/*
 * 首页专属样式（hero 轮播 / 公告条 / 学院网格）。
 * 只在 index.html 加载；通用组件一律放 system.css。
 */

/* --- 公告条 ------------------------------------------------------------- */

.announcement-bar {
    border-bottom: 1px solid var(--warning-border);
    background: var(--warning-bg);
}

.announcement {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
    padding: var(--space-3) 0;
    color: var(--warning-fg);
    font-size: var(--text-md);
}

.announcement__main {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    min-width: 0;
}

.announcement__title {
    font-weight: var(--weight-semibold);
    white-space: nowrap;
}

.announcement__content {
    overflow: hidden;
    color: inherit;
    text-overflow: ellipsis;
    white-space: nowrap;
    text-decoration: none;
}

.announcement__content:hover {
    text-decoration: underline;
    text-underline-offset: 2px;
}

.announcement__aside {
    display: flex;
    flex-shrink: 0;
    align-items: center;
    gap: var(--space-3);
    font-size: var(--text-xs);
}

.announcement__dismiss {
    border: 0;
    background: none;
    color: inherit;
    opacity: 0.75;
    cursor: pointer;
}

.announcement__dismiss:hover {
    opacity: 1;
}

/* --- Hero 轮播 ---------------------------------------------------------- */

.home-hero {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 13rem;
    /* 底部多留两档，给轮播指示点让位，避免与搜索框视觉重叠 */
    padding: var(--space-8) var(--space-4) var(--space-16);
    overflow: hidden;
    background-color: var(--neutral-800);
}

.carousel-container {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.carousel-slide {
    position: absolute;
    inset: 0;
    z-index: 1;
    background-position: center;
    background-size: cover;
    opacity: 0;
    visibility: hidden;
    transition: opacity 800ms ease-in, visibility 0s linear 800ms;
}

.carousel-slide.active {
    z-index: 2;
    opacity: 1;
    visibility: visible;
    transition: opacity 800ms ease-out, visibility 0s linear;
}

/*
 * 压暗 + 底部加深的渐变，保证标题与搜索框在任何底图上都达到对比度要求。
 */
.carousel-slide::before {
    position: absolute;
    inset: 0;
    background: linear-gradient(
        180deg,
        rgba(15, 19, 24, 0.4) 0%,
        rgba(15, 19, 24, 0.52) 55%,
        rgba(15, 19, 24, 0.66) 100%
    );
    content: "";
}

.carousel-btn {
    position: absolute;
    top: 50%;
    z-index: 20;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    border: 0;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.22);
    color: var(--neutral-0);
    cursor: pointer;
    transform: translateY(-50%);
    transition: var(--transition-colors);
}

.carousel-btn:hover {
    background: rgba(255, 255, 255, 0.75);
    color: var(--neutral-900);
}

.carousel-btn-prev {
    left: var(--space-6);
}

.carousel-btn-next {
    right: var(--space-6);
}

.carousel-indicators {
    position: absolute;
    bottom: var(--space-2);
    left: 50%;
    z-index: 20;
    display: flex;
    gap: var(--space-2);
    align-items: center;
    /* 内边距扩大整块热区，便于触控操作 */
    padding: var(--space-2) var(--space-3);
    transform: translateX(-50%);
}

.carousel-indicator {
    width: 0.5rem;
    height: 0.5rem;
    padding: 0;
    border: 0;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    transition: background-color var(--duration-base) var(--ease-out),
        transform var(--duration-base) var(--ease-out);
}

.carousel-indicator.active {
    background: var(--neutral-0);
    transform: scale(1.3);
}

/* 轮播暂停按钮：WCAG 2.2.2 要求自动播放内容可停止 */
.carousel-pause {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1.5rem;
    height: 1.5rem;
    margin-left: var(--space-2);
    padding: 0;
    border: 0;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.28);
    color: var(--neutral-0);
    font-size: var(--text-2xs);
    cursor: pointer;
    transition: var(--transition-colors);
}

.carousel-pause:hover {
    background: rgba(255, 255, 255, 0.75);
    color: var(--neutral-900);
}

.home-hero__content {
    position: relative;
    z-index: 10;
    width: 100%;
    max-width: 44rem;
    text-align: center;
}

.home-hero__feature {
    display: flex;
    min-height: 6rem;
    margin: 0 auto var(--space-8);
    align-items: center;
    justify-content: center;
}

.home-hero__site-name {
    margin: 0;
    color: rgba(255, 255, 255, 0.96);
    font-size: var(--text-3xl);
    font-weight: var(--weight-bold);
    letter-spacing: 0;
    text-shadow: 0 1px 8px rgba(0, 0, 0, 0.35);
}

.section--collapsible .section__header {
    gap: var(--space-3);
}

.collapsible-panel[hidden] {
    display: none !important;
}

.home-hero__tagline {
    margin: 0;
    color: rgba(255, 255, 255, 0.92);
    font-size: var(--text-lg);
    text-shadow: 0 1px 8px rgba(0, 0, 0, 0.35);
}

.home-hero__search {
    display: flex;
    align-items: stretch;
    overflow: hidden;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.home-hero__search input {
    flex: 1 1 auto;
    min-width: 0;
    padding: var(--space-4) var(--space-5);
    border: 0;
    background: var(--color-surface);
    color: var(--color-text);
    font-size: var(--text-base);
}

.home-hero__search input:focus {
    outline: none;
}

.home-hero__search:focus-within {
    box-shadow: var(--shadow-lg), 0 0 0 3px rgba(255, 255, 255, 0.55);
}

.home-hero__search button {
    flex-shrink: 0;
    padding: 0 var(--space-6);
    border: 0;
    background: var(--color-btn-primary-bg);
    color: var(--neutral-0);
    font-size: var(--text-base);
    cursor: pointer;
    transition: var(--transition-colors);
}

.home-hero__search button:hover {
    background: var(--color-btn-primary-hover);
}

/* 学期提示：跟在搜索框下方的一行安静文字（未配置学期时不渲染） */
.home-hero__semester {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    margin: var(--space-4) 0 0;
    color: rgba(255, 255, 255, 0.88);
    font-size: var(--text-md);
    text-shadow: 0 1px 6px rgba(0, 0, 0, 0.3);
    font-variant-numeric: tabular-nums;
}

.home-hero__semester i {
    opacity: 0.8;
}

.home-hero__credit {
    padding: var(--space-2) var(--space-4);
    color: var(--color-text-muted);
    font-size: var(--text-xs);
    text-align: right;
}

.home-hero__credit a {
    color: inherit;
}

@media (max-width: 639px) {
    .home-hero {
        min-height: 11rem;
        /* 底部留出轮播指示点的高度 */
        padding: var(--space-6) var(--space-4) var(--space-12);
    }

    .home-hero__tagline {
        font-size: var(--text-base);
    }

    .home-hero__feature {
        min-height: 4rem;
        margin-bottom: var(--space-6);
    }

    .home-hero__search input {
        padding: var(--space-3) var(--space-4);
        font-size: var(--text-md);
    }

    .home-hero__credit {
        text-align: center;
    }
}

/* --- 我的课程面板 -------------------------------------------------------- */

.course-panel__tabs {
    display: flex;
    gap: var(--space-2);
    padding-bottom: var(--space-4);
    overflow-x: auto;
    scrollbar-width: thin;
}

.course-panel__column-title {
    margin: 0 0 var(--space-3);
    color: var(--color-text-secondary);
    font-size: var(--text-md);
    font-weight: var(--weight-semibold);
}

/* --- 资料卡片网格 -------------------------------------------------------- */

.material-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-5);
}

@media (min-width: 768px) {
    .material-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (min-width: 1024px) {
    .material-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

.material-card .card__body {
    padding: var(--space-4) var(--space-5) var(--space-3);
}

.material-card__title {
    /* 固定两行高度，网格里卡片底边对齐 */
    display: -webkit-box;
    min-height: calc(2 * 1.5em);
    margin: 0 0 var(--space-2);
    overflow: hidden;
    font-size: var(--text-base);
    font-weight: var(--weight-semibold);
    line-height: var(--leading-snug);
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.material-card__course {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    margin: 0 0 var(--space-4);
    overflow: hidden;
    color: var(--color-text-muted);
    font-size: var(--text-sm);
    white-space: nowrap;
    text-overflow: ellipsis;
}

.material-card__stats {
    gap: var(--space-4);
}

/* 页脚只留发丝线，不再用灰底把卡片切成两块 */
.material-card__footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-5);
    border-top: 1px solid var(--neutral-100);
}

.material-card__uploader {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    min-width: 0;
    color: var(--color-text-muted);
    font-size: var(--text-sm);
}

/* --- 贡献引导：一条安静的横幅，不做居中大促销区块 -------------------------- */

.contribute {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
    padding: var(--space-5) var(--space-6);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-surface);
}

.contribute__main {
    min-width: 0;
}

.contribute__title {
    margin: 0 0 var(--space-1);
    font-size: var(--text-base);
}

.contribute__text {
    margin: 0;
    color: var(--color-text-muted);
    font-size: var(--text-sm);
}

/* --- 学院网格 ------------------------------------------------------------ */

.department-search {
    max-width: 26rem;
    margin: 0 auto var(--space-6);
}

.department-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-4);
}

@media (min-width: 768px) {
    .department-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

@media (min-width: 1024px) {
    .department-grid {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }
}

.department-card {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-4);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-surface);
    color: var(--color-text);
    text-decoration: none;
    transition: var(--transition-colors), box-shadow var(--duration-base)
        var(--ease-out);
}

.department-card:hover {
    border-color: var(--color-border-strong);
    box-shadow: var(--shadow-md);
}

.department-card__icon {
    display: inline-flex;
    flex: 0 0 2.5rem;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    border-radius: var(--radius-md);
    background: var(--color-accent-soft);
    color: var(--color-accent);
}

.department-card__name {
    min-width: 0;
    font-size: var(--text-md);
    font-weight: var(--weight-medium);
    line-height: var(--leading-snug);
}

/* --- 数据统计 ------------------------------------------------------------ */

.stat-grid {
    display: grid;
    /* auto-fit：列数跟随内容，管理员多出的"当前在线"不会留下空槽 */
    grid-template-columns: repeat(auto-fit, minmax(11rem, 1fr));
    gap: 1px;
    overflow: hidden;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-border);
}

/* 统计数字彩色分类（与 profile stat-tile 调色板一致，文档化例外） */
.stat__value--users {
    color: #1d4ed8;
}

.stat__value--materials {
    color: #15803d;
}

.stat__value--downloads {
    color: #7e22ce;
}

.stat__value--online {
    color: #c2410c;
}


/* 首页统计数字暗色变体（深底上需要更高的明度） */
:root[data-theme="dark"] .stat__value--users {
    color: #7ba7f5;
}

:root[data-theme="dark"] .stat__value--materials {
    color: #4ecb77;
}

:root[data-theme="dark"] .stat__value--downloads {
    color: #b97ae8;
}

:root[data-theme="dark"] .stat__value--online {
    color: #f07f3e;
}