/* ===== 变量 ===== */
:root {
    --paper: #F5FBF9;
    --paper2: #EDF5F2;
    --paper3: #E0EDE8;
    --ink: #1A1A1A;
    --ink2: #3A3A3A;
    --ink3: #8A8A8A;
    --gold: #62C9B8;
    --gold2: #7DD4C6;
    --gold-bg: rgba(98, 201, 184, 0.10);
    --gold-bd: rgba(98, 201, 184, 0.28);
    --rule: rgba(98, 201, 184, 0.15);
    --card-bg: #FFFFFF;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.04);
    --shadow2: 0 8px 32px rgba(0, 0, 0, 0.08);
    --radius: 16px;
    --max-w: 480px;
    --font-serif: 'Noto Serif SC', serif;
    --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue", STHeiti, "Microsoft YaHei", Tahoma, Arial, sans-serif;
    --font-el: 'Cormorant Garamond', serif;
}

*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: linear-gradient(180deg, #F5FBF9 0%, #EAF5F1 100%);
    color: var(--ink);
    -webkit-font-smoothing: antialiased;
    padding: 20px 16px 60px;
    min-height: 100vh;
}

::-webkit-scrollbar {
    width: 6px;
}
::-webkit-scrollbar-track {
    background: var(--paper2);
}
::-webkit-scrollbar-thumb {
    background: var(--gold-bd);
    border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--gold);
}

.app-container {
    max-width: 1200px;
    margin: 0 auto;
}

/* ===== 头部 ===== */
.header {
    background: var(--paper);
    border-radius: 24px 24px 16px 16px;
    padding: 28px 32px 20px;
    box-shadow: 0 10px 40px -10px rgba(0, 0, 0, 0.06);
    margin-bottom: 20px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--rule);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 14px;
    flex-wrap: wrap;
}

.header-left .logo {
    font-size: 38px;
    line-height: 1;
}

.header-left h1 {
    font-family: var(--font-serif);
    font-size: 26px;
    font-weight: 900;
    color: var(--ink);
    letter-spacing: -.01em;
}
.header-left h1 em {
    font-style: normal;
    color: var(--gold2);
    position: relative;
}
.header-left h1 em::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 0;
    width: 100%;
    height: 6px;
    background-color: rgba(98, 201, 184, 0.18);
    z-index: -1;
}

.header-left .sub {
    font-size: 13px;
    color: var(--ink3);
    background: var(--paper2);
    padding: 4px 16px;
    border-radius: 30px;
    font-weight: 500;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
}

.stats-badge {
    background: var(--paper2);
    padding: 6px 18px;
    border-radius: 40px;
    font-size: 13px;
    font-weight: 600;
    color: var(--ink2);
    display: flex;
    align-items: center;
    gap: 10px;
}

/* ===== 筛选切换条 ===== */
.filter-toggle-bar {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 14px;
    margin-bottom: 14px;
    flex-wrap: wrap;
}

.filter-toggle-btn {
    padding: 8px 22px;
    border-radius: 40px;
    border: 1px solid var(--rule);
    background: var(--paper);
    font-size: 14px;
    font-weight: 600;
    color: var(--ink2);
    cursor: pointer;
    transition: all 0.25s;
    font-family: var(--font-sans);
    display: flex;
    align-items: center;
    gap: 6px;
    box-shadow: var(--shadow);
}
.filter-toggle-btn:hover {
    border-color: var(--gold-bd);
    background: var(--paper);
    transform: translateY(-1px);
    box-shadow: var(--shadow2);
}
.filter-toggle-btn.active {
    border-color: var(--gold);
    background: var(--gold);
    color: #fff;
    box-shadow: 0 4px 16px rgba(98, 201, 184, 0.28);
}
.filter-toggle-btn.active:hover {
    background: var(--gold2);
    border-color: var(--gold2);
}
.filter-toggle-btn .arrow {
    display: inline-block;
    transition: transform 0.3s ease;
    font-size: 14px;
}
.filter-toggle-btn.active .arrow {
    transform: rotate(180deg);
}

.filter-status {
    font-size: 13px;
    color: var(--ink3);
    font-weight: 500;
}

/* ===== 筛选栏 ===== */
.filter-section {
    background: var(--paper);
    border-radius: 16px;
    padding: 18px 24px;
    box-shadow: var(--shadow);
    margin-bottom: 20px;
    border: 1px solid var(--rule);
    overflow: hidden;
    transition: max-height 0.5s cubic-bezier(0.4, 0, 0.2, 1),
        opacity 0.4s ease,
        padding 0.4s ease,
        margin 0.4s ease;
    max-height: 800px;
    opacity: 1;
    padding: 18px 24px;
}
.filter-section.hidden {
    max-height: 0;
    opacity: 0;
    padding: 0 24px;
    margin-bottom: 0;
    border-width: 0;
    pointer-events: none;
}

.filter-row {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px 16px;
}

.filter-group {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 6px;
}

.filter-group .label {
    font-size: 13px;
    font-weight: 600;
    color: var(--ink3);
    margin-right: 2px;
}

.filter-btn {
    padding: 6px 16px;
    border-radius: 30px;
    border: 1px solid var(--rule);
    background: transparent;
    font-size: 13px;
    font-weight: 600;
    color: var(--ink2);
    cursor: pointer;
    transition: all 0.2s;
    font-family: var(--font-sans);
}
.filter-btn:hover {
    border-color: var(--gold-bd);
    background: var(--gold-bg);
}
.filter-btn.active {
    border-color: var(--gold);
    background: var(--gold);
    color: #fff;
    box-shadow: 0 2px 12px rgba(98, 201, 184, 0.28);
}

.filter-btn.age-btn {
    min-width: 64px;
    justify-content: center;
}

.filter-btn.career-btn {
    min-width: 48px;
    justify-content: center;
}
.filter-btn.career-btn .emoji {
    margin-right: 3px;
}

.filter-btn.knowledge-btn {
    min-width: 40px;
    justify-content: center;
}

.filter-clear {
    padding: 6px 14px;
    border-radius: 30px;
    border: none;
    background: var(--paper2);
    font-size: 12px;
    font-weight: 600;
    color: var(--ink3);
    cursor: pointer;
    transition: all 0.2s;
    font-family: var(--font-sans);
}
.filter-clear:hover {
    background: var(--paper3);
    color: var(--ink2);
}

/* ===== 工具栏 ===== */
.toolbar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
    gap: 12px;
}

.toolbar-left {
    display: flex;
    align-items: center;
    gap: 12px;
}

.toolbar-left .count {
    font-size: 14px;
    color: var(--ink3);
    font-weight: 500;
}
.toolbar-left .count strong {
    color: var(--ink);
    font-size: 17px;
    font-weight: 700;
}

.view-toggle {
    display: flex;
    background: var(--paper2);
    border-radius: 40px;
    padding: 3px;
    gap: 3px;
}
.view-toggle button {
    border: none;
    background: transparent;
    padding: 6px 18px;
    border-radius: 30px;
    font-size: 13px;
    font-weight: 600;
    color: var(--ink3);
    cursor: pointer;
    transition: all 0.2s;
    font-family: var(--font-sans);
}
.view-toggle button.active {
    background: var(--paper);
    color: var(--ink);
    box-shadow: var(--shadow);
}
.view-toggle button:hover:not(.active) {
    color: var(--ink);
}

/* ===== 课程网格 ===== */
.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 18px;
    transition: all 0.3s;
}

.course-grid.list-view {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

/* ===== 课程卡片 ===== */
.course-card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 20px 22px 18px;
    border: 1px solid var(--rule);
    box-shadow: var(--shadow);
    transition: all 0.3s;
    display: flex;
    flex-direction: column;
    position: relative;
    overflow: hidden;
}
.course-card:hover {
    border-color: var(--gold-bd);
    box-shadow: var(--shadow2);
    transform: translateY(-2px);
}

.course-card .top-row {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 10px;
    margin-bottom: 10px;
}

.course-card .top-row .left-tags {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 6px;
}

.course-card .course-id {
    font-family: var(--font-el);
    font-size: 14px;
    font-weight: 700;
    padding: 2px 12px;
    border-radius: 30px;
    background: var(--paper2);
    color: var(--ink3);
    white-space: nowrap;
    letter-spacing: 0.02em;
}

.course-card .age-tag {
    font-size: 11px;
    font-weight: 700;
    padding: 3px 12px;
    border-radius: 30px;
    background: var(--paper2);
    color: var(--ink2);
    white-space: nowrap;
}
.course-card .age-tag.age-5-8 {
    background: #fdebd0;
    color: #a04000;
}
.course-card .age-tag.age-9-12 {
    background: #d5f5e3;
    color: #1a6e3a;
}
.course-card .age-tag.age-13 {
    background: #d6eaf8;
    color: #1a5276;
}

.course-card .career-tag {
    font-size: 12px;
    font-weight: 700;
    padding: 3px 12px;
    border-radius: 30px;
    white-space: nowrap;
}
.career-tag.career-R {
    background: #fadbd8;
    color: #922b21;
}
.career-tag.career-I {
    background: #d4e6f1;
    color: #1a5276;
}
.career-tag.career-A {
    background: #ebdef0;
    color: #6c3483;
}
.career-tag.career-S {
    background: #d5f5e3;
    color: #1a6e3a;
}
.career-tag.career-E {
    background: #fdebd0;
    color: #a04000;
}
.career-tag.career-C {
    background: #e8e8e8;
    color: #5d6d7e;
}

.course-card .course-icon {
    font-size: 32px;
    line-height: 1;
    margin-bottom: 4px;
}

.course-card .course-title {
    font-family: var(--font-serif);
    font-size: 19px;
    font-weight: 700;
    color: var(--ink);
    margin: 4px 0 4px;
    line-height: 1.3;
    cursor: pointer;
    transition: color 0.2s;
    border-bottom: 2px solid transparent;
    display: inline-block;
    width: fit-content;
}
.course-card .course-title:hover {
    color: var(--gold2);
    border-bottom-color: var(--gold-bd);
}

.course-card .course-desc {
    font-size: 14px;
    color: var(--ink2);
    line-height: 1.65;
    margin-bottom: 10px;
    flex: 1;
    font-weight: 400;
}

.course-card .knowledge-wrap {
    display: flex;
    flex-wrap: wrap;
    gap: 5px;
    margin-bottom: 4px;
}
.course-card .knowledge-tag {
    font-size: 11px;
    font-weight: 500;
    padding: 2px 12px;
    border-radius: 20px;
    background: var(--paper2);
    color: var(--ink2);
    border: 1px solid var(--rule);
}

/* ===== 列表视图 ===== */
.course-grid.list-view .course-card {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    padding: 14px 20px;
    gap: 10px 16px;
}
.course-grid.list-view .course-card .top-row {
    margin-bottom: 0;
    flex: 0 0 auto;
    gap: 6px;
}
.course-grid.list-view .course-card .course-icon {
    font-size: 26px;
    margin-bottom: 0;
}
.course-grid.list-view .course-card .course-title {
    font-size: 16px;
    margin: 0;
    flex: 1 1 140px;
}
.course-grid.list-view .course-card .course-desc {
    margin-bottom: 0;
    flex: 2 1 200px;
    font-size: 13px;
}
.course-grid.list-view .course-card .knowledge-wrap {
    margin-bottom: 0;
    flex: 1 1 120px;
}
.course-grid.list-view .course-card .top-row .left-tags {
    flex-wrap: nowrap;
}

/* ===== 空状态 ===== */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    background: var(--paper);
    border-radius: 16px;
    box-shadow: var(--shadow);
    border: 1px solid var(--rule);
}
.empty-state .emoji {
    font-size: 48px;
    display: block;
    margin-bottom: 12px;
}
.empty-state h3 {
    font-family: var(--font-serif);
    font-size: 20px;
    color: var(--ink);
    margin-bottom: 6px;
}
.empty-state p {
    color: var(--ink3);
    font-size: 14px;
}

/* ===== 弹窗 ===== */
.popup-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.45);
    backdrop-filter: blur(6px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}
.popup-overlay.active {
    opacity: 1;
    visibility: visible;
}

.popup-card {
    background: var(--paper);
    border-radius: 24px;
    max-width: 640px;
    width: 94%;
    padding: 28px 32px 24px;
    box-shadow: 0 40px 80px rgba(0, 0, 0, 0.25);
    transform: scale(0.95) translateY(20px);
    transition: transform 0.35s ease, opacity 0.35s ease;
    opacity: 0;
    max-height: 88vh;
    overflow-y: auto;
    position: relative;
    border: 1px solid var(--rule);
}
.popup-overlay.active .popup-card {
    transform: scale(1) translateY(0);
    opacity: 1;
}

.popup-card .popup-close {
    position: sticky;
    top: 0;
    float: right;
    background: var(--paper);
    border: none;
    font-size: 28px;
    color: var(--ink3);
    cursor: pointer;
    transition: color 0.2s;
    line-height: 1;
    padding: 0 4px;
    z-index: 2;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: -8px;
    margin-right: -8px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.04);
}
.popup-card .popup-close:hover {
    color: var(--ink);
    background: var(--paper2);
}

.popup-card .popup-icon {
    font-size: 40px;
    margin-bottom: 4px;
}
.popup-card .popup-title {
    font-family: var(--font-serif);
    font-size: 24px;
    font-weight: 700;
    color: var(--ink);
    margin-bottom: 2px;
}
.popup-card .popup-sub {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 14px;
    font-size: 13px;
    font-weight: 600;
    color: var(--ink3);
}
.popup-card .popup-sub span {
    background: var(--paper2);
    padding: 2px 14px;
    border-radius: 30px;
}

/* 关联说明 */
.popup-card .popup-relation {
    font-size: 15px;
    line-height: 1.7;
    color: var(--ink2);
    background: var(--paper2);
    padding: 14px 18px;
    border-radius: 14px;
    border-left: 4px solid var(--gold);
    margin-bottom: 18px;
}
.popup-card .popup-relation strong {
    color: var(--ink);
}

/* 小课列表 */
.popup-card .popup-lessons-title {
    font-family: var(--font-serif);
    font-size: 18px;
    font-weight: 700;
    color: var(--ink);
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 10px;
}
.popup-card .popup-lessons-title .badge {
    font-size: 12px;
    font-weight: 600;
    background: var(--gold-bg);
    color: var(--gold2);
    padding: 0 14px;
    border-radius: 30px;
    border: 1px solid var(--gold-bd);
}

.popup-card .lesson-item {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 12px 16px;
    margin-bottom: 10px;
    border: 1px solid var(--rule);
    transition: all 0.2s;
}
.popup-card .lesson-item:hover {
    border-color: var(--gold-bd);
    box-shadow: var(--shadow);
}
.popup-card .lesson-item .lesson-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 4px;
}
.popup-card .lesson-item .lesson-num {
    font-family: var(--font-el);
    font-size: 16px;
    font-weight: 700;
    color: var(--gold2);
    background: var(--gold-bg);
    padding: 0 12px;
    border-radius: 30px;
    min-width: 48px;
    text-align: center;
    line-height: 28px;
}
.popup-card .lesson-item .lesson-topic {
    font-size: 16px;
    font-weight: 700;
    color: var(--ink);
}
.popup-card .lesson-item .lesson-detail {
    font-size: 14px;
    color: var(--ink2);
    line-height: 1.6;
    padding-left: 4px;
}
.popup-card .lesson-item .lesson-detail .label {
    font-weight: 600;
    color: var(--ink);
    display: inline-block;
    min-width: 52px;
}
.popup-card .lesson-item .lesson-detail .label-outcome {
    font-weight: 600;
    color: var(--gold2);
    display: inline-block;
    min-width: 52px;
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    body {
        padding: 12px 10px 40px;
    }
    .header {
        padding: 20px 20px 16px;
        flex-direction: column;
        align-items: stretch;
        gap: 12px;
    }
    .header-left h1 {
        font-size: 22px;
    }
    .header-left .sub {
        font-size: 12px;
    }
    .header-right {
        justify-content: space-between;
    }
    .filter-toggle-bar {
        gap: 10px;
    }
    .filter-toggle-btn {
        padding: 6px 16px;
        font-size: 13px;
    }
    .filter-section {
        padding: 14px 16px;
    }
    .filter-section.hidden {
        padding: 0 16px;
    }
    .filter-row {
        gap: 8px 12px;
    }
    .filter-btn {
        padding: 5px 12px;
        font-size: 12px;
    }
    .course-grid {
        grid-template-columns: 1fr;
    }
    .course-grid.list-view .course-card {
        flex-direction: column;
        align-items: stretch;
    }
    .toolbar {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }
    .toolbar-left {
        flex-wrap: wrap;
        justify-content: space-between;
    }
    .view-toggle button {
        padding: 5px 14px;
        font-size: 12px;
    }
    .course-card .top-row {
        flex-wrap: wrap;
    }
    .course-grid.list-view .course-card .top-row .left-tags {
        flex-wrap: wrap;
    }
    .popup-card {
        padding: 20px 18px 18px;
        max-width: 98%;
        max-height: 92vh;
    }
    .popup-card .popup-title {
        font-size: 20px;
    }
    .popup-card .lesson-item {
        padding: 10px 12px;
    }
    .popup-card .lesson-item .lesson-topic {
        font-size: 14px;
    }
    .popup-card .lesson-item .lesson-detail {
        font-size: 13px;
    }
}

@media (max-width: 480px) {
    .header-left .logo {
        font-size: 30px;
    }
    .header-left h1 {
        font-size: 19px;
    }
    .filter-toggle-btn {
        font-size: 12px;
        padding: 5px 14px;
    }
    .filter-btn {
        font-size: 11px;
        padding: 4px 10px;
    }
    .course-card {
        padding: 14px 16px 14px;
    }
    .course-card .course-title {
        font-size: 17px;
    }
    .course-card .course-id {
        font-size: 12px;
        padding: 2px 10px;
    }
    .popup-card .popup-lessons-title {
        font-size: 16px;
    }
    .popup-card .lesson-item .lesson-num {
        font-size: 14px;
        min-width: 40px;
        line-height: 24px;
    }
}

/* ===== 登录/注册 ===== */
.auth-overlay {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.45); backdrop-filter: blur(6px);
    display: flex; align-items: center; justify-content: center;
    z-index: 2000; opacity: 0; visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}
.auth-overlay.active { opacity: 1; visibility: visible; }

.auth-card {
    background: var(--paper); border-radius: 24px; max-width: 420px;
    width: 94%; padding: 32px 28px 28px;
    box-shadow: 0 40px 80px rgba(0,0,0,0.25);
    transform: scale(0.95) translateY(20px);
    transition: transform 0.35s ease;
    position: relative; border: 1px solid var(--rule);
}
.auth-overlay.active .auth-card { transform: scale(1) translateY(0); }

.auth-close {
    position: absolute; top: 12px; right: 16px; background: none;
    border: none; font-size: 24px; color: var(--ink3); cursor: pointer;
    width: 36px; height: 36px; border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    transition: 0.2s;
}
.auth-close:hover { background: var(--paper2); color: var(--ink); }

.auth-header { margin-bottom: 16px; }
.auth-tabs { display: flex; background: var(--paper2); border-radius: 40px; padding: 3px; }
.auth-tab {
    flex: 1; padding: 8px; border: none; background: transparent;
    border-radius: 30px; font-size: 14px; font-weight: 700;
    color: var(--ink3); cursor: pointer; font-family: var(--font-sans);
    transition: 0.2s;
}
.auth-tab.active { background: var(--paper); color: var(--ink); box-shadow: var(--shadow); }

.auth-form { display: none; }
.auth-form.active { display: block; }
.auth-title { font-size: 20px; font-weight: 800; color: var(--ink); margin-bottom: 16px; text-align: center; font-family: var(--font-serif); }

.auth-field { margin-bottom: 14px; }
.auth-field label { display: block; font-size: 13px; font-weight: 600; color: var(--ink2); margin-bottom: 4px; }
.auth-field input {
    width: 100%; padding: 12px 14px; border-radius: 12px;
    border: 1px solid var(--rule); font-size: 14px; outline: none;
    background: var(--paper); font-family: var(--font-sans);
    transition: 0.2s; box-sizing: border-box;
}
.auth-field input:focus { border-color: var(--gold); box-shadow: 0 0 0 3px var(--gold-bg); }
.auth-field select {
    width: 100%; padding: 12px 14px; border-radius: 12px;
    border: 1px solid var(--rule); font-size: 14px; outline: none;
    background: var(--paper); font-family: var(--font-sans);
    transition: 0.2s; box-sizing: border-box; cursor: pointer;
    appearance: auto; color: var(--ink);
}
.auth-field select:focus { border-color: var(--gold); box-shadow: 0 0 0 3px var(--gold-bg); }

.auth-error { font-size: 13px; color: #c0392b; min-height: 20px; margin-bottom: 4px; }
.auth-submit {
    width: 100%; padding: 12px; border: none; border-radius: 30px;
    background: var(--gold); color: #fff; font-size: 15px; font-weight: 700;
    cursor: pointer; font-family: var(--font-sans); transition: 0.2s;
}
.auth-submit:hover { background: var(--gold2); transform: translateY(-1px); }
.auth-submit:active { transform: scale(0.97); }

.auth-btn { transition: background 0.2s; }
.auth-btn.logged-in { background: var(--gold-bg) !important; color: var(--gold2) !important; }

/* ===== 动画 ===== */
@keyframes floatUp {
    0% {
        opacity: 0;
        transform: translateY(16px);
    }
    100% {
        opacity: 1;
        transform: translateY(0);
    }
}
.course-card {
    animation: floatUp 0.4s ease forwards;
}
.course-card:nth-child(2) {
    animation-delay: 0.04s;
}
.course-card:nth-child(3) {
    animation-delay: 0.08s;
}
.course-card:nth-child(4) {
    animation-delay: 0.12s;
}
.course-card:nth-child(5) {
    animation-delay: 0.16s;
}
.course-card:nth-child(6) {
    animation-delay: 0.20s;
}
.course-card:nth-child(7) {
    animation-delay: 0.24s;
}
.course-card:nth-child(8) {
    animation-delay: 0.28s;
}
.course-card:nth-child(9) {
    animation-delay: 0.32s;
}
.course-card:nth-child(10) {
    animation-delay: 0.36s;
}
.course-card:nth-child(11) {
    animation-delay: 0.40s;
}
.course-card:nth-child(12) {
    animation-delay: 0.44s;
}
.course-card:nth-child(13) {
    animation-delay: 0.48s;
}