/* ============================================================
   NTH Station 品牌站专用样式 v5.0
   设计宪法：竞技装备实验室质感（对标 Arc'teryx / Peak Performance / Apple）
   配色：snow 雪白系 + black 深灰黑系 + accent 深青绿主点缀 + 竞技红 CTA
   v5.0 核心强化：厚重感（巨字震撼 + 黑底章节 + 厚 hairline）
                 + 实力感（数据墙巨字 + 认证徽标阵列 + 章节大编号锚点）
   ============================================================ */

:root {
    /* ---------- 三色系统（v5.0 切换） ---------- */
    /* black 深灰黑系（更深更克制） */
    --nth-black-950: #0a0a0a;
    --nth-black-900: #1a1a1a;
    --nth-black-800: #2c2c2c;
    --nth-black-700: #3d3d3d;
    --nth-black-500: #777777;
    --nth-black-300: #b5b5b0;

    /* snow 雪白系（带一丝暖意） */
    --nth-snow-50:  #faf9f5;
    --nth-snow-100: #f5f4ee;
    --nth-snow-200: #ebeae3;
    --nth-snow-300: #d6d5cd;
    --nth-snow-400: #a8a8a0;

    /* accent 深青绿（主点缀色：数据线、装饰线、状态色） */
    --nth-accent:        #1e3a40;
    --nth-accent-light:  #2d5158;
    --nth-accent-bright: #4a7a82;
    --nth-accent-dark:   #15272c;

    /* 竞技红（仅 CTA 按钮，不参与装饰） */
    --nth-red:        #C8102E;
    --nth-red-dark:   #a00d24;

    /* ---------- 兼容旧变量名（避免破坏现有 HTML） ---------- */
    --nth-white:     var(--nth-snow-50);
    --nth-blue-gray: var(--nth-snow-100);
    --nth-deep-gray: var(--nth-black-900);
    --nth-aux-gray:  var(--nth-black-500);

    /* ---------- 字体 ---------- */
    --nth-font-title: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    --nth-font-body:  'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;

    /* ---------- 间距与圆角（v5.0 厚重感） ---------- */
    --nth-section-py:    160px;   /* 模块上下间距 80→160 */
    --nth-section-py-sm: 96px;
    --nth-card-radius:   8px;     /* 卡片圆角 12→8（工业感） */
    --nth-card-pad:      32px;    /* 卡片内边距 24→32 */
    --nth-btn-radius:    4px;     /* 按钮圆角 8→4 */

    --nth-shadow:        0 1px 2px rgba(0,0,0,0.04), 0 4px 16px rgba(0,0,0,0.04);
    --nth-shadow-hover:  0 2px 4px rgba(0,0,0,0.06), 0 12px 32px rgba(0,0,0,0.08);
    --nth-shadow-deep:   0 8px 32px rgba(0,0,0,0.12), 0 24px 64px rgba(0,0,0,0.16);

    --nth-transition:    200ms cubic-bezier(0.2, 0, 0, 1);
    --nth-container:     1280px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body.nth-station {
    margin: 0;
    padding: 0;
    font-family: var(--nth-font-body);
    color: var(--nth-black-900);
    background: var(--nth-snow-50);
    font-size: 16px;
    line-height: 1.6;
    font-weight: 400;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* 极轻微冰晶背景纹理（仅 snow 章节可见） */
body.nth-station {
    background-image:
        radial-gradient(circle at 12% 18%, rgba(30, 58, 64, 0.025) 0%, transparent 35%),
        radial-gradient(circle at 88% 82%, rgba(30, 58, 64, 0.025) 0%, transparent 35%);
    background-attachment: fixed;
}

/* ============================================================
   字体层级（v5.0 巨字震撼系统）
   ============================================================ */

/* Display 巨字（开篇/收尾/数据墙，字重 800 强化厚重感） */
.nth-display {
    font-family: var(--nth-font-title);
    font-weight: 800;
    line-height: 0.95;
    letter-spacing: -0.04em;
    margin: 0;
}
.nth-display--1 { font-size: clamp(72px, 12vw, 180px); }
.nth-display--2 { font-size: clamp(56px, 8vw, 120px); }
.nth-display--3 { font-size: clamp(40px, 5vw, 80px); }

.nth-h1 {
    font-size: clamp(40px, 5vw, 72px);
    font-weight: 700;
    line-height: 1.05;
    letter-spacing: -0.03em;
    margin: 0;
}

.nth-h2 {
    font-size: clamp(28px, 3vw, 44px);
    font-weight: 600;
    line-height: 1.15;
    letter-spacing: -0.02em;
    margin: 0;
}

.nth-h3 {
    font-size: 22px;
    font-weight: 600;
    line-height: 1.3;
    margin: 0;
}

/* 标签：全大写 + 强 tracking（v5.0 强化） */
.nth-label {
    font-size: 12px;
    font-weight: 600;
    color: var(--nth-accent);
    letter-spacing: 0.22em;
    text-transform: uppercase;
    line-height: 1;
    margin: 0;
}

.nth-label--snow { color: var(--nth-accent-bright); }
.nth-label--red  { color: var(--nth-red); }

.nth-aux {
    color: var(--nth-black-500);
    font-size: 17px;
    line-height: 1.65;
    max-width: 720px;
}

/* 数据巨字 */
.nth-stat-num {
    font-family: var(--nth-font-title);
    font-weight: 700;
    font-size: clamp(72px, 9vw, 140px);
    line-height: 0.9;
    letter-spacing: -0.04em;
    color: var(--nth-accent);
    margin: 0;
}

.nth-stat-num--red { color: var(--nth-red); }
.nth-stat-num--snow { color: var(--nth-snow-50); }

/* ============================================================
   容器与 Section
   ============================================================ */
.nth-container {
    max-width: var(--nth-container);
    margin: 0 auto;
    padding: 0 32px;
}

.nth-section {
    padding: var(--nth-section-py) 0;
    position: relative;
}

.nth-section--snow {
    background: var(--nth-snow-50);
}

.nth-section--gray {
    background: var(--nth-snow-100);
}

/* v5.0 黑底章节：电影感 + 厚重感 */
.nth-section--dark {
    background: var(--nth-black-950);
    color: var(--nth-snow-50);
}

.nth-section--dark .nth-h1,
.nth-section--dark .nth-h2,
.nth-section--dark .nth-h3 { color: var(--nth-snow-50); }

.nth-section--dark .nth-aux { color: var(--nth-snow-400); }

.nth-section--dark .nth-label { color: var(--nth-accent-bright); }

/* 章节大编号（左上半透明巨字锚点） */
.nth-section-index {
    position: absolute;
    top: 56px;
    right: 32px;
    font-family: var(--nth-font-title);
    font-weight: 700;
    font-size: clamp(120px, 14vw, 220px);
    line-height: 1;
    color: var(--nth-black-900);
    opacity: 0.06;
    pointer-events: none;
    user-select: none;
    letter-spacing: -0.05em;
    z-index: 0;
}

.nth-section--dark .nth-section-index { color: var(--nth-snow-50); opacity: 0.08; }

/* 章节头：标签 + 标题 + 副标 + 装饰线（统一容器） */
.nth-section-head {
    margin-bottom: 96px;
    position: relative;
    z-index: 1;
}

.nth-section-head__label {
    display: inline-flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 28px;
}

.nth-section-head__label::before {
    content: '';
    display: inline-block;
    width: 48px;
    height: 2px;
    background: var(--nth-accent);
}

.nth-section--dark .nth-section-head__label::before { background: var(--nth-accent-bright); }

.nth-section-head__aux {
    margin-top: 32px;
}

/* 章节分隔线（粗 hairline，accent 深青绿） */
.nth-divider {
    height: 3px;
    background: var(--nth-accent);
    border: none;
    margin: 0;
}

.nth-divider--hairline {
    height: 1px;
    background: rgba(0, 0, 0, 0.08);
}

.nth-section--dark .nth-divider--hairline { background: rgba(255, 255, 255, 0.08); }

/* ============================================================
   按钮（v5.0 圆角降至 4px）
   ============================================================ */
.nth-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 16px 32px;
    font-family: var(--nth-font-body);
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    border-radius: var(--nth-btn-radius);
    border: 1px solid var(--nth-black-900);
    background: var(--nth-black-900);
    color: var(--nth-snow-50);
    cursor: pointer;
    text-decoration: none;
    transition: transform var(--nth-transition), background var(--nth-transition),
                color var(--nth-transition), border-color var(--nth-transition);
}

.nth-btn:hover {
    transform: translateY(-2px);
    background: var(--nth-red);
    border-color: var(--nth-red);
}

.nth-btn--ghost {
    background: transparent;
    color: var(--nth-snow-50);
    border-color: rgba(245, 244, 238, 0.5);
}

.nth-btn--ghost:hover {
    background: var(--nth-snow-50);
    color: var(--nth-black-950);
    border-color: var(--nth-snow-50);
}

.nth-btn--dark-ghost {
    background: transparent;
    color: var(--nth-black-900);
    border-color: var(--nth-black-900);
}

.nth-btn--dark-ghost:hover {
    background: var(--nth-black-900);
    color: var(--nth-snow-50);
    border-color: var(--nth-black-900);
}

.nth-btn--red {
    background: var(--nth-red);
    border-color: var(--nth-red);
    color: var(--nth-snow-50);
}

.nth-btn--red:hover {
    background: var(--nth-red-dark);
    border-color: var(--nth-red-dark);
}

/* ============================================================
   顶部导航
   ============================================================ */
.nth-navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: 22px 0;
    transition: background var(--nth-transition), padding var(--nth-transition),
                backdrop-filter var(--nth-transition);
}

.nth-navbar--scrolled {
    background: rgba(250, 249, 245, 0.94);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.06);
    padding: 14px 0;
}

.nth-navbar__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nth-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--nth-snow-50);
    text-decoration: none;
    font-weight: 700;
    font-size: 17px;
    letter-spacing: 0.02em;
    transition: color var(--nth-transition);
}

.nth-navbar--scrolled .nth-brand { color: var(--nth-black-900); }

.nth-brand-logo {
    height: 32px;
    width: auto;
    display: block;
    transition: filter var(--nth-transition);
}

/* 首屏深色背景态：黑色 logo 反白显示；scrolled 浅底态保持原黑 */
.nth-navbar:not(.nth-navbar--scrolled) .nth-brand-logo {
    filter: brightness(0) invert(1);
}

.nth-nav-links {
    display: flex;
    gap: 36px;
    align-items: center;
}

.nth-nav-links a {
    color: rgba(245, 244, 238, 0.85);
    text-decoration: none;
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    transition: color var(--nth-transition);
    position: relative;
}

.nth-nav-links a::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -8px;
    width: 0;
    height: 1px;
    background: currentColor;
    transition: width var(--nth-transition);
}

.nth-nav-links a:hover::after { width: 100%; }
.nth-nav-links a:hover { color: var(--nth-snow-50); }

.nth-navbar--scrolled .nth-nav-links a,
.nth-navbar--scrolled .nth-nav-links a:hover {
    color: var(--nth-black-900);
}

/* ============================================================
   屏 1 · 首屏 Hero（视频背景 + 双标签浮层 + 巨字标题）
   ============================================================ */
.nth-hero {
    position: relative;
    width: 100%;
    height: 100vh;
    min-height: 640px;
    overflow: hidden;
    background: var(--nth-black-950);
}

.nth-hero__video {
    position: absolute;
    top: 0; left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: 1;
}

.nth-hero__overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg,
                rgba(10, 10, 10, 0.55) 0%,
                rgba(10, 10, 10, 0.25) 35%,
                rgba(10, 10, 10, 0.5) 70%,
                rgba(10, 10, 10, 0.85) 100%);
    z-index: 2;
}

/* ============================================================
   视频声音开关 UI（sound_on 控制）
   - .nth-sound-toggle：角落小切换按钮（默认静音自动播放，可开/关）
   - .nth-sound-toggle--hero：品牌片醒目中央大圆按钮（点一下开声并隐藏）
   浏览器策略：所有 video 保持 autoplay muted loop；sound_on 仅控制 UI 形态
   ============================================================ */
.nth-sound-toggle {
    position: absolute;
    right: 14px;
    bottom: 14px;
    z-index: 5;
    width: 38px;
    height: 38px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: rgba(10, 10, 10, 0.45);
    border: 1px solid rgba(245, 244, 238, 0.5);
    color: var(--nth-snow-50);
    cursor: pointer;
    padding: 0;
    transition: background 150ms ease, transform 150ms ease;
    backdrop-filter: blur(4px);
}
.nth-sound-toggle:hover {
    background: rgba(10, 10, 10, 0.7);
    transform: translateY(-2px);
}
.nth-sound-toggle svg {
    width: 18px;
    height: 18px;
}

/* 品牌片醒目版：中央大圆形 + 半透明底 + 文字引导 */
.nth-sound-toggle--hero {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 6;
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    gap: 14px;
    background: rgba(10, 10, 10, 0.55);
    border: 1px solid rgba(245, 244, 238, 0.6);
    color: var(--nth-snow-50);
    cursor: pointer;
    padding: 28px 36px;
    border-radius: 999px;
    width: auto;
    height: auto;
    backdrop-filter: blur(6px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.45);
    transition: background 150ms ease, transform 150ms ease;
}
.nth-sound-toggle--hero:hover {
    background: rgba(10, 10, 10, 0.72);
    transform: translate(-50%, calc(-50% - 4px));
}
.nth-sound-toggle--hero .nth-sound-toggle__icon {
    width: 44px;
    height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: var(--nth-accent);
}
.nth-sound-toggle--hero .nth-sound-toggle__icon svg {
    width: 22px;
    height: 22px;
}
.nth-sound-toggle--hero .nth-sound-toggle__text {
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    white-space: nowrap;
}

.nth-hero__content {
    position: relative;
    z-index: 3;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: 0 0 120px 0;
    color: var(--nth-snow-50);
}

.nth-hero__top-tags {
    position: absolute;
    top: 120px;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    padding: 0 32px;
    max-width: var(--nth-container);
    margin: 0 auto;
    z-index: 4;
}

/* v5.0 标签：深青绿描边（替代红色描边，更克制高级） */
.nth-top-tag {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 18px;
    border-radius: 999px;
    background: rgba(10, 10, 10, 0.5);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(74, 122, 130, 0.55);
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--nth-snow-50);
    text-decoration: none;
    transition: all var(--nth-transition);
}

.nth-top-tag:hover {
    background: var(--nth-accent);
    border-color: var(--nth-accent-light);
}

/* v5.0 hero 标题：display-2 巨字（字重 800 强化厚重感） */
.nth-hero__heading {
    font-family: var(--nth-font-title);
    font-size: clamp(56px, 9vw, 140px);
    font-weight: 800;
    line-height: 0.95;
    letter-spacing: -0.04em;
    margin: 0 0 28px 0;
}

.nth-hero__subheading {
    font-size: clamp(20px, 1.6vw, 26px);
    font-weight: 400;
    line-height: 1.4;
    color: rgba(245, 244, 238, 0.88);
    max-width: 760px;
    margin: 0 0 56px 0;
    letter-spacing: 0.01em;
}

.nth-hero__cta-row {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

/* hero 滚动指示器（小细节强化"在读长片"感） */
.nth-hero__scroll-hint {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 4;
    color: rgba(245, 244, 238, 0.5);
    font-size: 10px;
    letter-spacing: 0.3em;
    text-transform: uppercase;
    text-align: center;
}

.nth-hero__scroll-hint::after {
    content: '';
    display: block;
    width: 1px;
    height: 32px;
    background: rgba(245, 244, 238, 0.4);
    margin: 12px auto 0;
}

/* ============================================================
   屏 1.5 · 品牌主题片嵌入（v5.0 新增）
   ============================================================ */
.nth-brand-film {
    background: var(--nth-black-950);
    color: var(--nth-snow-50);
    padding: var(--nth-section-py) 0;
    position: relative;
}

.nth-brand-film__head {
    text-align: center;
    margin-bottom: 64px;
}

.nth-brand-film__label {
    display: inline-flex;
    align-items: center;
    gap: 16px;
    color: var(--nth-accent-bright);
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.3em;
    text-transform: uppercase;
    margin-bottom: 24px;
}

.nth-brand-film__label::before,
.nth-brand-film__label::after {
    content: '';
    width: 32px;
    height: 1px;
    background: var(--nth-accent-bright);
}

.nth-brand-film__title {
    font-family: var(--nth-font-title);
    font-size: clamp(36px, 4.5vw, 64px);
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.1;
    color: var(--nth-snow-50);
    margin: 0;
}

.nth-brand-film__video-wrap {
    position: relative;
    max-width: 1280px;
    margin: 0 auto;
    aspect-ratio: 16 / 9;
    background: var(--nth-black-900);
    border: 1px solid rgba(74, 122, 130, 0.2);
    overflow: hidden;
    cursor: pointer;
}

.nth-brand-film__video-wrap video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.nth-brand-film__play {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(10, 10, 10, 0.35);
    transition: opacity var(--nth-transition);
}

.nth-brand-film__play-btn {
    width: 96px;
    height: 96px;
    border-radius: 50%;
    background: var(--nth-snow-50);
    color: var(--nth-black-950);
    display: flex;
    align-items: center;
    justify-content: center;
    border: none;
    cursor: pointer;
    transition: transform var(--nth-transition);
}

.nth-brand-film__video-wrap:hover .nth-brand-film__play-btn {
    transform: scale(1.08);
}

/* ============================================================
   屏 2 · 百年瓦萨（时间轴 + 视频 + 图文混排）
   ============================================================ */
.nth-timeline {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.nth-timeline__list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.nth-timeline__item {
    display: grid;
    grid-template-columns: 120px 1fr;
    gap: 32px;
    padding: 32px 0;
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

.nth-timeline__item:last-child { border-bottom: none; }

.nth-timeline__year {
    font-family: var(--nth-font-title);
    font-size: 40px;
    font-weight: 700;
    color: var(--nth-accent);  /* v5.0 红→accent */
    letter-spacing: -0.02em;
    line-height: 1;
}

.nth-timeline__title {
    font-size: 20px;
    font-weight: 600;
    margin: 0 0 8px 0;
    color: var(--nth-black-900);
}

.nth-timeline__desc {
    font-size: 15px;
    color: var(--nth-black-500);
    line-height: 1.65;
    margin: 0;
}

.nth-video-frame {
    position: relative;
    width: 100%;
    aspect-ratio: 16 / 9;
    background: var(--nth-black-900);
    border-radius: var(--nth-card-radius);
    overflow: hidden;
    box-shadow: var(--nth-shadow-deep);
}

.nth-video-frame video {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* 瓦萨图文混排补充图（v5.0 新增） */
.nth-wasa-gallery {
    display: grid;
    grid-template-columns: 2fr 1fr;
    grid-template-rows: 1fr 1fr;
    gap: 16px;
    margin-top: 64px;
    aspect-ratio: 16 / 9;
}

.nth-wasa-gallery__item {
    background: var(--nth-snow-200);
    border-radius: var(--nth-card-radius);
    overflow: hidden;
    position: relative;
    min-height: 0;
    min-width: 0;
}

/* 大图占左列满高（产品图主角），右侧 2 小图竖排撑满 */
.nth-wasa-gallery__item:first-child {
    grid-row: 1 / span 2;
}

.nth-wasa-gallery__item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 600ms ease;
}

.nth-wasa-gallery__item:hover img { transform: scale(1.04); }

/* ============================================================
   屏 3 · 长春队（数据墙 + team 视频 + 冠军墙 + 氛围图）
   v5.0 黑底章节，强化电影感
   ============================================================ */
.nth-team-bg-video {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.32;
    z-index: 0;
}

.nth-team-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg,
                rgba(10, 10, 10, 0.6) 0%,
                rgba(10, 10, 10, 0.85) 100%);
    z-index: 1;
}

.nth-team-content {
    position: relative;
    z-index: 2;
}

/* v5.0 巨字数据墙（黑底反白） */
.nth-stat-wall {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 48px;
    margin: 0 0 96px 0;
}

.nth-stat-wall--dark { color: var(--nth-snow-50); }

.nth-stat {
    text-align: left;
    padding-right: 24px;
    border-right: 1px solid rgba(255, 255, 255, 0.1);
}

.nth-stat:last-child { border-right: none; }

.nth-stat-wall:not(.nth-stat-wall--dark) .nth-stat {
    border-right-color: rgba(0, 0, 0, 0.08);
}

.nth-stat__num {
    font-family: var(--nth-font-title);
    font-size: clamp(72px, 9vw, 140px);
    font-weight: 700;
    color: var(--nth-accent);
    line-height: 0.9;
    letter-spacing: -0.04em;
    margin: 0 0 16px 0;
}

.nth-stat-wall--dark .nth-stat__num { color: var(--nth-accent-bright); }
.nth-stat__num--red { color: var(--nth-red); }
.nth-stat-wall--dark .nth-stat__num--red { color: var(--nth-red); }

.nth-stat__label {
    font-size: 13px;
    color: var(--nth-black-500);
    font-weight: 500;
    line-height: 1.5;
    letter-spacing: 0.04em;
}

.nth-stat-wall--dark .nth-stat__label { color: var(--nth-snow-400); }

.nth-stat__sub {
    font-size: 11px;
    color: var(--nth-accent);
    font-weight: 600;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    margin-top: 8px;
}

.nth-stat-wall--dark .nth-stat__sub { color: var(--nth-accent-bright); }

.nth-champion-wall {
    padding: 48px;
    background: rgba(245, 244, 238, 0.04);
    border-radius: var(--nth-card-radius);
    border: 1px solid rgba(74, 122, 130, 0.25);
    backdrop-filter: blur(8px);
}

.nth-champion-wall__title {
    font-size: 12px;
    font-weight: 600;
    color: var(--nth-accent-bright);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    margin: 0 0 24px 0;
}

.nth-champion-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px 48px;
    margin: 0;
    padding: 0;
    list-style: none;
}

.nth-champion-list li {
    font-size: 17px;
    font-weight: 600;
    color: var(--nth-snow-50);
    padding: 12px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.nth-champion-list li .role {
    display: block;
    color: var(--nth-snow-400);
    font-weight: 400;
    font-size: 13px;
    margin-top: 4px;
    letter-spacing: 0.04em;
}

.nth-disclaimer {
    margin-top: 32px;
    padding: 20px 24px;
    background: rgba(200, 16, 46, 0.08);
    border-left: 3px solid var(--nth-red);
    font-size: 13px;
    color: var(--nth-snow-400);
    line-height: 1.7;
}

/* 队伍氛围全景图（黑底章节里的小条带） */
.nth-panorama-strip {
    margin: 64px 0;
    width: 100%;
    height: 240px;
    overflow: hidden;
    border-radius: var(--nth-card-radius);
    position: relative;
}

.nth-panorama-strip img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.7;
}

/* ============================================================
   屏 4 · 万达（全宽视频背景，深青绿渐变遮罩）
   ============================================================ */
.nth-fullvideo {
    position: relative;
    width: 100%;
    height: 90vh;
    min-height: 600px;
    overflow: hidden;
}

.nth-fullvideo__video {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* v5.0 渐变遮罩从黑色 → accent 深青绿（呼应新配色） */
.nth-fullvideo__overlay {
    position: absolute;
    inset: 0;
    background:
        linear-gradient(90deg,
            rgba(10, 10, 10, 0.85) 0%,
            rgba(21, 39, 44, 0.55) 50%,
            rgba(10, 10, 10, 0.3) 100%);
    z-index: 2;
}

.nth-fullvideo__content {
    position: relative;
    z-index: 3;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    color: var(--nth-snow-50);
    max-width: 760px;
}

/* ============================================================
   屏 5 · 4 款战袍（项目卡 + 背景视频/图）
   ============================================================ */
.nth-projects-grid {
    display: grid;
    gap: 128px;
}

.nth-project-card {
    display: grid;
    grid-template-columns: 1.05fr 1fr;
    gap: 80px;
    align-items: center;
}

.nth-project-card:nth-child(even) .nth-project__media {
    order: 2;
}

/* v5.0 项目媒体：支持背景视频 */
.nth-project__media {
    position: relative;
    aspect-ratio: 4 / 5;
    background: var(--nth-black-900);
    border-radius: var(--nth-card-radius);
    overflow: hidden;
    box-shadow: var(--nth-shadow-deep);
}

.nth-project__media img,
.nth-project__media video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 600ms ease;
}

.nth-project__media:hover img,
.nth-project__media:hover video { transform: scale(1.03); }

/* 媒体左上角的项目编号浮层（v5.0 增加层次感） */
.nth-project__media-tag {
    position: absolute;
    top: 20px;
    left: 20px;
    z-index: 2;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 14px;
    background: rgba(10, 10, 10, 0.7);
    backdrop-filter: blur(8px);
    color: var(--nth-snow-50);
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    border-radius: 999px;
}

.nth-project__tag {
    display: inline-block;
    padding: 6px 14px;
    background: var(--nth-accent);
    color: var(--nth-snow-50);
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    border-radius: var(--nth-btn-radius);
    margin-bottom: 24px;
}

.nth-project__name {
    font-family: var(--nth-font-title);
    font-size: clamp(32px, 3.6vw, 52px);
    font-weight: 700;
    color: var(--nth-black-900);
    line-height: 1.1;
    margin: 0 0 12px 0;
    letter-spacing: -0.03em;
}

.nth-project__subtitle {
    font-size: 14px;
    color: var(--nth-black-500);
    margin: 0 0 32px 0;
    font-weight: 500;
    letter-spacing: 0.04em;
}

.nth-project__features {
    list-style: none;
    padding: 0;
    margin: 0 0 40px 0;
}

.nth-project__features li {
    padding: 14px 0;
    font-size: 15px;
    color: var(--nth-black-900);
    line-height: 1.6;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    position: relative;
    padding-left: 28px;
}

.nth-project__features li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 22px;
    width: 14px;
    height: 2px;
    background: var(--nth-accent);  /* v5.0 红→accent */
}

/* v5.0 工艺表格：去除卡片阴影，改 hairline 分割（apple.com 风格） */
.nth-craft-table {
    width: 100%;
    border-collapse: collapse;
    margin: 0 0 40px 0;
    border-top: 2px solid var(--nth-black-900);
}

.nth-craft-table th,
.nth-craft-table td {
    text-align: left;
    padding: 18px 0;
    font-size: 14px;
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
    vertical-align: top;
}

.nth-craft-table th {
    width: 120px;
    color: var(--nth-black-500);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.14em;
    font-size: 11px;
    padding-top: 22px;
}

.nth-craft-table td {
    color: var(--nth-black-900);
    line-height: 1.5;
    font-weight: 500;
}

.nth-craft-table td .solves {
    display: block;
    color: var(--nth-accent);  /* v5.0 红→accent */
    font-size: 13px;
    margin-top: 6px;
    font-weight: 500;
}

/* ============================================================
   屏 6 · 极致工艺（核心重做）
   v5.0：顶部 craft-film 视频 + 6 步工匠流程 + 数据墙
   ============================================================ */
.nth-craft-film-wrap {
    position: relative;
    width: 100%;
    aspect-ratio: 21 / 9;
    background: var(--nth-black-950);
    border-radius: var(--nth-card-radius);
    overflow: hidden;
    margin-bottom: 128px;
    box-shadow: var(--nth-shadow-deep);
}

.nth-craft-film-wrap video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* 风洞试验 · 左右图文（屏 6 内嵌，1440×1440 视频贴右）
   替代原全宽黑底方案：方形视频不适合黑边留白，改用 5:7 图文并排 */
.nth-wind-tunnel-pair {
    display: grid;
    grid-template-columns: 5fr 7fr;
    gap: 80px;
    align-items: center;
    margin-top: 96px;
}

.nth-wind-tunnel-pair__title {
    margin: 16px 0 12px 0;
}

.nth-wind-tunnel-pair__desc {
    margin: 0;
    max-width: none;
}

.nth-wind-tunnel-pair__stats {
    list-style: none;
    margin: 40px 0 0 0;
    padding: 32px 0 0 0;
    border-top: 1px solid rgba(0, 0, 0, 0.08);
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.nth-wind-tunnel-pair__stats li {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.nth-wind-tunnel-pair__stats .num {
    font-family: var(--nth-font-title);
    font-size: 40px;
    font-weight: 700;
    line-height: 1;
    color: var(--nth-black-950);
    letter-spacing: -0.02em;
}

.nth-wind-tunnel-pair__stats .unit {
    font-size: 13px;
    font-weight: 600;
    color: var(--nth-accent);
    letter-spacing: 0.06em;
}

.nth-wind-tunnel-pair__stats .lbl {
    font-size: 11px;
    font-weight: 600;
    color: var(--nth-black-500);
    letter-spacing: 0.22em;
    text-transform: uppercase;
    margin-top: 6px;
}

.nth-wind-tunnel-pair__video {
    position: relative;
    aspect-ratio: 16 / 9;
    background: var(--nth-black-950);
    overflow: hidden;
    border-radius: var(--nth-card-radius);
    box-shadow: var(--nth-shadow-deep);
}

.nth-wind-tunnel-pair__video video {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

@media (max-width: 768px) {
    .nth-wind-tunnel-pair {
        grid-template-columns: 1fr;
        gap: 32px;
        margin-top: 64px;
    }
    .nth-wind-tunnel-pair__stats {
        margin-top: 24px;
        padding-top: 24px;
    }
    .nth-wind-tunnel-pair__stats .num {
        font-size: 28px;
    }
}

/* v5.0 6 步工匠流程 */
.nth-craft-steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1px;
    background: rgba(0, 0, 0, 0.08);
    border-top: 2px solid var(--nth-black-900);
    border-bottom: 2px solid var(--nth-black-900);
    margin-bottom: 128px;
}

.nth-craft-step {
    background: var(--nth-snow-50);
    padding: 56px 36px;
    display: flex;
    flex-direction: column;
    gap: 18px;
    position: relative;
    transition: background var(--nth-transition);
}

.nth-craft-step:hover { background: var(--nth-snow-100); }

.nth-craft-step__num {
    font-family: var(--nth-font-title);
    font-size: 28px;
    font-weight: 800;
    color: var(--nth-accent);
    letter-spacing: 0.1em;
    line-height: 1;
}

.nth-craft-step__title-cn {
    font-family: var(--nth-font-title);
    font-size: 36px;
    font-weight: 800;
    color: var(--nth-black-900);
    letter-spacing: -0.02em;
    line-height: 1.1;
    margin: 0;
}

.nth-craft-step__title-en {
    font-size: 11px;
    font-weight: 700;
    color: var(--nth-accent);
    letter-spacing: 0.22em;
    text-transform: uppercase;
    margin: 0;
}

/* v5.0 mcp 反馈强化：数据浮层字号 14→22px，加粗，accent 强对比 */
.nth-craft-step__data {
    font-family: var(--nth-font-title);
    font-size: 22px;
    color: var(--nth-black-950);
    font-weight: 700;
    line-height: 1.35;
    padding: 20px 0 0 0;
    border-top: 2px solid var(--nth-accent);
    margin: 4px 0 0 0;
    letter-spacing: -0.01em;
}

.nth-craft-step__desc {
    font-size: 14px;
    color: var(--nth-black-500);
    line-height: 1.65;
    margin: 0;
}

/* v5.0 工艺特写图墙（4 张并列） */
.nth-craft-details {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    margin-bottom: 128px;
}

.nth-craft-details__item {
    aspect-ratio: 3 / 4;
    background: var(--nth-black-900);
    border-radius: var(--nth-card-radius);
    overflow: hidden;
    position: relative;
}

.nth-craft-details__item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 600ms ease;
}

.nth-craft-details__item:hover img { transform: scale(1.05); }

.nth-craft-details__caption {
    position: absolute;
    bottom: 16px;
    left: 16px;
    right: 16px;
    color: var(--nth-snow-50);
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    z-index: 2;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.8);
}

/* v5.0 技术数据墙（替代原 6 个数据卡） */
.nth-tech-wall {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0;
    border-top: 2px solid var(--nth-black-900);
    border-bottom: 2px solid var(--nth-black-900);
}

.nth-tech-cell {
    padding: 56px 40px;
    border-right: 1px solid rgba(0, 0, 0, 0.08);
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
    background: var(--nth-snow-50);
}

nth-tech-cell:nth-child(3n) { border-right: none; }
.nth-tech-cell:nth-last-child(-n+3) { border-bottom: none; }

.nth-tech-cell__num {
    font-family: var(--nth-font-title);
    font-size: clamp(56px, 6vw, 96px);
    font-weight: 700;
    color: var(--nth-accent);
    line-height: 0.9;
    letter-spacing: -0.03em;
    margin: 0 0 16px 0;
}

.nth-tech-cell__num .unit {
    font-size: 18px;
    color: var(--nth-black-500);
    font-weight: 500;
    margin-left: 8px;
    letter-spacing: 0;
}

.nth-tech-cell__label {
    font-size: 11px;
    font-weight: 600;
    color: var(--nth-accent);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    margin: 0 0 12px 0;
}

.nth-tech-cell__desc {
    font-size: 13px;
    color: var(--nth-black-500);
    line-height: 1.65;
    margin: 0;
}

/* ============================================================
   屏 7 · 媒体见证 + 认证徽标阵列（v5.0 强化）
   ============================================================ */
.nth-media-wall {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
}

.nth-media-card {
    display: block;
    padding: 48px 40px;
    background: var(--nth-snow-50);
    border: 1px solid rgba(0, 0, 0, 0.08);
    border-radius: var(--nth-card-radius);
    text-decoration: none;
    color: inherit;
    transition: all var(--nth-transition);
    position: relative;
    overflow: hidden;
}

.nth-media-card::before {
    content: '';
    position: absolute;
    left: 0; top: 0;
    width: 4px;
    height: 100%;
    background: var(--nth-accent);
    transform: scaleY(0);
    transform-origin: top;
    transition: transform var(--nth-transition);
}

.nth-media-card:hover::before { transform: scaleY(1); }

.nth-media-card:hover {
    background: var(--nth-snow-100);
    transform: translateY(-2px);
}

.nth-media-card__channel {
    font-size: 12px;
    font-weight: 700;
    color: var(--nth-accent);  /* v5.0 红→accent */
    letter-spacing: 0.18em;
    text-transform: uppercase;
    margin: 0 0 6px 0;
}

.nth-media-card__date {
    font-size: 13px;
    color: var(--nth-black-500);
    margin: 0 0 28px 0;
    font-weight: 500;
}

.nth-media-card__title {
    font-family: var(--nth-font-title);
    font-size: 24px;
    font-weight: 600;
    color: var(--nth-black-900);
    line-height: 1.3;
    margin: 0 0 16px 0;
    letter-spacing: -0.01em;
}

.nth-media-card__desc {
    font-size: 14px;
    color: var(--nth-black-500);
    line-height: 1.7;
    margin: 0 0 28px 0;
}

.nth-media-card__cta {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 12px;
    font-weight: 600;
    color: var(--nth-black-900);
    letter-spacing: 0.14em;
    text-transform: uppercase;
    border-bottom: 2px solid var(--nth-black-900);
    padding-bottom: 4px;
}

.nth-media-disclaimer {
    margin-top: 48px;
    text-align: center;
    font-size: 13px;
    color: var(--nth-black-500);
    line-height: 1.8;
}

/* v5.0 认证徽标阵列（实力感核心） */
.nth-cert-wall {
    margin-top: 96px;
    padding: 64px 48px;
    background: var(--nth-black-950);
    border-radius: var(--nth-card-radius);
    color: var(--nth-snow-50);
    text-align: center;
}

.nth-cert-wall__title {
    font-size: 12px;
    font-weight: 600;
    color: var(--nth-accent-bright);
    letter-spacing: 0.3em;
    text-transform: uppercase;
    margin: 0 0 16px 0;
}

.nth-cert-wall__sub {
    font-family: var(--nth-font-title);
    font-size: 32px;
    font-weight: 700;
    color: var(--nth-snow-50);
    letter-spacing: -0.02em;
    margin: 0 0 48px 0;
}

.nth-cert-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    max-width: 960px;
    margin: 0 auto;
}

.nth-cert-item {
    padding: 32px 16px;
    background: rgba(245, 244, 238, 0.04);
    border: 1px solid rgba(74, 122, 130, 0.25);
    border-radius: var(--nth-btn-radius);
}

.nth-cert-item__badge {
    font-family: var(--nth-font-title);
    font-size: 28px;
    font-weight: 700;
    color: var(--nth-snow-50);
    letter-spacing: -0.02em;
    line-height: 1;
    margin: 0 0 12px 0;
}

.nth-cert-item__label {
    font-size: 11px;
    font-weight: 600;
    color: var(--nth-accent-bright);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    margin: 0;
}

.nth-awards-strip {
    margin-top: 48px;
    padding: 32px;
    background: var(--nth-snow-50);
    border-radius: var(--nth-card-radius);
    border: 1px solid rgba(0, 0, 0, 0.06);
    display: flex;
    align-items: center;
    gap: 32px;
}

.nth-awards-strip__img {
    flex: 0 0 320px;
    height: 120px;
    border-radius: var(--nth-btn-radius);
    overflow: hidden;
}

.nth-awards-strip__img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.nth-awards-strip__text {
    flex: 1;
}

.nth-awards-strip__title {
    font-family: var(--nth-font-title);
    font-size: 22px;
    font-weight: 600;
    color: var(--nth-black-900);
    margin: 0 0 8px 0;
}

.nth-awards-strip__desc {
    font-size: 14px;
    color: var(--nth-black-500);
    line-height: 1.65;
    margin: 0;
}

/* ============================================================
   屏 8 · 关于
   ============================================================ */
.nth-about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.nth-timeline-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.nth-timeline-list li {
    display: grid;
    grid-template-columns: 96px 1fr;
    gap: 24px;
    padding: 20px 0;
    border-bottom: 1px solid rgba(0, 0, 0, 0.06);
    font-size: 15px;
}

.nth-timeline-list li:last-child { border-bottom: none; }

.nth-timeline-list .year {
    font-family: var(--nth-font-title);
    font-weight: 700;
    color: var(--nth-accent);  /* v5.0 红→accent */
    letter-spacing: -0.01em;
}

/* ============================================================
   页脚
   ============================================================ */
.nth-footer {
    background: var(--nth-black-950);
    color: rgba(245, 244, 238, 0.65);
    padding: 96px 0 32px 0;
    font-size: 14px;
    border-top: 4px solid var(--nth-accent);
}

.nth-footer__row {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 64px;
}

.nth-footer__brand {
    color: var(--nth-snow-50);
    font-family: var(--nth-font-title);
    font-size: 28px;
    font-weight: 700;
    margin: 0 0 12px 0;
    letter-spacing: -0.01em;
}

.nth-footer__slogan {
    color: var(--nth-accent-bright);
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.2em;
    text-transform: uppercase;
}

.nth-footer__col-title {
    color: var(--nth-snow-50);
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    margin: 0 0 16px 0;
}

.nth-footer__col a,
.nth-footer__col p {
    color: rgba(245, 244, 238, 0.65);
    text-decoration: none;
    font-size: 14px;
    line-height: 1.8;
    margin: 0;
    transition: color var(--nth-transition);
}

.nth-footer__col a:hover { color: var(--nth-snow-50); }

.nth-footer__copyright {
    border-top: 1px solid rgba(245, 244, 238, 0.08);
    padding-top: 32px;
    text-align: center;
    font-size: 12px;
    color: rgba(245, 244, 238, 0.4);
    letter-spacing: 0.04em;
}
/* 备案号（固定法律信息，不走 CMS config，防后台误改丢合规） */
.nth-footer__beian {
    margin-top: 12px;
    text-align: center;
    font-size: 12px;
    color: rgba(245, 244, 238, 0.5);
    letter-spacing: 0.04em;
}
.nth-footer__beian a { color: inherit; text-decoration: none; transition: color .15s ease; }
.nth-footer__beian a:hover { color: rgba(245, 244, 238, 0.9); }
.nth-footer__beian-sep { margin: 0 8px; opacity: 0.6; }

/* ============================================================
   左侧固定 section index（v5.0 新增，强化"在读长片"感）
   ============================================================ */
.nth-side-index {
    position: fixed;
    left: 32px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 50;
    display: flex;
    flex-direction: column;
    gap: 16px;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--nth-transition);
}

.nth-side-index--visible {
    opacity: 1;
    pointer-events: auto;
}

.nth-side-index__item {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--nth-black-500);
    text-decoration: none;
    font-size: 10px;
    font-weight: 600;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    transition: color var(--nth-transition);
}

.nth-side-index__dot {
    width: 24px;
    height: 1px;
    background: currentColor;
    transition: width var(--nth-transition);
}

.nth-side-index__item:hover,
.nth-side-index__item--active {
    color: var(--nth-black-900);
}

.nth-side-index__item--active .nth-side-index__dot { width: 48px; }

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1100px) {
    .nth-side-index { display: none; }
}

@media (max-width: 960px) {
    :root {
        --nth-section-py: 96px;
    }
    .nth-container { padding: 0 24px; }
    .nth-hero__top-tags {
        flex-direction: column;
        gap: 8px;
        top: 96px;
        align-items: flex-start;
    }
    .nth-timeline,
    .nth-project-card,
    .nth-about-grid,
    .nth-team-content .nth-stat-wall {
        grid-template-columns: 1fr;
        gap: 48px;
    }
    .nth-stat-wall { grid-template-columns: repeat(2, 1fr); gap: 32px; }
    .nth-stat { border-right: none; padding-right: 0; }
    .nth-tech-wall { grid-template-columns: 1fr; }
    .nth-tech-cell { border-right: none; }
    .nth-craft-steps { grid-template-columns: 1fr; }
    .nth-craft-details { grid-template-columns: repeat(2, 1fr); }
    .nth-media-wall { grid-template-columns: 1fr; }
    .nth-cert-grid { grid-template-columns: repeat(2, 1fr); }
    .nth-wasa-gallery { grid-template-columns: 1fr; grid-template-rows: auto; aspect-ratio: auto; }
    .nth-wasa-gallery__item { aspect-ratio: 4 / 3; }
    .nth-wasa-gallery__item:first-child { grid-row: auto; }
    .nth-awards-strip { flex-direction: column; }
    .nth-awards-strip__img { flex: 0 0 auto; width: 100%; }
    .nth-project-card:nth-child(even) .nth-project__media { order: 0; }
    .nth-footer__row { grid-template-columns: 1fr; gap: 32px; }
    .nth-champion-list { grid-template-columns: 1fr; }
    .nth-champion-wall { padding: 32px 24px; }
    .nth-section-index { font-size: clamp(80px, 18vw, 140px); top: 32px; right: 16px; }
}

/* PC 默认隐藏汉堡 + 抽屉（仅移动端显示） */
.nth-menu-toggle { display: none; }
.nth-drawer, .nth-drawer-overlay { display: none; }

@media (max-width: 640px) {
    .nth-nav-links { display: none; }
    .nth-brand span { display: none; }
    .nth-section-head { margin-bottom: 56px; }

    /* 汉堡按钮 */
    .nth-menu-toggle {
        display: flex; flex-direction: column; justify-content: center; gap: 5px;
        width: 40px; height: 40px; background: none; border: none; cursor: pointer;
        padding: 0; margin-left: auto;
    }
    .nth-menu-toggle span { display: block; width: 24px; height: 2px; background: #0a0a0a; }

    /* 抽屉（从右侧滑出） */
    .nth-drawer {
        display: block; position: fixed; top: 0; right: -280px; width: 280px; height: 100vh;
        background: #faf9f5; z-index: 2000; transition: right 0.3s ease; padding: 72px 24px 24px;
        overflow-y: auto; box-shadow: -4px 0 24px rgba(0,0,0,0.1);
    }
    .nth-drawer.open { right: 0; }
    .nth-drawer__nav a {
        display: block; padding: 16px 0; border-bottom: 1px solid rgba(0,0,0,0.08);
        color: #0a0a0a; text-decoration: none; font-size: 16px;
    }
    .nth-drawer__close {
        position: absolute; top: 16px; right: 20px; background: none; border: none;
        font-size: 28px; cursor: pointer; color: #0a0a0a; line-height: 1;
    }
    .nth-drawer-overlay {
        display: block; opacity: 0; pointer-events: none; position: fixed; inset: 0;
        background: rgba(0,0,0,0.4); z-index: 1999; transition: opacity 0.3s;
    }
    .nth-drawer-overlay.open { opacity: 1; pointer-events: auto; }

    /* P1 细节：巨字 / 大编号 / 数据墙 / 工艺表 移动端适配 */
    .nth-display--1 { font-size: clamp(48px, 14vw, 96px); }
    .nth-section-index { font-size: clamp(60px, 14vw, 100px); }
    .nth-stat-wall { grid-template-columns: 1fr; }
    .nth-craft-table { overflow-x: auto; display: block; }
}