/* ==========================================================================
   德和堂 DEHE OS · 官网样式
   --------------------------------------------------------------------------
   设计参考：iF Design — AI-Powered Educational Platform
   特征：明亮白底 + 红色点缀 + 卡片化信息板 + 大量留白 + 中性冷灰底色
   规范：移动端优先（320 / 390 / 768 / 1440），系统中文字体，无第三方大字体
   ========================================================================== */

:root {
    /* 主色：品牌红（点缀用） */
    --brand-red: #E8384F;
    --brand-red-dark: #C72840;
    --brand-red-soft: #FDEEF0;
    --brand-red-line: #F7CBD2;

    /* 中性：冷灰蓝基调 */
    --ink-900: #14181F;
    --ink-800: #1F252E;
    --ink-700: #333B47;
    --ink-600: #4E5764;
    --ink-500: #6B7482;
    --ink-400: #949CA8;
    --ink-300: #C2C8D1;
    --ink-200: #E2E6EB;
    --ink-100: #F0F2F5;
    --ink-050: #F7F8FA;

    --surface: #FFFFFF;
    --surface-alt: #F7F8FA;
    --surface-panel: #FBFCFD;

    /* 语义色 */
    --ok: #1F9D6B;
    --ok-soft: #E8F6F0;
    --warn: #C77A12;
    --warn-soft: #FDF3E3;
    --danger: #C3354A;
    --danger-soft: #FCEBED;
    --info: #2D6FBF;
    --info-soft: #EAF2FC;

    /* 排版 */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC",
        "Noto Sans CJK SC", "WenQuanYi Micro Hei", sans-serif;
    --font-serif: "Songti SC", "SimSun", "Source Han Serif SC",
        "Noto Serif CJK SC", serif;

    /* 间距 */
    --sp-1: 4px;
    --sp-2: 8px;
    --sp-3: 12px;
    --sp-4: 16px;
    --sp-5: 24px;
    --sp-6: 32px;
    --sp-7: 48px;
    --sp-8: 64px;
    --sp-9: 96px;

    /* 圆角 */
    --r-sm: 6px;
    --r-md: 10px;
    --r-lg: 16px;
    --r-xl: 24px;
    --r-full: 999px;

    /* 阴影 */
    --shadow-xs: 0 1px 2px rgba(20, 24, 31, .05);
    --shadow-sm: 0 2px 8px rgba(20, 24, 31, .06);
    --shadow-md: 0 8px 24px rgba(20, 24, 31, .08);
    --shadow-lg: 0 20px 48px rgba(20, 24, 31, .12);

    --container: 1440px;
    --header-h: 64px;
}

/* ==========================================================================
   基础
   ========================================================================== */

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

html {
    -webkit-text-size-adjust: 100%;
    scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after {
        animation-duration: .01ms !important;
        transition-duration: .01ms !important;
    }
}

body {
    margin: 0;
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.75;
    color: var(--ink-800);
    background: var(--surface);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img { max-width: 100%; height: auto; display: block; }

a {
    color: inherit;
    text-decoration: none;
    transition: color .18s ease;
}

a:hover { color: var(--brand-red); }

h1, h2, h3, h4 {
    margin: 0;
    line-height: 1.3;
    color: var(--ink-900);
    font-weight: 700;
    letter-spacing: -.01em;
}

p { margin: 0; }

ul, ol { margin: 0; padding: 0; list-style: none; }

button { font-family: inherit; cursor: pointer; }

:focus-visible {
    outline: 2px solid var(--brand-red);
    outline-offset: 3px;
    border-radius: 3px;
}

::selection { background: var(--brand-red-soft); color: var(--brand-red-dark); }

/* 屏幕阅读器专用 */
.sr-only {
    position: absolute; width: 1px; height: 1px;
    padding: 0; margin: -1px; overflow: hidden;
    clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}

.skip-link {
    position: absolute; left: -9999px; top: 0; z-index: 200;
    background: var(--brand-red); color: #fff;
    padding: var(--sp-3) var(--sp-4);
    border-radius: 0 0 var(--r-sm) 0;
}
.skip-link:focus { left: 0; color: #fff; }

/* ==========================================================================
   布局容器
   ========================================================================== */

.container {
    width: 100%;
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 var(--sp-5);
}

.section { padding: var(--sp-8) 0; }
.section--tight { padding: var(--sp-7) 0; }
.section--alt { background: var(--surface-alt); }
.section--panel { background: var(--surface-panel); }

@media (max-width: 767px) {
    .section { padding: var(--sp-7) 0; }
    .container { padding: 0 var(--sp-4); }
}

/* ==========================================================================
   标题组
   ========================================================================== */

.section-head { margin-bottom: var(--sp-6); }

.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: var(--sp-2);
    font-size: 13px;
    font-weight: 600;
    letter-spacing: .08em;
    color: var(--brand-red);
    text-transform: uppercase;
    margin-bottom: var(--sp-3);
}

.eyebrow::before {
    content: "";
    width: 18px; height: 2px;
    background: var(--brand-red);
    border-radius: 2px;
}

.section-title {
    font-size: clamp(24px, 4vw, 36px);
    margin-bottom: var(--sp-3);
}

.section-lead {
    font-size: 16px;
    color: var(--ink-600);
    max-width: 68ch;
    line-height: 1.85;
}

.section-head--center { text-align: center; }
.section-head--center .section-lead { margin-left: auto; margin-right: auto; }
.section-head--center .eyebrow { justify-content: center; }

/* ==========================================================================
   按钮
   ========================================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--sp-2);
    padding: 13px 26px;
    border-radius: var(--r-full);
    font-size: 15px;
    font-weight: 600;
    line-height: 1;
    border: 1px solid transparent;
    transition: background .18s ease, color .18s ease, border-color .18s ease, transform .18s ease, box-shadow .18s ease;
    white-space: nowrap;
}

.btn:active { transform: translateY(1px); }

.btn--primary {
    background: var(--brand-red);
    color: #fff;
    box-shadow: 0 4px 14px rgba(232, 56, 79, .24);
}
.btn--primary:hover { background: var(--brand-red-dark); color: #fff; }

.btn--ghost {
    background: transparent;
    color: var(--ink-800);
    border-color: var(--ink-200);
}
.btn--ghost:hover { border-color: var(--ink-900); color: var(--ink-900); background: var(--surface); }

.btn--light {
    background: rgba(255, 255, 255, .96);
    color: var(--ink-900);
}
.btn--light:hover { background: #fff; color: var(--brand-red); }

.btn--sm { padding: 9px 18px; font-size: 14px; }
.btn--block { width: 100%; }

/* 文字链接 */
.link-arrow {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-weight: 600;
    color: var(--ink-800);
    font-size: 15px;
}
.link-arrow::after {
    content: "→";
    transition: transform .2s ease;
}
.link-arrow:hover { color: var(--brand-red); }
.link-arrow:hover::after { transform: translateX(3px); }

/* ==========================================================================
   标签 / 徽章
   ========================================================================== */

.tag {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 4px 11px;
    border-radius: var(--r-full);
    font-size: 12px;
    font-weight: 600;
    line-height: 1.6;
    background: var(--ink-100);
    color: var(--ink-600);
    white-space: nowrap;
}

.tag--red { background: var(--brand-red-soft); color: var(--brand-red-dark); }
.tag--outline { background: transparent; border: 1px solid var(--ink-200); color: var(--ink-600); }
.tag--ok { background: var(--ok-soft); color: var(--ok); }
.tag--warn { background: var(--warn-soft); color: var(--warn); }
.tag--info { background: var(--info-soft); color: var(--info); }

/* 课程级别徽章 */
.level-badge {
    display: inline-flex;
    align-items: baseline;
    gap: 6px;
    font-weight: 700;
    color: var(--brand-red);
    letter-spacing: .02em;
}
.level-badge__code {
    font-size: 13px;
    padding: 2px 8px;
    border-radius: var(--r-sm);
    background: var(--brand-red-soft);
    border: 1px solid var(--brand-red-line);
}

/* ==========================================================================
   顶部导航
   ========================================================================== */

.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, .92);
    backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid var(--ink-100);
}

.site-header__inner {
    height: var(--header-h);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--sp-4);
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    flex-shrink: 0;
}

.brand__mark {
    width: 34px; height: 34px;
    border-radius: 9px;
    background: var(--brand-red);
    color: #fff;
    display: grid;
    place-items: center;
    font-weight: 800;
    font-size: 16px;
    letter-spacing: -.02em;
    flex-shrink: 0;
}

.brand__text { display: flex; flex-direction: column; line-height: 1.2; }

.brand__name {
    font-size: 15px;
    font-weight: 700;
    color: var(--ink-900);
    letter-spacing: -.01em;
}

.brand__tag {
    font-size: 11px;
    color: var(--ink-500);
    letter-spacing: .04em;
}

.nav-toggle {
    display: none;
    width: 42px; height: 42px;
    border: 1px solid var(--ink-200);
    border-radius: var(--r-md);
    background: var(--surface);
    align-items: center;
    justify-content: center;
}

.nav-toggle__bars { display: block; width: 18px; height: 12px; position: relative; }
.nav-toggle__bars::before, .nav-toggle__bars::after,
.nav-toggle__bars span {
    content: ""; position: absolute; left: 0;
    width: 100%; height: 2px; background: var(--ink-800);
    border-radius: 2px;
    transition: transform .22s ease, opacity .18s ease;
}
.nav-toggle__bars span { top: 5px; }
.nav-toggle__bars::before { top: 0; }
.nav-toggle__bars::after { top: 10px; }

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { transform: translateY(-5px) rotate(-45deg); }

.site-nav { display: flex; align-items: center; gap: var(--sp-1); }

.site-nav__link {
    padding: 8px 13px;
    border-radius: var(--r-md);
    font-size: 14.5px;
    font-weight: 500;
    color: var(--ink-700);
    white-space: nowrap;
}
.site-nav__link:hover { background: var(--ink-050); color: var(--ink-900); }
.site-nav__link.is-active { color: var(--brand-red); font-weight: 600; }

.site-header__cta { display: flex; align-items: center; gap: var(--sp-3); }

@media (max-width: 1023px) {
    .nav-toggle { display: inline-flex; }

    .site-nav {
        position: fixed;
        inset: var(--header-h) 0 auto 0;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        background: var(--surface);
        border-bottom: 1px solid var(--ink-100);
        box-shadow: var(--shadow-md);
        padding: var(--sp-3) var(--sp-4) var(--sp-5);
        max-height: calc(100vh - var(--header-h));
        overflow-y: auto;
        transform: translateY(-8px);
        opacity: 0;
        visibility: hidden;
        transition: opacity .2s ease, transform .2s ease, visibility .2s;
    }

    .site-nav.is-open { transform: translateY(0); opacity: 1; visibility: visible; }

    .site-nav__link {
        padding: 13px 4px;
        border-bottom: 1px solid var(--ink-100);
        border-radius: 0;
        font-size: 15.5px;
    }

    .site-header__cta .btn { display: none; }
}

@media (min-width: 1024px) {
    .site-nav__mobile-cta { display: none; }
}

/* ==========================================================================
   首屏 Hero
   ========================================================================== */

.hero {
    position: relative;
    overflow: hidden;
    background:
        radial-gradient(900px 460px at 88% -8%, var(--brand-red-soft) 0%, transparent 62%),
        radial-gradient(700px 420px at 6% 8%, #EEF3FA 0%, transparent 58%),
        var(--surface);
    padding: clamp(48px, 9vw, 104px) 0 clamp(40px, 7vw, 84px);
}

/*
 * V3.2：首屏主视觉整幅铺满，文字叠加在图片左侧
 *
 * - 背景图绝对定位铺满整个 hero，接近全屏但不裁切人物
 * - 左侧渐变遮罩保证文字可读（不把文字直接压在人物上）
 * - 移动端恢复常规流式布局：文字在上、图片在下
 */
.hero--bleed {
    padding: 0;
    min-height: clamp(520px, calc(100svh - 88px), 860px);
    display: flex;
    align-items: stretch;
    background: var(--ink-900);
}

.hero--bleed .hero__inner {
    position: relative;
    z-index: 2;
    display: grid;
    grid-template-columns: 1fr;
    align-items: center;
    gap: var(--sp-7);
    /* 两侧各留 10px，视觉接近全宽但保留呼吸感 */
    width: calc(100% - 20px);
    max-width: none;
    margin-inline: auto;
    padding: clamp(48px, 7vw, 88px) clamp(16px, 3.4vw, 56px);
}

.hero--bleed .hero__copy {
    max-width: 720px;
    /* 文字必须明确高于绝对定位的背景图 */
    position: relative;
    z-index: 3;
}

.hero--bleed .hero__title {
    font-size: clamp(32px, 3.9vw, 58px);
    max-width: 15ch;
}

.hero--bleed .hero__visual {
    position: absolute;
    inset: 0;
    z-index: 0;
    margin: 0;
    border-radius: 0;
    overflow: hidden;
}

.hero--bleed .hero__visual figure,
.hero--bleed .hero__visual img {
    width: 100%;
    height: 100%;
    margin: 0;
    display: block;
}

.hero--bleed .hero__visual img {
    object-fit: cover;
    object-position: center 38%;
}

/* 左侧渐变遮罩：让文字有独立可读区，人物保留在右侧 */
.hero--bleed .hero__visual::after {
    content: "";
    position: absolute;
    inset: 0;
    background:
        linear-gradient(96deg,
            rgba(8, 11, 17, .94) 0%,
            rgba(8, 11, 17, .90) 22%,
            rgba(8, 11, 17, .78) 36%,
            rgba(8, 11, 17, .48) 50%,
            rgba(8, 11, 17, .18) 64%,
            rgba(8, 11, 17, .04) 76%,
            rgba(8, 11, 17, 0) 88%);
    pointer-events: none;
}

.hero--bleed .hero__cover {
    aspect-ratio: auto;
    height: 100%;
    margin: 0;
    border: 0;
    border-radius: 0;
    box-shadow: none;
    background: var(--ink-900);
}

.hero--bleed .hero__cover::after { display: none; }

.hero--bleed .hero__cover figcaption {
    position: absolute;
    right: 16px;
    bottom: 16px;
    left: auto;
    z-index: 3;
}

.hero--bleed .hero__title { color: #fff; }
.hero--bleed .hero__subtitle { color: rgba(255, 255, 255, .88); }
.hero--bleed .hero__supporting { color: rgba(255, 255, 255, .78); }

.hero--bleed .hero__eyebrow {
    background: rgba(255, 255, 255, .12);
    border-color: rgba(255, 255, 255, .3);
    color: #fff;
    backdrop-filter: blur(4px);
}

.hero--bleed .hero__keyword {
    background: rgba(255, 255, 255, .14);
    border-color: rgba(255, 255, 255, .26);
    color: rgba(255, 255, 255, .94);
}

.hero--bleed .btn--ghost {
    border-color: rgba(255, 255, 255, .5);
    color: #fff;
}

.hero--bleed .btn--ghost:hover {
    background: rgba(255, 255, 255, .14);
}

/* 桌面端：文字占左侧，图片整幅铺底 */
@media (min-width: 1024px) {
    .hero--bleed .hero__inner {
        grid-template-columns: minmax(0, 52fr) minmax(0, 48fr);
    }
    .hero--bleed .hero__copy { grid-column: 1; }
}

@media (max-width: 1023px) {
    /* 平板/手机：恢复流式，文字在上、图片在下 */
    .hero--bleed {
        min-height: auto;
        display: block;
        padding: 0;
        background: var(--surface);
    }

    .hero--bleed .hero__inner {
        display: block;
        width: calc(100% - 20px);
        padding: clamp(36px, 8vw, 56px) clamp(16px, 5vw, 32px) 0;
    }

    .hero--bleed .hero__copy { max-width: none; }

    .hero--bleed .hero__visual {
        position: relative;
        inset: auto;
        margin: clamp(24px, 5vw, 36px) 0 0;
        border-radius: var(--r-lg);
        aspect-ratio: 16 / 9;
    }

    .hero--bleed .hero__visual::after {
        background: linear-gradient(180deg, rgba(10, 14, 20, .55) 0%, rgba(10, 14, 20, .06) 38%);
    }

    .hero--bleed .hero__cover {
        height: 100%;
        border-radius: var(--r-lg);
    }

    .hero--bleed .hero__title { color: var(--ink-900); }
    .hero--bleed .hero__subtitle { color: var(--ink-600); }
    .hero--bleed .hero__supporting { color: var(--ink-600); }

    .hero--bleed .hero__eyebrow {
        background: var(--surface);
        border-color: var(--brand-red-line);
        color: var(--brand-red);
    }

    .hero--bleed .hero__keyword {
        background: var(--ink-050);
        border-color: var(--ink-100);
        color: var(--ink-700);
    }
}

.hero__inner {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--sp-7);
    align-items: center;
    min-width: 0;
}

/*
 * V3.1 / V3.2 桌面端首屏分栏
 *
 * 左侧 45% 文字，右侧 55% 主视觉。
 * 主视觉宽度显著大于文字区，保证在 1920×1080 下形成完整首屏。
 */
@media (min-width: 1024px) {
    .hero__inner {
        grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
        gap: clamp(32px, 4vw, 72px);
    }
}

/* 超宽屏（≥1600px）主视觉进一步放大 */
@media (min-width: 1600px) {
    .hero__inner {
        grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
    }
}

.hero__copy { min-width: 0; }
.hero__visual { min-width: 0; }

.hero__eyebrow {
    display: inline-flex;
    align-items: center;
    gap: var(--sp-2);
    padding: 6px 14px;
    border-radius: var(--r-full);
    background: var(--surface);
    border: 1px solid var(--brand-red-line);
    color: var(--brand-red-dark);
    font-size: 13px;
    font-weight: 600;
    box-shadow: var(--shadow-xs);
    margin-bottom: var(--sp-4);
}

.hero__title {
    font-size: clamp(30px, 5.6vw, 54px);
    line-height: 1.22;
    letter-spacing: -.02em;
    margin-bottom: var(--sp-4);
}

.hero__title em {
    font-style: normal;
    color: var(--brand-red);
}

.hero__subtitle {
    font-size: clamp(16px, 2vw, 19px);
    color: var(--ink-600);
    max-width: 52ch;
    margin-bottom: var(--sp-5);
    line-height: 1.8;
}

.hero__supporting {
    font-size: clamp(14px, 1.1vw, 15.5px);
    color: var(--ink-600);
    max-width: 46ch;
    margin-bottom: var(--sp-5);
    line-height: 1.85;
}

.hero__keywords {
    display: flex;
    flex-wrap: wrap;
    gap: var(--sp-2);
    margin-bottom: var(--sp-6);
}

.hero__keyword {
    padding: 7px 15px;
    border-radius: var(--r-full);
    background: var(--surface);
    border: 1px solid var(--ink-200);
    font-size: 13.5px;
    font-weight: 600;
    color: var(--ink-700);
    box-shadow: var(--shadow-xs);
}

.hero__actions { display: flex; flex-wrap: wrap; gap: var(--sp-3); }

/* 首屏右侧视觉板 */
.hero__visual {
    position: relative;
    border-radius: var(--r-xl);
    overflow: hidden;
    background: var(--surface);
    border: 1px solid var(--ink-100);
    box-shadow: var(--shadow-lg);
    padding: var(--sp-5);
}

.hero__visual::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
        radial-gradient(520px 300px at 80% 0%, var(--brand-red-soft), transparent 68%),
        linear-gradient(160deg, #FAFBFC, #F2F4F7);
    z-index: 0;
}

.hero__panel {
    position: relative;
    z-index: 1;
    background: rgba(255, 255, 255, .92);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-lg);
    padding: var(--sp-4) var(--sp-5);
    box-shadow: var(--shadow-sm);
    margin-bottom: var(--sp-3);
}
.hero__panel:last-child { margin-bottom: 0; }

.hero__panel-label {
    font-size: 11.5px;
    font-weight: 700;
    letter-spacing: .1em;
    color: var(--brand-red);
    text-transform: uppercase;
    margin-bottom: var(--sp-2);
}

.hero__panel-title { font-size: 16px; margin-bottom: 6px; }
.hero__panel-text { font-size: 13.5px; color: var(--ink-600); line-height: 1.7; }

.hero__chips { display: flex; flex-wrap: wrap; gap: 6px; margin-top: var(--sp-3); }
.hero__chip {
    font-size: 12px;
    padding: 4px 10px;
    border-radius: var(--r-sm);
    background: var(--ink-050);
    border: 1px solid var(--ink-100);
    color: var(--ink-600);
}

/* ==========================================================================
   卡片
   ========================================================================== */

.card {
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-lg);
    padding: var(--sp-5);
    transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
}

a.card:hover, .card--hover:hover {
    border-color: var(--brand-red-line);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.grid { display: grid; gap: var(--sp-4); }
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.grid--4 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }

/*
 * V3.2：首页四大课程卡片必须四列同排
 *
 * grid--4 使用 auto-fit，在宽容器下会因最小宽度不足而让第四张卡片换行。
 * 此处显式指定四列，确保 1440px 容器内四张卡片同排。
 */
.track-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
}

@media (max-width: 1279px) {
    .track-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 767px) {
    .track-grid { grid-template-columns: 1fr; }
}

/*
 * V3.2：作品馆「教学流程示意」卡片
 *
 * 明确标注为教学流程示意，不得被误认为学生作品。
 */
.flow-card {
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.flow-card__cover {
    position: relative;
    aspect-ratio: 16 / 9;
    overflow: hidden;
    background: var(--ink-050);
}

.flow-card__img {
    width: 100%;
    height: 100%;
    margin: 0;
}

.flow-card__img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center 40%;
    display: block;
}

.flow-card__img figcaption {
    position: absolute;
    right: 10px;
    top: 10px;
    z-index: 3;
}

.flow-card__body {
    padding: 18px 20px 20px;
}

.flow-card__no {
    display: block;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: .1em;
    color: var(--brand-red);
    margin-bottom: 4px;
}

.flow-card__name {
    font-size: 17px;
    margin-bottom: 8px;
}

.flow-card__desc {
    font-size: 13.5px;
    line-height: 1.75;
    color: var(--ink-600);
    margin-bottom: 12px;
}

.flow-card__badge {
    display: inline-block;
    padding: 3px 10px;
    font-size: 11.5px;
    letter-spacing: .04em;
    color: var(--ink-600);
    background: var(--ink-050);
    border: 1px solid var(--ink-100);
    border-radius: 999px;
}

/* V3.2：未审核文章卡片（不可点击） */
.post-card--pending {
    background: var(--surface);
    border: 1px dashed var(--ink-150);
    box-shadow: none;
    cursor: default;
}

.post-card--pending .post-card__title {
    color: var(--ink-800);
}

.post-card__pending-tag {
    font-size: 11.5px;
    color: var(--ink-400);
}

/*
 * V3.2：家长分享卡（带独立封面图）
 *
 * 提供复制文案、查看图片入口；不设公开投稿与评论。
 */
.share-card {
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: transform .18s ease, box-shadow .18s ease;
}

.share-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.share-card__cover {
    position: relative;
    aspect-ratio: 16 / 9;
    overflow: hidden;
    background: var(--ink-050);
}

.share-card__img {
    width: 100%;
    height: 100%;
    margin: 0;
}

.share-card__img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center 40%;
    display: block;
}

.share-card__img figcaption {
    position: absolute;
    right: 10px;
    top: 10px;
    z-index: 3;
}

.share-card__body {
    padding: 18px 20px 20px;
}

.share-card__title {
    font-size: 17px;
    margin-bottom: 8px;
}

.share-card__desc {
    font-size: 13.5px;
    line-height: 1.75;
    color: var(--ink-600);
    margin-bottom: 16px;
}

.share-card__actions {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
}

.quick-section {
    padding: clamp(24px, 3vw, 40px) 0;
    border-bottom: 1px solid var(--ink-100);
}

.quick-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: clamp(12px, 1.4vw, 20px);
}

.quick-card {
    position: relative;
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: 12px;
    padding: 16px 18px;
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-left: 3px solid var(--brand-red);
    border-radius: var(--r-md);
    transition: border-color .18s ease, transform .18s ease, box-shadow .18s ease;
}

.quick-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.quick-card--amber { border-left-color: #C8862B; }
.quick-card--teal { border-left-color: #1E8A7A; }
.quick-card--indigo { border-left-color: #4A5BA8; }

.quick-card__no {
    font-size: 11px;
    font-weight: 700;
    letter-spacing: .08em;
    color: var(--ink-400);
}

.quick-card__name {
    font-size: 16px;
    font-weight: 700;
    color: var(--ink-900);
    line-height: 1.4;
}

.quick-card__desc {
    display: none;
    font-size: 13px;
    color: var(--ink-500);
    line-height: 1.6;
}

.quick-card__arrow {
    font-size: 15px;
    color: var(--ink-400);
    transition: transform .18s ease, color .18s ease;
}

.quick-card:hover .quick-card__arrow {
    transform: translateX(3px);
    color: var(--brand-red);
}

@media (min-width: 1440px) {
    .quick-card { grid-template-columns: auto 1fr; grid-template-areas: "no name" ". desc"; row-gap: 4px; }
    .quick-card__no { grid-area: no; align-self: start; }
    .quick-card__name { grid-area: name; }
    .quick-card__desc { grid-area: desc; display: block; }
    .quick-card__arrow { position: absolute; right: 16px; top: 50%; transform: translateY(-50%); }
    .quick-card:hover .quick-card__arrow { transform: translate(3px, -50%); }
}

@media (max-width: 1023px) {
    .quick-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 767px) {
    .quick-grid { grid-template-columns: 1fr; }
    .quick-card { grid-template-columns: auto 1fr auto; }
    .quick-card__desc { display: block; grid-column: 2 / -1; }
}

/* 能力卡 */
.ability-card {
    position: relative;
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-lg);
    padding: var(--sp-5);
    overflow: hidden;
    transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
}

.ability-card::after {
    content: "";
    position: absolute;
    left: 0; top: 0; bottom: 0;
    width: 3px;
    background: var(--brand-red);
    transform: scaleY(0);
    transform-origin: top;
    transition: transform .25s ease;
}

.ability-card:hover { border-color: var(--brand-red-line); box-shadow: var(--shadow-md); transform: translateY(-2px); }
.ability-card:hover::after { transform: scaleY(1); }

.ability-card__code {
    font-size: 11.5px;
    font-weight: 700;
    letter-spacing: .1em;
    color: var(--brand-red);
    margin-bottom: var(--sp-2);
}

.ability-card__name {
    font-size: 20px;
    margin-bottom: 3px;
}

.ability-card__subtitle {
    font-size: 13px;
    font-weight: 600;
    color: var(--ink-500);
    margin-bottom: var(--sp-3);
}

.ability-card__desc {
    font-size: 14.5px;
    color: var(--ink-600);
    line-height: 1.75;
}

/* 课程级别卡 */
.level-card {
    position: relative;
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-lg);
    overflow: hidden;
    transition: border-color .2s ease, box-shadow .2s ease;
}

.level-card:hover { border-color: var(--brand-red-line); box-shadow: var(--shadow-md); }

.level-card__head {
    padding: var(--sp-5);
    border-bottom: 1px solid var(--ink-100);
    background: linear-gradient(180deg, var(--surface-panel), var(--surface));
}

.level-card__code {
    display: inline-block;
    font-size: 12px;
    font-weight: 800;
    letter-spacing: .06em;
    color: #fff;
    background: var(--brand-red);
    padding: 3px 10px;
    border-radius: var(--r-sm);
    margin-bottom: var(--sp-3);
}

.level-card__title { font-size: 21px; margin-bottom: 6px; }
.level-card__tagline { font-size: 14px; color: var(--ink-600); }
.level-card__body { padding: var(--sp-5); }

.level-card__summary {
    font-size: 14.5px;
    color: var(--ink-600);
    line-height: 1.8;
    margin-bottom: var(--sp-4);
}

.module-list { display: flex; flex-direction: column; gap: var(--sp-2); }

.module-item {
    display: flex;
    align-items: flex-start;
    gap: var(--sp-3);
    padding: 10px 12px;
    background: var(--ink-050);
    border-radius: var(--r-md);
    border: 1px solid var(--ink-100);
}

.module-item__no {
    font-size: 11.5px;
    font-weight: 700;
    color: var(--brand-red);
    background: var(--surface);
    border: 1px solid var(--brand-red-line);
    border-radius: var(--r-sm);
    padding: 2px 7px;
    flex-shrink: 0;
    margin-top: 2px;
}

.module-item__name { font-size: 14.5px; font-weight: 600; color: var(--ink-800); }
.module-item__desc { font-size: 13px; color: var(--ink-500); line-height: 1.65; margin-top: 2px; }

/* 旗舰课程卡 */
.flagship {
    background: var(--surface);
    border: 1px solid var(--brand-red-line);
    border-radius: var(--r-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.flagship__bar {
    background: linear-gradient(120deg, var(--brand-red), var(--brand-red-dark));
    color: #fff;
    padding: var(--sp-4) var(--sp-5);
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--sp-3);
}

.flagship__label {
    font-size: 12px;
    font-weight: 700;
    letter-spacing: .12em;
    text-transform: uppercase;
    opacity: .92;
}

.flagship__status {
    font-size: 12.5px;
    font-weight: 700;
    background: rgba(255, 255, 255, .2);
    border: 1px solid rgba(255, 255, 255, .35);
    padding: 4px 12px;
    border-radius: var(--r-full);
}

.flagship__body { padding: var(--sp-5); }

/*
 * V3.2：DH-201 旗舰项目改为左右分栏
 *
 * 左侧课程介绍，右侧项目情境图；
 * 避免纯文字大框的单调布局。
 */
.flagship--split {
    display: grid;
    grid-template-columns: 1fr;
}

@media (min-width: 1024px) {
    .flagship--split {
        grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
        align-items: stretch;
    }
}

.flagship--split .flagship__body {
    padding: clamp(24px, 3vw, 40px);
}

.flagship__visual {
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    min-height: 260px;
    background: var(--ink-100);
    overflow: hidden;
}

.flagship__cover {
    position: absolute;
    inset: 0;
    margin: 0;
    border-radius: 0;
    overflow: hidden;
}

.flagship__cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center 42%;
    display: block;
}

.flagship__cover figcaption {
    position: absolute;
    right: 12px;
    top: 12px;
    z-index: 3;
}

.flagship__visual-note {
    position: relative;
    z-index: 2;
    margin: 0;
    padding: 16px 18px;
    font-size: 13px;
    line-height: 1.7;
    color: rgba(255, 255, 255, .92);
    background: linear-gradient(180deg, rgba(8, 11, 17, 0), rgba(8, 11, 17, .78));
}

.flagship__visual-badge {
    display: inline-block;
    margin-left: 6px;
    padding: 1px 8px;
    font-size: 11px;
    border-radius: 999px;
    background: rgba(255, 255, 255, .16);
    border: 1px solid rgba(255, 255, 255, .3);
}

.flagship__sub-title {
    font-size: 15px;
    margin: 20px 0 12px;
}

/*
 * V3.2：六阶段横向时间轴
 *
 * 发现问题 → 整理资料 → AI协作 → 核查修改 → 完成作品 → 成果表达
 */
.timeline {
    display: grid;
    grid-template-columns: repeat(6, minmax(0, 1fr));
    gap: 0;
    margin-top: var(--sp-6);
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-lg);
    overflow: hidden;
}

.timeline__step {
    position: relative;
    padding: 20px 18px 22px;
    border-right: 1px solid var(--ink-100);
}

.timeline__step:last-child { border-right: 0; }

.timeline__step::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    height: 3px;
    background: var(--brand-red);
    opacity: .8;
}

.timeline__no {
    display: block;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: .1em;
    color: var(--brand-red);
    margin-bottom: 6px;
}

.timeline__name {
    display: block;
    font-size: 16px;
    font-weight: 700;
    color: var(--ink-900);
    margin-bottom: 6px;
}

.timeline__desc {
    display: block;
    font-size: 12.5px;
    line-height: 1.7;
    color: var(--ink-500);
}

@media (max-width: 1279px) {
    .timeline { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .timeline__step:nth-child(3n) { border-right: 0; }
    .timeline__step:nth-child(-n+3) { border-bottom: 1px solid var(--ink-100); }
}

@media (max-width: 767px) {
    .timeline { grid-template-columns: 1fr; }
    .timeline__step { border-right: 0; border-bottom: 1px solid var(--ink-100); }
    .timeline__step:last-child { border-bottom: 0; }
}

.flagship__title { font-size: clamp(21px, 3vw, 28px); margin-bottom: var(--sp-2); }
.flagship__summary {
    font-size: 15px;
    color: var(--ink-600);
    line-height: 1.85;
    margin-bottom: var(--sp-4);
}

.flagship__meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--sp-2);
    margin-bottom: var(--sp-4);
}

.deliverable-list {
    display: grid;
    gap: var(--sp-2);
    margin-bottom: var(--sp-4);
}

.deliverable-item {
    display: flex;
    align-items: center;
    gap: var(--sp-3);
    font-size: 14.5px;
    color: var(--ink-700);
    padding: 9px 14px;
    background: var(--ink-050);
    border-radius: var(--r-md);
    border: 1px solid var(--ink-100);
}

.deliverable-item::before {
    content: "";
    width: 6px; height: 6px;
    border-radius: 50%;
    background: var(--brand-red);
    flex-shrink: 0;
}

.notice {
    display: flex;
    gap: var(--sp-3);
    padding: var(--sp-4);
    border-radius: var(--r-md);
    background: var(--warn-soft);
    border: 1px solid #F0DCB4;
    font-size: 13.5px;
    color: #7A5310;
    line-height: 1.7;
}

.notice--info { background: var(--info-soft); border-color: #C9DDF5; color: #1B4C86; }
.notice--ok { background: var(--ok-soft); border-color: #BFE5D5; color: #14664A; }

/* ==========================================================================
   文章卡
   ========================================================================== */

.post-card {
    display: flex;
    flex-direction: column;
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-lg);
    overflow: hidden;
    transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
    height: 100%;
}

.post-card:hover { border-color: var(--brand-red-line); box-shadow: var(--shadow-md); transform: translateY(-2px); }

.post-card__cover {
    aspect-ratio: 16 / 10;
    background: linear-gradient(135deg, var(--ink-100), var(--ink-050));
    display: grid;
    place-items: center;
    position: relative;
    overflow: hidden;
}

.post-card__cover img { width: 100%; height: 100%; object-fit: cover; }

.post-card__cover-label {
    font-size: 12px;
    font-weight: 600;
    color: var(--ink-400);
    letter-spacing: .06em;
}

.post-card__body { padding: var(--sp-4) var(--sp-5) var(--sp-5); display: flex; flex-direction: column; flex: 1; }

.post-card__meta {
    display: flex;
    align-items: center;
    gap: var(--sp-2);
    margin-bottom: var(--sp-2);
    font-size: 12.5px;
    color: var(--ink-400);
    flex-wrap: wrap;
}

.post-card__title {
    font-size: 17px;
    line-height: 1.5;
    margin-bottom: var(--sp-2);
}

.post-card__excerpt {
    font-size: 14px;
    color: var(--ink-600);
    line-height: 1.75;
    margin-bottom: var(--sp-4);
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.post-card__foot { margin-top: auto; }

/* ==========================================================================
   作品卡
   ========================================================================== */

.work-card {
    display: flex;
    flex-direction: column;
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-lg);
    overflow: hidden;
    transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
    height: 100%;
}

.work-card:hover { border-color: var(--brand-red-line); box-shadow: var(--shadow-md); transform: translateY(-2px); }

.work-card__cover {
    aspect-ratio: 4 / 3;
    background: linear-gradient(135deg, #F1F3F6, #E8EBF0);
    display: grid;
    place-items: center;
    position: relative;
}

.work-card__alias {
    font-size: 12.5px;
    font-weight: 700;
    color: var(--ink-400);
    letter-spacing: .1em;
}

.work-card__body { padding: var(--sp-4) var(--sp-5) var(--sp-5); }

.work-card__title { font-size: 17px; margin-bottom: 6px; }
.work-card__meta { font-size: 13px; color: var(--ink-500); margin-bottom: var(--sp-3); }

.work-card__hint {
    font-size: 12.5px;
    color: var(--ink-400);
    padding-top: var(--sp-3);
    border-top: 1px dashed var(--ink-200);
    line-height: 1.6;
}

/* 作品过程六要素 */
.process-list { display: grid; gap: var(--sp-3); counter-reset: process; }

.process-step {
    display: grid;
    grid-template-columns: 34px 1fr;
    gap: var(--sp-4);
    padding: var(--sp-4);
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-md);
}

.process-step__no {
    width: 34px; height: 34px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    background: var(--brand-red-soft);
    color: var(--brand-red-dark);
    font-weight: 800;
    font-size: 14px;
    border: 1px solid var(--brand-red-line);
}

.process-step__name { font-size: 15.5px; font-weight: 700; margin-bottom: 4px; }
.process-step__desc { font-size: 13px; color: var(--ink-500); margin-bottom: var(--sp-2); }
.process-step__content {
    font-size: 14.5px;
    color: var(--ink-700);
    line-height: 1.8;
    white-space: pre-line;
}
.process-step__content:empty::before {
    content: "该部分内容待补充。";
    color: var(--ink-300);
}

/* ==========================================================================
   文章正文
   ========================================================================== */

.prose { max-width: 72ch; margin: 0 auto; font-size: 16px; line-height: 1.9; color: var(--ink-700); }
.prose h2 { font-size: 24px; margin: var(--sp-6) 0 var(--sp-3); }
.prose h3 { font-size: 19px; margin: var(--sp-5) 0 var(--sp-2); }
.prose p { margin-bottom: var(--sp-4); }
.prose ul { margin: 0 0 var(--sp-4) var(--sp-4); list-style: disc; }
.prose ol { margin: 0 0 var(--sp-4) var(--sp-4); list-style: decimal; }
.prose li { margin-bottom: var(--sp-2); }
.prose blockquote {
    margin: var(--sp-5) 0;
    padding: var(--sp-4) var(--sp-5);
    border-left: 3px solid var(--brand-red);
    background: var(--brand-red-soft);
    border-radius: 0 var(--r-md) var(--r-md) 0;
    color: var(--ink-700);
    font-size: 16px;
}
.prose img { border-radius: var(--r-lg); margin: var(--sp-5) 0; }
.prose a { color: var(--brand-red); text-decoration: underline; text-underline-offset: 3px; }
.prose code {
    background: var(--ink-100);
    padding: 2px 6px;
    border-radius: var(--r-sm);
    font-size: .9em;
}
.prose pre {
    background: var(--ink-900);
    color: #E4E7EC;
    padding: var(--sp-4);
    border-radius: var(--r-md);
    overflow-x: auto;
    font-size: 14px;
}
.prose pre code { background: transparent; color: inherit; padding: 0; }
.prose table { width: 100%; border-collapse: collapse; margin-bottom: var(--sp-5); font-size: 15px; }
.prose th, .prose td { padding: 10px 14px; border: 1px solid var(--ink-200); text-align: left; }
.prose th { background: var(--ink-050); font-weight: 700; }

/* ==========================================================================
   页面头部
   ========================================================================== */

.page-head {
    background:
        radial-gradient(760px 340px at 84% -12%, var(--brand-red-soft) 0%, transparent 62%),
        var(--surface-alt);
    padding: clamp(36px, 6vw, 68px) 0;
    border-bottom: 1px solid var(--ink-100);
}

.page-head__title {
    font-size: clamp(26px, 4.4vw, 40px);
    margin-bottom: var(--sp-3);
}

.page-head__lead {
    font-size: 16px;
    color: var(--ink-600);
    max-width: 66ch;
    line-height: 1.85;
}

.breadcrumb {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 7px;
    font-size: 13px;
    color: var(--ink-400);
    margin-bottom: var(--sp-3);
}
.breadcrumb a { color: var(--ink-500); }
.breadcrumb a:hover { color: var(--brand-red); }
.breadcrumb__sep { color: var(--ink-300); }

/* ==========================================================================
   特色版块（真实世界 / 基地 / 作品馆 / 家长）
   ========================================================================== */

.feature {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--sp-6);
    align-items: center;
}

@media (min-width: 900px) {
    .feature { grid-template-columns: 1fr 1fr; gap: var(--sp-8); }
    .feature--reverse .feature__body { order: 2; }
}

.feature__quote {
    font-family: var(--font-serif);
    font-size: clamp(19px, 2.6vw, 25px);
    line-height: 1.65;
    color: var(--ink-900);
    padding-left: var(--sp-5);
    border-left: 3px solid var(--brand-red);
    margin: var(--sp-5) 0;
}

.feature__visual {
    border-radius: var(--r-xl);
    background: linear-gradient(150deg, #FAFBFC, #EEF1F5);
    border: 1px solid var(--ink-100);
    padding: var(--sp-6);
    min-height: 280px;
    display: grid;
    place-items: center;
    box-shadow: var(--shadow-sm);
}

/*
 * V3.2：德和堂板块改用宽幅实景图
 *
 * 删除原先只有「德」字的灰色占位框，
 * 改为家乡产业调研场景图，并标注 AI 场景示意。
 */
.feature__visual--bleed {
    position: relative;
    display: block;
    padding: 0;
    min-height: 320px;
    overflow: hidden;
    background: var(--ink-100);
}

.feature__visual-img {
    position: absolute;
    inset: 0;
    margin: 0;
    border-radius: 0;
    overflow: hidden;
}

.feature__visual-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center 42%;
    display: block;
}

.feature__visual-img figcaption {
    position: absolute;
    right: 12px;
    top: 12px;
    z-index: 3;
}

.feature__visual-note {
    position: relative;
    z-index: 2;
    margin: 0;
    padding: 16px 18px;
    font-size: 13px;
    line-height: 1.7;
    color: rgba(255, 255, 255, .92);
    background: linear-gradient(180deg, rgba(8, 11, 17, 0), rgba(8, 11, 17, .76));
}

.feature__visual-badge {
    display: inline-block;
    margin-left: 6px;
    padding: 1px 8px;
    font-size: 11px;
    border-radius: 999px;
    background: rgba(255, 255, 255, .16);
    border: 1px solid rgba(255, 255, 255, .3);
}

.feature__visual-inner {
    text-align: center;
    max-width: 320px;
}

.feature__visual-mark {
    width: 62px; height: 62px;
    margin: 0 auto var(--sp-4);
    border-radius: var(--r-lg);
    background: var(--brand-red);
    color: #fff;
    display: grid;
    place-items: center;
    font-size: 26px;
    font-weight: 800;
}

/* 步骤流程 */
.steps { counter-reset: step; display: grid; gap: var(--sp-3); }

.step {
    display: grid;
    grid-template-columns: 30px 1fr;
    gap: var(--sp-3);
    align-items: start;
}

.step__no {
    counter-increment: step;
    width: 30px; height: 30px;
    border-radius: 50%;
    border: 1.5px solid var(--brand-red-line);
    background: var(--brand-red-soft);
    color: var(--brand-red-dark);
    display: grid;
    place-items: center;
    font-size: 13px;
    font-weight: 700;
}

.step__no::before { content: counter(step); }

.step__text { font-size: 14.5px; color: var(--ink-700); line-height: 1.75; padding-top: 3px; }

/* ==========================================================================
   联系页
   ========================================================================== */

.contact-grid { display: grid; gap: var(--sp-5); grid-template-columns: 1fr; }
@media (min-width: 860px) { .contact-grid { grid-template-columns: 1.1fr .9fr; gap: var(--sp-7); } }

.info-row {
    display: flex;
    gap: var(--sp-4);
    padding: var(--sp-4) 0;
    border-bottom: 1px solid var(--ink-100);
}
.info-row:last-child { border-bottom: none; }

.info-row__label {
    font-size: 13px;
    color: var(--ink-400);
    flex-shrink: 0;
    width: 84px;
    padding-top: 2px;
}

.info-row__value { font-size: 15px; color: var(--ink-800); line-height: 1.7; }

/* ==========================================================================
   页脚
   ========================================================================== */

.site-footer {
    background: var(--ink-900);
    color: var(--ink-300);
    padding: var(--sp-8) 0 var(--sp-5);
    margin-top: auto;
}

.site-footer a { color: var(--ink-300); }
.site-footer a:hover { color: #fff; }

.site-footer__top {
    display: grid;
    gap: var(--sp-6);
    grid-template-columns: 1fr;
    padding-bottom: var(--sp-6);
    border-bottom: 1px solid rgba(255, 255, 255, .1);
}

@media (min-width: 860px) {
    .site-footer__top { grid-template-columns: 1.4fr 1fr 1fr; gap: var(--sp-7); }
}

.site-footer .brand__name { color: #fff; }
.site-footer .brand__tag { color: var(--ink-400); }

.site-footer__slogan {
    font-family: var(--font-serif);
    font-size: 17px;
    color: #fff;
    margin-top: var(--sp-4);
    line-height: 1.7;
}

.site-footer__title {
    font-size: 13px;
    font-weight: 700;
    letter-spacing: .1em;
    color: #fff;
    margin-bottom: var(--sp-4);
    text-transform: uppercase;
}

.site-footer__links { display: flex; flex-direction: column; gap: 10px; font-size: 14.5px; }

.site-footer__bottom {
    padding-top: var(--sp-5);
    display: flex;
    flex-wrap: wrap;
    gap: var(--sp-3);
    justify-content: space-between;
    align-items: center;
    font-size: 13px;
    color: var(--ink-400);
}

.site-footer__legal { display: flex; flex-wrap: wrap; gap: var(--sp-4); }

/* ==========================================================================
   通用：空状态 / 分页 / 提示条
   ========================================================================== */

.empty-state {
    text-align: center;
    padding: var(--sp-8) var(--sp-5);
    border: 1px dashed var(--ink-200);
    border-radius: var(--r-lg);
    background: var(--surface-alt);
}

.empty-state__title { font-size: 17px; margin-bottom: var(--sp-2); }
.empty-state__text { font-size: 14px; color: var(--ink-500); max-width: 46ch; margin: 0 auto; line-height: 1.8; }

.pagination { display: flex; flex-wrap: wrap; gap: 6px; justify-content: center; margin-top: var(--sp-6); }

.pagination a, .pagination span {
    min-width: 38px; height: 38px;
    padding: 0 12px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--r-md);
    border: 1px solid var(--ink-200);
    font-size: 14px;
    color: var(--ink-700);
}

.pagination a:hover { border-color: var(--brand-red); color: var(--brand-red); }
.pagination .is-current { background: var(--brand-red); border-color: var(--brand-red); color: #fff; font-weight: 600; }
.pagination .is-disabled { opacity: .45; }

.flash {
    padding: var(--sp-3) var(--sp-4);
    border-radius: var(--r-md);
    font-size: 14px;
    margin-bottom: var(--sp-4);
    border: 1px solid;
}
.flash--success { background: var(--ok-soft); border-color: #BFE5D5; color: #14664A; }
.flash--error { background: var(--danger-soft); border-color: #F2C9CF; color: #8E2437; }
.flash--warning { background: var(--warn-soft); border-color: #F0DCB4; color: #7A5310; }
.flash--info { background: var(--info-soft); border-color: #C9DDF5; color: #1B4C86; }

/* ==========================================================================
   动画
   ========================================================================== */

@keyframes fadeUp {
    from { opacity: 0; transform: translateY(14px); }
    to { opacity: 1; transform: translateY(0); }
}

.animate-in { animation: fadeUp .55s cubic-bezier(.22, .61, .36, 1) both; }
.animate-in--d1 { animation-delay: .06s; }
.animate-in--d2 { animation-delay: .12s; }
.animate-in--d3 { animation-delay: .18s; }
.animate-in--d4 { animation-delay: .24s; }
.animate-in--d5 { animation-delay: .3s; }

/* ==========================================================================
   打印
   ========================================================================== */

@media print {
    .site-header, .site-footer, .nav-toggle { display: none !important; }
    body { color: #000; }
}

/* ==========================================================================
   V2.0 改版新增组件
   --------------------------------------------------------------------------
   四大板块卡 / 级别小卡 / 导航下拉 / 四大特色卡
   ========================================================================== */

/* ---------------- 四大板块卡 ---------------- */

.track-card {
    position: relative;
    display: flex;
    flex-direction: column;
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-lg);
    overflow: hidden;
    transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
}

.track-card:hover {
    border-color: var(--brand-red-line);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.track-card::before {
    content: "";
    position: absolute;
    left: 0; top: 0; bottom: 0;
    width: 4px;
    background: var(--brand-red);
}

.track-card--amber::before { background: #C8862B; }
.track-card--teal::before { background: #1E8A7A; }
.track-card--indigo::before { background: #4A5BA8; }

/*
 * 板块封面（V3.2：四张卡片统一 3:2，图片在上、文字在下）
 *
 * 固定比例 + object-fit: cover，
 * 保证人物不被横向压缩或拉伸；焦点位置由场景配置的 focus 决定。
 */
.track-card__cover {
    position: relative;
    margin: 0;
    border-radius: var(--r-md) var(--r-md) 0 0;
    overflow: hidden;
    background: var(--ink-050);
    aspect-ratio: 3 / 2;
}

.track-card__cover .scene-image,
.track-card__cover > figure,
.track-card__cover img {
    width: 100%;
    height: 100%;
    margin: 0;
}

.track-card__cover > figure {
    display: block;
    position: relative;
}

.track-card__cover img {
    object-fit: cover;
    object-position: center 28%;
    display: block;
}

.track-card__cover figcaption {
    position: absolute;
    left: 12px;
    bottom: 12px;
    z-index: 2;
}

/* 无场景图时的中文标识（正式中文标识，不使用英文占位符） */
.track-card__cover-mark {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    font-family: var(--font-serif);
    font-size: 46px;
    color: var(--brand-red);
    opacity: .72;
    background: linear-gradient(135deg, var(--ink-050), var(--ink-100));
}

@media (max-width: 767px) {
    .track-card__cover { aspect-ratio: 16 / 9; }
    .track-card__cover-mark { font-size: 38px; }
}

.track-card__head {
    padding: var(--sp-5) var(--sp-5) 0;
}

.track-card__key {
    display: inline-block;
    font-size: 11.5px;
    font-weight: 700;
    letter-spacing: .1em;
    text-transform: uppercase;
    color: var(--brand-red);
    background: var(--brand-red-soft);
    border: 1px solid var(--brand-red-line);
    padding: 3px 9px;
    border-radius: var(--r-sm);
    margin-bottom: 10px;
}

.track-card--amber .track-card__key { color: #8A5A12; background: #FBF1E0; border-color: #EBD9B8; }
.track-card--teal .track-card__key { color: #14655A; background: #E4F4F1; border-color: #BFE2DC; }
.track-card--indigo .track-card__key { color: #37417A; background: #EAECF7; border-color: #CDD2EC; }

.track-card__key--inline { margin-bottom: 12px; }

.track-card__title {
    font-size: 21px;
    margin-bottom: 4px;
}

.track-card__body {
    padding: var(--sp-4) var(--sp-5) var(--sp-5);
    display: flex;
    flex-direction: column;
    flex: 1;
}

.track-card__lead {
    font-size: 15px;
    color: var(--ink-700);
    line-height: 1.85;
    margin-bottom: 12px;
}

.track-card__desc {
    font-size: 14px;
    color: var(--ink-500);
    line-height: 1.8;
    margin-bottom: var(--sp-4);
}

.track-card__foot {
    margin-top: auto;
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    align-items: center;
}

/* ---------------- 级别小卡 ---------------- */

.level-mini {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding: var(--sp-5);
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-lg);
    transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
}

.level-mini:hover {
    border-color: var(--brand-red-line);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.level-mini__code {
    font-size: 12px;
    font-weight: 800;
    letter-spacing: .08em;
    color: #fff;
    background: var(--brand-red);
    padding: 3px 10px;
    border-radius: var(--r-sm);
    align-self: flex-start;
}

.level-mini__name {
    font-size: 18px;
    font-weight: 700;
    color: var(--ink-900);
}

.level-mini__desc {
    font-size: 13.5px;
    color: var(--ink-600);
    line-height: 1.75;
}

/* ---------------- 四大特色卡 ---------------- */

.feature-card {
    padding: var(--sp-5);
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-lg);
    position: relative;
    overflow: hidden;
    transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
}

.feature-card:hover {
    border-color: var(--brand-red-line);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.feature-card__no {
    font-size: 12px;
    font-weight: 800;
    letter-spacing: .1em;
    color: var(--brand-red);
    margin-bottom: 10px;
}

.feature-card__name {
    font-size: 19px;
    margin-bottom: 8px;
}

.feature-card__desc {
    font-size: 14.5px;
    color: var(--ink-600);
    line-height: 1.8;
}

/* ---------------- 导航下拉 ---------------- */

.site-nav__item { position: relative; }

.site-nav__toggle {
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.site-nav__toggle::after {
    content: "";
    width: 5px; height: 5px;
    border-right: 1.5px solid currentColor;
    border-bottom: 1.5px solid currentColor;
    transform: rotate(45deg) translateY(-2px);
    transition: transform .2s ease;
}

.site-nav__item:hover .site-nav__toggle::after,
.site-nav__item:focus-within .site-nav__toggle::after {
    transform: rotate(225deg) translateY(-2px);
}

.site-nav__dropdown {
    position: absolute;
    top: calc(100% + 10px);
    left: 0;
    min-width: 240px;
    background: var(--surface);
    border: 1px solid var(--ink-100);
    border-radius: var(--r-lg);
    box-shadow: var(--shadow-lg);
    padding: 8px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-6px);
    transition: opacity .18s ease, transform .18s ease, visibility .18s;
}

.site-nav__item:hover .site-nav__dropdown,
.site-nav__item:focus-within .site-nav__dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.site-nav__dropdown a {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 9px 12px;
    border-radius: var(--r-md);
    font-size: 14px;
    color: var(--ink-700);
    line-height: 1.5;
}

/* 下拉中的中文序号标记（V3.0：不显示英文占位符） */
.site-nav__dropdown-no {
    flex-shrink: 0;
    min-width: 26px;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: .06em;
    color: var(--brand-red);
    opacity: .75;
}

.site-nav__dropdown a:hover { background: var(--ink-050); color: var(--brand-red); }

@media (max-width: 1023px) {
    .site-nav__dropdown {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        border: none;
        padding: 0 0 8px 12px;
        display: none;
    }

    .site-nav__item.is-open .site-nav__dropdown { display: block; }
    .site-nav__toggle::after { display: none; }
}

/* ---------------- 响应式：课程页两栏 ---------------- */

@media (min-width: 1024px) {
    .course-layout { grid-template-columns: 1fr 320px !important; }
}

/* ==========================================================================
   场景图组件（首页 Banner / 板块头图 / 课程头图）
   -------------------------------------------------------------------------- */

.scene-image {
    position: relative;
    margin: 0;
    border-radius: var(--r-lg);
    overflow: hidden;
    background: var(--ink-100);
    border: 1px solid var(--ink-100);
}

.scene-image img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* AI 生成素材角标：明确标示为示意，避免被误认为真实课堂照片 */
.ai-badge {
    position: absolute;
    right: 10px;
    bottom: 10px;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 11px;
    font-weight: 600;
    line-height: 1.4;
    color: var(--ink-700);
    background: rgba(255, 255, 255, .93);
    border: 1px solid var(--ink-200);
    border-radius: var(--r-sm);
    padding: 3px 9px;
    box-shadow: 0 1px 4px rgba(20, 24, 31, .08);
}

.ai-badge::before {
    content: "";
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--brand-red);
    flex-shrink: 0;
}

/* ---------------- 首页首屏 Banner ---------------- */

.hero__cover {
    position: relative;
    margin: 0 0 14px;
    border-radius: var(--r-lg);
    overflow: hidden;
    /* 16:9 起步，大屏按视口高度自适应，避免图片被过度裁切 */
    aspect-ratio: 16 / 9;
    background: var(--ink-100);
    border: 1px solid var(--ink-100);
    box-shadow: var(--shadow-md);
}

@media (min-width: 1024px) {
    .hero__cover {
        /* 首屏可视高度 = 视口高 − 导航与上下留白 */
        aspect-ratio: auto;
        height: clamp(420px, calc(100svh - 260px), 720px);
    }
}

@media (min-width: 1600px) {
    .hero__cover { height: clamp(480px, calc(100svh - 240px), 780px); }
}

.hero__cover img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

.hero__cover::after {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, rgba(20, 24, 31, 0) 55%, rgba(20, 24, 31, .18) 100%);
    pointer-events: none;
}

/* ---------------- 板块头图 ---------------- */

.track-hero {
    position: relative;
    margin: 0 0 28px;
    border-radius: var(--r-lg);
    overflow: hidden;
    aspect-ratio: 3 / 1;
    background: var(--ink-100);
    border: 1px solid var(--ink-100);
}

.track-hero img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

@media (max-width: 767px) {
    .track-hero { aspect-ratio: 16 / 9; }
}

/* ---------------- 页面头图（作品馆 / 德和堂） ---------------- */

.page-hero {
    position: relative;
    margin: 0 0 32px;
    border-radius: var(--r-lg);
    overflow: hidden;
    aspect-ratio: 21 / 9;
    background: var(--ink-100);
    border: 1px solid var(--ink-100);
}

.page-hero img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

@media (max-width: 767px) {
    .page-hero { aspect-ratio: 16 / 9; }
}