    letter-spacing: 0.2px;
}

.crs-sub {
    max-width: 640px;
    margin: 9px 0 0;
    font-size: 13px;
    line-height: 1.9;
    color: var(--ink-3);
}

.crs-filter-note {
    margin: 10px 0 0;
    font-size: 12.5px;
    color: var(--muted);
}

.crs-filter-note b {
    font-weight: 600;
    color: var(--brand);
}

.crs-filter-link {
    color: var(--brand);
    border-bottom: 1px solid transparent;
}

.crs-filter-link:hover {
    border-bottom-color: var(--brand);
}

/* 右侧统计：三个数字，去掉一切装饰 */
.crs-stat {
    display: flex;
    flex: 0 0 auto;
    gap: 30px;
    padding-bottom: 2px;
}

.crs-stat-item {
    text-align: right;
}

.crs-stat-num {
    display: block;
    font-size: 21px;
    font-weight: 600;
    line-height: 1.2;
    color: var(--ink);
    font-variant-numeric: tabular-nums;
}

.crs-stat-lab {
    display: block;
    margin-top: 2px;
    font-size: 11.5px;
    color: var(--muted);
}

/* ---------------------------------------------------------------- 级别分组 */
.crs-level {
    margin-bottom: 34px;
}

.crs-level-head {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    padding-bottom: 14px;
}

.crs-level-no {
    flex: 0 0 auto;
    margin-top: 1px;
    padding: 2px 8px;
    font-size: 11.5px;
    font-weight: 600;
    line-height: 17px;
    color: var(--brand);
    background: var(--brand-soft);
    border-radius: 2px;
    font-variant-numeric: tabular-nums;
    letter-spacing: 0.5px;
}

.crs-level-text {
    min-width: 0;
}

.crs-level-name {
    display: flex;
    align-items: baseline;
    gap: 8px;
    margin: 0;
    font-size: 15px;
    font-weight: 600;
}

.crs-level-en {
    font-size: 10.5px;
    font-weight: 400;
    color: var(--muted);
    letter-spacing: 0.8px;
    text-transform: uppercase;
}

.crs-level-desc {
    margin: 5px 0 0;
    font-size: 12.5px;
    line-height: 1.8;
    color: var(--ink-3);
}

.crs-level-for {
    flex: 0 0 auto;
    max-width: 250px;
    margin-left: auto;
    padding-top: 3px;
    font-size: 11.5px;
    line-height: 1.7;
    color: var(--muted);
    text-align: right;
}

/* ---------------------------------------------------------------- 课程卡片 */
.crs-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
}

.crs-card {
    display: flex;
    flex-direction: column;
    padding: 16px 18px 14px;
    background: var(--paper);
    border: 1px solid var(--line);
    border-radius: 3px;
    color: inherit;
    transition: border-color 0.15s ease, background-color 0.15s ease;
}

.crs-card:hover,
.crs-card:focus {
    border-color: var(--brand);
    color: inherit;
    text-decoration: none;
}

.crs-card-no {
    font-size: 11px;
    font-weight: 600;
    color: #A7B3AE;
    letter-spacing: 1px;
    font-variant-numeric: tabular-nums;
}

.crs-card-title {
    margin: 4px 0 0;
    font-size: 14.5px;
    font-weight: 600;
    line-height: 1.45;
    color: var(--ink);
    transition: color 0.15s ease;
}

.crs-card:hover .crs-card-title {
    color: var(--brand);
}

.crs-card-sub {
    margin: 5px 0 0;
    font-size: 12.5px;
    line-height: 1.75;
    color: var(--ink-3);
}

.crs-card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 11px;
    margin-bottom: 13px;
}

.crs-tag {
    padding: 0 7px;
    font-size: 11px;
    line-height: 19px;
    color: var(--ink-3);
    background: #F3F5F3;
    border-radius: 2px;
    white-space: nowrap;
}

.crs-card-foot {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    margin-top: auto;
    padding-top: 11px;
    border-top: 1px solid var(--line-soft);
}

.crs-card-meta {
    font-size: 11.5px;
    color: var(--muted);
    font-variant-numeric: tabular-nums;
}

.crs-card-meta .sep {
    margin: 0 5px;
    color: #D5DCD8;
}

.crs-card-go {
    flex: 0 0 auto;
    font-size: 11.5px;
    color: #B4BEBA;
    transition: color 0.15s ease;
}

.crs-card:hover .crs-card-go {
    color: var(--brand);
}

/* ---------------------------------------------------------------- 使用说明 */
.crs-howto {
    margin-top: 4px;
    padding: 22px 24px 20px;
    background: var(--paper);
    border: 1px solid var(--line);
    border-radius: 3px;
}

.crs-howto-title {
    margin: 0 0 15px;
    font-size: 13px;
    font-weight: 600;
}

.crs-howto-list {
    margin: 0;
    padding: 0;
    list-style: none;
    counter-reset: howto;
}

.crs-howto-list li {
    position: relative;
    padding-left: 32px;
    margin-bottom: 11px;
    font-size: 12.5px;
    line-height: 1.9;
    color: var(--ink-2);
}

.crs-howto-list li:last-child {
    margin-bottom: 0;
}

.crs-howto-list li::before {
    counter-increment: howto;
    content: counter(howto, decimal-leading-zero);
    position: absolute;
    left: 0;
    top: 1px;
    font-size: 11px;
    font-weight: 600;
    color: var(--brand);
    letter-spacing: 0.5px;
    font-variant-numeric: tabular-nums;
}

.crs-howto-list b {
    font-weight: 600;
    color: var(--ink);
}

.crs-howto-act {
    margin-top: 18px;
    padding-top: 16px;
    border-top: 1px solid var(--line-soft);
}

/* ---------------------------------------------------------------- 按钮 */
.crs-btn {
    display: inline-flex;
    align-items: center;
    height: 32px;
    padding: 0 16px;
    font-size: 12.5px;
    line-height: 32px;
    color: #fff;
    background: var(--brand);
    border-radius: 3px;
    white-space: nowrap;
    transition: background-color 0.15s ease;
}

.crs-btn:hover,
.crs-btn:focus {
    color: #fff;
    background: var(--brand-dark);
    text-decoration: none;
}

/* ================================================================
   课程详情
   ================================================================ */
.crs-dhead {
    padding-bottom: 20px;
    margin-bottom: 26px;
    border-bottom: 1px solid var(--line);
}

.crs-dhead-level {
    display: inline-block;
    padding: 2px 9px;
    font-size: 11.5px;
    line-height: 19px;
    color: var(--brand);
    background: var(--brand-soft);
    border-radius: 2px;
    letter-spacing: 0.3px;
}

.crs-dhead-level:hover {
    color: var(--brand-dark);
}

.crs-dhead-title {
    margin: 12px 0 0;
    font-size: 24px;
    font-weight: 600;
    line-height: 1.35;
    letter-spacing: 0.2px;
}

.crs-dhead-sub {
    margin: 7px 0 0;
    font-size: 13.5px;
    color: var(--ink-3);
}

.crs-dhead-desc {
    max-width: 780px;
    margin: 14px 0 0;
    font-size: 13px;
    line-height: 1.95;
    color: var(--ink-2);
}

.crs-dhead-meta {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    margin-top: 15px;
    font-size: 12px;
    color: var(--muted);
    font-variant-numeric: tabular-nums;
}

.crs-dhead-meta .sep {
    margin: 0 8px;
    color: #D5DCD8;
}

/* 两栏：正文 + 侧栏 */
.crs-body {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 28px;
    align-items: start;
}

.crs-main {
    min-width: 0;
}

.crs-sec-title {
    display: flex;
    align-items: baseline;
    gap: 10px;
    margin: 0 0 4px;
    font-size: 13px;
    font-weight: 600;
}

.crs-sec-note {
    font-size: 11.5px;
    font-weight: 400;
    color: var(--muted);
}

/* 章节列表：去掉卡片，用细线分隔，读起来像目录 */
.crs-chapters {
    margin: 0;
    padding: 0;
    list-style: none;
    border-top: 1px solid var(--line);
    margin-top: 12px;
}

.crs-ch {
    display: flex;
    gap: 14px;
    padding: 15px 0 16px;
    border-bottom: 1px solid var(--line-soft);
}

.crs-ch-no {
    flex: 0 0 auto;
    width: 24px;
    padding-top: 2px;
    font-size: 11.5px;
    font-weight: 600;
    color: #A7B3AE;
    font-variant-numeric: tabular-nums;
    letter-spacing: 0.5px;
}

.crs-ch-body {
    min-width: 0;
}

.crs-ch-title {
    display: flex;
    align-items: baseline;
    gap: 10px;
    margin: 0;
    font-size: 13.5px;
    font-weight: 600;
    line-height: 1.6;
}

.crs-ch-hour {
    flex: 0 0 auto;
    font-size: 11px;
    font-weight: 400;
    color: var(--muted);
}

.crs-ch-points {
    margin: 7px 0 0;
    padding: 0;
    list-style: none;
}

.crs-ch-points li {
    position: relative;
    padding-left: 13px;
    font-size: 12.5px;
    line-height: 1.9;
    color: var(--ink-3);
}

.crs-ch-points li::before {
    content: "";
    position: absolute;
    left: 2px;
    top: 10px;
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: #C9D2CE;
}

/* 练习引导条 */
.crs-practice {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    margin-top: 22px;
    padding: 15px 18px;
    background: var(--brand-soft);
    border-radius: 3px;
}

.crs-practice-text {
    font-size: 12.5px;
    line-height: 1.8;
    color: var(--ink-2);
}

.crs-practice-text b {
    font-weight: 600;
    color: var(--ink);
}

/* 侧栏 */
.crs-side {
    position: sticky;
    top: 72px;
}

.crs-side-card {
    padding: 15px 18px 16px;
    margin-bottom: 14px;
    background: var(--paper);
    border: 1px solid var(--line);
    border-radius: 3px;
}

.crs-side-title {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 8px;
    margin: 0 0 12px;
    font-size: 12.5px;
    font-weight: 600;
}

.crs-side-note {
    font-size: 11px;
    font-weight: 400;
    color: var(--muted);
}

.crs-goal {
    margin: 0;
    padding: 0;
    list-style: none;
}

.crs-goal li {
    position: relative;
    padding: 0 0 10px 18px;
    font-size: 12.5px;
    line-height: 1.85;
    color: var(--ink-2);
}

.crs-goal li:last-child {
    padding-bottom: 0;
}

.crs-goal li::before {
    content: "✓";
    position: absolute;
    left: 0;
    top: 0;
    font-size: 11px;
    color: var(--brand);
}

.crs-side-list {
    margin: 0;
    padding: 0;
    list-style: none;
}

.crs-side-list li {
    border-top: 1px solid var(--line-soft);
}

.crs-side-list li:first-child {
    border-top: 0;
}

.crs-side-list a {
    display: block;
    padding: 8px 0;
    font-size: 12.5px;
    color: var(--ink-2);
}

.crs-side-list a:hover {
    color: var(--brand);
}

.crs-side-no {
    margin-right: 7px;
    font-size: 11px;
    color: var(--muted);
    font-variant-numeric: tabular-nums;
}

/* 上一门 / 下一门 */
.crs-adj {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
    margin-top: 30px;
    padding-top: 22px;
    border-top: 1px solid var(--line);
}

.crs-adj-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
    padding: 13px 16px;
    background: var(--paper);
    border: 1px solid var(--line);
    border-radius: 3px;
    transition: border-color 0.15s ease;
}

.crs-adj-item.is-next {
    text-align: right;
}

.crs-adj-item.is-empty {
    background: transparent;
    border-color: transparent;
}

.crs-adj-item.is-empty .crs-adj-lab {
    color: #C0C9C5;
}

a.crs-adj-item:hover {
    border-color: var(--brand);
}

.crs-adj-lab {
    font-size: 11px;
    color: var(--muted);
}

.crs-adj-title {
    font-size: 13px;
    color: var(--ink);
    transition: color 0.15s ease;
}

a.crs-adj-item:hover .crs-adj-title {
    color: var(--brand);
}

/* ================================================================
   响应式
   ================================================================ */
@media (max-width: 1199px) {
    .crs-grid {
        gap: 12px;
    }

    .crs-level-for {
        max-width: 200px;
    }
}

@media (max-width: 991px) {
    /* 级别切换条在窄屏收一点，四项尽量一行放下 */
    .crs-levelnav {
        gap: 6px;
        margin-bottom: 18px;
    }

    .crs-levelnav-item {
        padding: 5px 12px;
        font-size: 12px;
    }

    .crs-head {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
    }

    .crs-stat {
        width: 100%;
        justify-content: space-between;
        gap: 0;
    }

    .crs-stat-item {
        text-align: left;
    }

    .crs-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .crs-level-for {
        display: none;
    }

    .crs-body {
        grid-template-columns: minmax(0, 1fr);
    }

    .crs-side {
        position: static;
    }
}

@media (max-width: 767px) {
    .crs-page {
        padding-top: 16px;
    }

    .crs-title {
        font-size: 19px;
    }

    .crs-sub {
        font-size: 12.5px;
    }

    .crs-stat-num {
        font-size: 18px;
    }

    .crs-grid {
        grid-template-columns: minmax(0, 1fr);
    }

    .crs-card {
        padding: 14px 15px 13px;
    }

    .crs-level {
        margin-bottom: 26px;
    }

    .crs-level-head {
        gap: 10px;
    }

    .crs-howto {
        padding: 18px 16px;
    }

    .crs-howto-list li {
        padding-left: 26px;
    }

    .crs-dhead-title {
        font-size: 20px;
    }

    .crs-dhead-desc {
        font-size: 12.5px;
    }

    .crs-practice {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .crs-ch {
        gap: 10px;
    }

    .crs-adj {
        grid-template-columns: minmax(0, 1fr);
    }

    .crs-adj-item.is-next {
        text-align: left;
    }
}