/* ============================================================
   BOLIDE — v5 全面重写
   设计语言：近黑底 / 大留白 / 巨型衬线标题 / 黑白灰为主
   蓝色仅用于：关键数字、hover、极少量强调
   去除了：全屏网格、X 分隔符、DOC/FIG 编号堆砌、坐标小字
   ============================================================ */

/* ---------- 字体 ---------- */
@font-face {
  font-family: 'Bugatti Display';
  src: url('../fonts/bugatti-display-400.woff2') format('woff2');
  font-weight: 400; font-style: normal; font-display: swap;
}
@font-face {
  font-family: 'Bugatti Mono';
  src: url('../fonts/bugatti-mono-400.woff2') format('woff2');
  font-weight: 400; font-style: normal; font-display: swap;
}
@font-face {
  font-family: 'Bugatti Text';
  src: url('../fonts/bugatti-text-400.woff2') format('woff2');
  font-weight: 400; font-style: normal; font-display: swap;
}
@font-face {
  font-family: 'Bugatti Text';
  src: url('../fonts/bugatti-text-700.woff2') format('woff2');
  font-weight: 700; font-style: normal; font-display: swap;
}

/* ---------- 变量 ---------- */
:root {
  --bg:        #050507;
  --bg-soft:   #0a0b0f;
  --panel:     #12141c;
  --ink:       #f2f2f5;
  --ink-dim:   #a9a9b3;
  --ink-faint: #7d7d88;
  --accent:    #004bfa;          /* 布加迪蓝，同 tourbillon */
  --line:      rgba(255, 255, 255, 0.12);
  --line-soft: rgba(255, 255, 255, 0.07);
  --font-display: 'BUGATTI Display', 'Noto Serif SC', 'Songti SC', 'STSong', serif;
  --font-text:    'BUGATTI Text', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono:    'BUGATTI Mono', 'Consolas', 'Courier New', monospace;
  --w-doc: 1280px;
  --w-prose: 660px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

/* ---------- 基础 ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-text);
  font-size: 18px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}
::selection { background: var(--accent); color: #fff; }
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; }

/* 段落文字宽度约束 */
.prose { max-width: var(--w-prose); }

/* ---------- 导航（tourbillon 同款） ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 22px 24px;
  transition: background 0.5s, padding 0.5s, backdrop-filter 0.5s;
}
.nav.is-solid {
  background: rgba(5, 5, 7, 0.82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  padding: 14px 24px;
  border-bottom: 1px solid var(--line);
}
.nav__inner { display: flex; align-items: center; justify-content: space-between; }
.nav__brand { display: flex; align-items: baseline; gap: 12px; color: #fff; }
.nav__brand svg { height: 18px; width: auto; }
.nav__brand-sub {
  font-family: var(--font-display);
  font-size: 15px;
  letter-spacing: 0.34em;
  color: var(--ink-dim);
}
.nav__now {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  letter-spacing: 0.22em;
  color: var(--ink-dim);
  padding: 8px 14px;
  border: 1px solid var(--line);
  background: rgba(10, 11, 15, 0.6);
  border-radius: 0;
  transition: color 0.3s, border-color 0.3s;
}
.nav__now::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 8px rgba(0, 75, 250, 0.8);
}
.nav__now b { color: var(--ink); font-weight: 400; }
.nav__lang {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  transition: opacity 0.6s var(--ease);
}
.nav__lang.is-hidden { opacity: 0; pointer-events: none; }
.lang-btn {
  padding: 8px 6px;
  border: none;
  background: none;
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--ink-dim);
  position: relative;
  transition: color 0.3s;
  cursor: pointer;
}
.lang-btn::after {
  content: '';
  position: absolute;
  left: 6px; right: 6px; bottom: 4px;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transition: transform 0.3s var(--ease);
}
.lang-btn:hover { color: var(--ink); }
.lang-btn:hover::after { transform: scaleX(1); }
.nav__menu-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  letter-spacing: 0.24em;
  color: var(--ink);
  padding: 8px 14px;
  border: 1px solid var(--line);
  background: rgba(10, 11, 15, 0.6);
  border-radius: 0;
  cursor: pointer;
  transition: border-color 0.3s;
  font-family: var(--font-mono);
}
.nav__menu-btn:hover { border-color: var(--accent); }
.nav__menu-btn.is-hidden { opacity: 0; pointer-events: none; }
.nav__menu-icon { position: relative; width: 16px; height: 10px; }
.nav__menu-icon i {
  position: absolute;
  left: 0;
  width: 16px;
  height: 1px;
  background: currentColor;
  transition: transform 0.35s var(--ease);
}
.nav__menu-icon i:first-child { top: 0; }
.nav__menu-icon i:last-child { bottom: 0; }
.nav__menu-btn[aria-expanded="true"] i:first-child { transform: translateY(4.5px) rotate(45deg); }
.nav__menu-btn[aria-expanded="true"] i:nth-child(2) { opacity: 0; }
.nav__menu-btn[aria-expanded="true"] i:last-child { transform: translateY(-4.5px) rotate(-45deg); }
.nav__progress {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 2px;
  background: transparent;
}
.nav__progress i {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--accent), #3f7bff);
  box-shadow: 0 0 10px rgba(0, 75, 250, 0.6);
  transition: width 0.2s linear;
}
.is-hidden { opacity: 0; pointer-events: none; }

/* ---------- 章节菜单浮层（tourbillon 同款） ---------- */
.menu-overlay {
  position: fixed;
  inset: 0;
  z-index: 89;
  background: rgba(5, 5, 7, 0.97);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  display: none;
  place-items: center;
  opacity: 0;
  transition: opacity 0.4s var(--ease);
}
.menu-overlay.is-open {
  display: grid;
  opacity: 1;
}
.menu-overlay__nav {
  display: grid;
  grid-template-columns: repeat(2, minmax(140px, 220px));
  gap: 6px 40px;
  padding: 24px;
}
.menu-overlay__nav a {
  display: flex;
  gap: 12px;
  padding: 14px 10px;
  font-family: var(--font-display);
  font-size: 22px;
  letter-spacing: 0.1em;
  color: var(--ink);
  border-bottom: 1px solid var(--line);
  transition: color 0.3s, border-color 0.3s, padding-left 0.3s;
}
.menu-overlay__nav a:hover { color: #6f9dff; border-color: var(--accent); padding-left: 16px; }
.menu-overlay__nav a .idx { font-family: var(--font-mono); font-size: 12px; color: var(--ink-faint); align-self: center; }

/* ---------- 滚动进度表盘（tourbillon 同款） ---------- */
.scroll-gauge {
  position: fixed;
  right: 26px;
  bottom: 26px;
  width: 44px; height: 44px;
  z-index: 90;
  opacity: 0;
  transition: opacity 0.5s;
}
.scroll-gauge.is-on { opacity: 1; }
.scroll-gauge svg { width: 100%; height: 100%; transform: rotate(-90deg); }
.scroll-gauge circle { fill: none; stroke-width: 2; }
.scroll-gauge .sg__bar {
  stroke: var(--accent);
  stroke-linecap: round;
  stroke-dasharray: 119.4;
  stroke-dashoffset: 119.4;
}
.sg__num {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-size: 10px;
  color: var(--ink-dim);
}

/* 移动端 nav */
@media (max-width: 720px) {
  .nav__now { display: none; }
  .nav { padding: 14px 16px; }
  .nav.is-solid { padding: 10px 16px; }
  .nav__brand svg { height: 15px; }
  .nav__brand-sub { font-size: 13px; }
  .nav__menu-btn { padding: 7px 10px; }
  .scroll-gauge { right: 16px; bottom: 16px; width: 38px; height: 38px; }
  .menu-overlay__nav { grid-template-columns: 1fr; gap: 2px; }
  .menu-overlay__nav a { font-size: 19px; }
}

/* ---------- HERO ---------- */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex; flex-direction: column; justify-content: flex-end;
  overflow: hidden;
}
.hero__media { position: absolute; inset: 0; }
.hero__media video, .hero__media img { width: 100%; height: 100%; object-fit: cover; }
.hero__veil {
  position: absolute; inset: 0;
  background:
    linear-gradient(to bottom, rgba(11,11,13,.5) 0%, rgba(11,11,13,.06) 38%, rgba(11,11,13,.96) 100%),
    linear-gradient(to right, rgba(11,11,13,.5), transparent 60%);
}
.hero__content {
  position: relative;
  padding: 0 clamp(1.5rem, 5vw, 4rem) clamp(2.6rem, 7vh, 4.6rem);
  max-width: var(--w-doc);
  margin: 0 auto;
  width: 100%;
}
.hero__tag {
  font-family: var(--font-mono); font-size: .82rem;
  letter-spacing: .42em; text-transform: uppercase;
  color: var(--ink-dim);
  margin-bottom: 1.6rem;
}
.hero__title {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(5rem, 21vw, 17rem);
  line-height: .88;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--ink);
}
.hero__sub {
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  color: var(--ink-dim);
  margin-top: 1.4rem;
  max-width: 34em;
}
.hero__data {
  display: flex; gap: clamp(2rem, 6vw, 5.5rem);
  margin-top: clamp(2rem, 5vh, 3.2rem);
  padding-top: 1.6rem;
  border-top: 1px solid var(--line);
}
.hero__data > div { display: flex; flex-direction: column; gap: .15rem; }
.hero__data b {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4vw, 2.9rem);
  font-weight: 400; line-height: 1;
  letter-spacing: .02em;
}
.hero__data b em { font-style: normal; color: var(--accent); }
.hero__data span {
  font-family: var(--font-mono); font-size: .78rem;
  letter-spacing: .3em; color: var(--ink-faint);
  text-transform: uppercase;
}

/* 滚动提示 */
.hero__scroll {
  position: absolute; bottom: 2rem; left: 50%; transform: translateX(-50%);
  font-family: var(--font-mono); font-size: .72rem;
  letter-spacing: .5em; color: var(--ink-faint);
  display: flex; flex-direction: column; align-items: center; gap: .7rem;
}
.hero__scroll::after {
  content: ''; width: 1px; height: 3.4rem;
  background: linear-gradient(to bottom, var(--ink-faint), transparent);
  animation: scrollPulse 2.4s var(--ease) infinite;
}
@keyframes scrollPulse {
  0% { transform: scaleY(0); transform-origin: top; }
  45% { transform: scaleY(1); transform-origin: top; }
  55% { transform: scaleY(1); transform-origin: bottom; }
  100% { transform: scaleY(0); transform-origin: bottom; }
}

/* ---------- 通用章节 ---------- */
.chapter { padding: clamp(6rem, 13vh, 10rem) 0; position: relative; }
.chapter--dark { background: var(--bg-soft); }
.chapter__inner {
  max-width: var(--w-doc);
  margin: 0 auto;
  padding: 0 clamp(1.5rem, 5vw, 4rem);
}

/* 章节标题：大号衬线 + 小标签，无编号堆砌 */
.ch-head { margin-bottom: clamp(2.8rem, 7vh, 5rem); }
.ch-head__tag {
  display: flex; align-items: center; gap: 1.1rem;
  font-family: var(--font-mono); font-size: .82rem;
  letter-spacing: .4em; text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 1.4rem;
}
.ch-head__tag::before { content: ''; width: 3rem; height: 1px; background: var(--line); }
.ch-head h2 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(2.6rem, 6.4vw, 4.8rem);
  line-height: 1.05;
  letter-spacing: .03em;
}
.ch-head h2 .latin {
  display: block;
  font-family: var(--font-mono);
  font-size: .3em;
  letter-spacing: .5em;
  color: var(--ink-faint);
  margin-top: 1.1rem;
  text-transform: uppercase;
}
.ch-head--center { text-align: center; }
.ch-head--center .ch-head__tag { justify-content: center; }
.ch-head--center .ch-head__tag::after { content: ''; width: 3rem; height: 1px; background: var(--line); }

/* ---------- 引言（全屏引文区） ---------- */
.mantra {
  min-height: 72vh;
  display: flex; align-items: center; justify-content: center;
  text-align: center;
  padding: 8rem clamp(1.5rem, 5vw, 4rem);
}
.mantra blockquote {
  max-width: 22em;
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4.6vw, 3.4rem);
  line-height: 1.35;
  letter-spacing: .02em;
}
.mantra blockquote .zh {
  display: block;
  font-family: var(--font-text);
  font-size: .46em;
  color: var(--ink-dim);
  line-height: 1.9;
  margin-top: 2.2rem;
  letter-spacing: .04em;
}
.mantra--en blockquote .zh { margin-top: 0; }

/* ---------- 正文与布局 ---------- */
.lead {
  font-size: clamp(1.25rem, 2.4vw, 1.55rem);
  line-height: 1.75;
  color: var(--ink);
  letter-spacing: .01em;
}
.prose p { margin-bottom: 1.4em; }
.prose p b { color: var(--ink); font-weight: 700; }

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(3rem, 7vw, 7rem);
  align-items: start;
}
.split > .prose:last-child { padding-top: clamp(2rem, 5vw, 4rem); }

/* ---------- 图片 ---------- */
.figure { margin: clamp(3rem, 8vh, 6rem) 0; }
.figure--full { margin-left: calc(50% - 50vw); margin-right: calc(50% - 50vw); }
.figure--full .figure__media img { width: 100%; }
.figure__media { overflow: hidden; background: #0e0e11; }
.figure__media img { width: 100%; transition: transform 1.4s var(--ease); }
.figure__media:hover img { transform: scale(1.02); }
.figure__cap {
  display: flex; align-items: baseline; gap: 1rem;
  margin-top: 1rem;
  font-size: 1rem; line-height: 1.7;
  color: var(--ink-faint);
}
.figure__cap .en { color: var(--ink-dim); }
.figure__cap .zh { color: var(--ink-faint); }
.figure__cap .no {
  font-family: var(--font-mono); font-size: .78rem;
  letter-spacing: .3em; color: var(--accent);
  flex-shrink: 0;
}

/* 双图并排 */
.figrow { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(1.5rem, 3vw, 2.5rem); margin: clamp(3rem, 8vh, 6rem) 0; }
.figrow .figure { margin: 0; }

/* ---------- 巨型数字区 ---------- */
.bignums {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: clamp(1.5rem, 3vw, 3rem);
  margin: clamp(3.5rem, 8vh, 6rem) 0;
}
.bignums > div {
  padding: clamp(1.6rem, 3vw, 2.4rem) 0 0;
  border-top: 1px solid var(--line);
}
.bignums b {
  display: block;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(2.6rem, 5.4vw, 4.4rem);
  line-height: 1.05;
  letter-spacing: .01em;
}
.bignums b em { font-style: normal; color: var(--accent); }
.bignums span {
  display: block;
  font-family: var(--font-mono); font-size: .82rem;
  letter-spacing: .3em; color: var(--ink-faint);
  text-transform: uppercase;
  margin-top: .8rem;
}
.bignums small { font-size: .4em; color: var(--ink-faint); letter-spacing: .05em; margin-left: .25em; }

/* ---------- 草图画廊 ---------- */
.gallery {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(1rem, 2vw, 1.8rem);
  margin: clamp(3.5rem, 8vh, 6rem) 0;
}
.gallery figure { margin: 0; position: relative; }
.gallery img { width: 100%; aspect-ratio: 16/10; object-fit: cover; filter: grayscale(.12); transition: transform 1.2s var(--ease), filter .6s; }
.gallery figure:hover img { transform: scale(1.03); filter: grayscale(0); }
.gallery figcaption {
  margin-top: .9rem;
  font-size: .84rem; color: var(--ink-dim);
  display: flex; flex-direction: column; gap: .2rem;
}
.gallery figcaption span { font-family: var(--font-mono); font-size: .62rem; letter-spacing: .3em; color: var(--ink-faint); text-transform: uppercase; }

/* ---------- 性能动画条 ---------- */
.perf { margin: clamp(3.5rem, 8vh, 6rem) 0; }
.perf__group + .perf__group { margin-top: clamp(3rem, 6vh, 4.5rem); }
.perf__group h3 {
  font-family: var(--font-mono); font-size: .95rem;
  font-weight: 400; letter-spacing: .38em;
  color: var(--ink-dim); text-transform: uppercase;
  margin-bottom: 1.6rem;
}
.perf__bar { margin-bottom: 1.9rem; }
.perf__bar-top { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: .55rem; }
.perf__bar-top .lbl { font-size: 1.05rem; color: var(--ink-dim); }
.perf__bar-top .val {
  font-family: var(--font-display);
  font-size: 1.9rem; color: var(--ink);
  letter-spacing: .02em;
}
.perf__bar-top .val small {
  font-family: var(--font-mono); font-size: .55em;
  color: var(--ink-faint); margin-left: .5em; letter-spacing: .15em;
}
.perf__track {
  position: relative; height: 2px;
  background: var(--line-soft);
}
.perf__fill {
  position: absolute; left: 0; top: 0; bottom: 0;
  width: 0;
  background: linear-gradient(to right, var(--ink-faint), var(--ink));
  transition: width 1.6s var(--ease);
}
.perf__bar.is-run .perf__fill { width: var(--w); }
.perf__mark {
  position: absolute; top: -3px;
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--accent);
  opacity: 0; transform: scale(0);
  transition: opacity .4s, transform .4s var(--ease);
}
.perf__bar.is-run .perf__mark { opacity: 1; transform: scale(1); transition-delay: 1.4s; }
.perf__scale { display: flex; justify-content: space-between; margin-top: .5rem; font-family: var(--font-mono); font-size: .82rem; letter-spacing: .2em; color: var(--ink-faint); }

/* ---------- 对比尺（自重 vs 下压力） ---------- */
.scale2 { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(2rem, 5vw, 5rem); margin: clamp(3.5rem, 8vh, 6rem) 0; }
.scale2__col { border-top: 1px solid var(--line); padding-top: 1.6rem; }
.scale2__col .lbl { font-family: var(--font-mono); font-size: .7rem; letter-spacing: .32em; color: var(--ink-faint); text-transform: uppercase; }
.scale2__col .num {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 5vw, 3.8rem);
  font-weight: 400; line-height: 1.1;
  margin: .7rem 0 1.2rem;
}
.scale2__col .num small { font-size: .4em; color: var(--ink-faint); margin-left: .3em; letter-spacing: .08em; }
.scale2__track { position: relative; height: 3px; background: var(--line-soft); }
.scale2__fill { position: absolute; left: 0; top: 0; bottom: 0; width: 0; transition: width 1.8s var(--ease); }
.scale2__col.is-run .scale2__fill { width: var(--w); }
.scale2__fill--self { background: var(--ink-faint); }
.scale2__fill--down { background: var(--accent); }
.scale2__note { display: block; margin-top: 1rem; font-size: 1rem; color: var(--ink-dim); }
.scale2__note b { color: var(--ink); }

/* ---------- 热点探索 ---------- */
.explorer { position: relative; margin: clamp(3.5rem, 8vh, 6rem) 0; }
.explorer__img { position: relative; overflow: hidden; background: #0e0e11; }
.explorer__img img { width: 100%; }
.explorer__hint {
  position: absolute; top: 1.2rem; right: 1.4rem;
  font-family: var(--font-mono); font-size: .72rem;
  letter-spacing: .3em; color: var(--ink-dim);
  background: rgba(11,11,13,.55); backdrop-filter: blur(6px);
  padding: .45rem .9rem;
  border: 1px solid var(--line);
}
.hotspot {
  position: absolute;
  width: 14px; height: 14px;
  border: 1px solid var(--ink-dim);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  cursor: pointer;
  transition: border-color .3s, transform .3s;
}
.hotspot::before {
  content: '';
  position: absolute; inset: 3px;
  border-radius: 50%;
  background: var(--ink-dim);
  transition: background .3s;
}
.hotspot:hover, .hotspot.is-active { border-color: var(--accent); }
.hotspot:hover::before, .hotspot.is-active::before { background: var(--accent); }
.hotspot__label {
  position: absolute; left: 50%; bottom: calc(100% + 1rem);
  transform: translateX(-50%) translateY(6px);
  width: max-content; max-width: 260px;
  background: rgba(11,11,13,.92);
  border: 1px solid var(--line);
  padding: .9rem 1.1rem;
  opacity: 0; pointer-events: none;
  transition: opacity .35s var(--ease), transform .35s var(--ease);
  z-index: 5;
}
.hotspot:hover .hotspot__label, .hotspot.is-active .hotspot__label { opacity: 1; transform: translateX(-50%) translateY(0); }
.hotspot__label b { display: block; font-size: .95rem; color: var(--ink); margin-bottom: .3rem; }
.hotspot__label small { font-size: .78rem; line-height: 1.6; color: var(--ink-dim); }

/* ---------- 规格表 ---------- */
.specs { display: grid; grid-template-columns: repeat(2, 1fr); gap: clamp(2rem, 5vw, 4rem); margin: clamp(3.5rem, 8vh, 6rem) 0; }
.specs__group h3 {
  font-family: var(--font-mono); font-size: .7rem;
  font-weight: 400; letter-spacing: .38em;
  color: var(--ink-faint); text-transform: uppercase;
  margin-bottom: .4rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--line);
}
.specs__row {
  display: flex; justify-content: space-between; align-items: baseline;
  padding: .85rem 0;
  border-bottom: 1px solid var(--line-soft);
  font-size: .95rem;
}
.specs__row .k { color: var(--ink-dim); }
.specs__row .v { font-family: var(--font-display); font-size: 1.15rem; color: var(--ink); letter-spacing: .02em; }
.specs__row .v .unit { font-family: var(--font-mono); font-size: .55em; color: var(--ink-faint); margin-left: .3em; letter-spacing: .1em; }
.specs__row--hl .v { color: var(--accent); }

/* ---------- 视频横幅 ---------- */
.videostrip { position: relative; min-height: 78vh; display: flex; align-items: center; justify-content: center; overflow: hidden; }
.videostrip video { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.videostrip__veil {
  position: absolute; inset: 0;
  background: linear-gradient(to bottom, var(--bg) 0%, rgba(11,11,13,.55) 30%, rgba(11,11,13,.55) 70%, var(--bg) 100%);
}
.videostrip__inner { position: relative; text-align: center; padding: 6rem clamp(1.5rem, 5vw, 4rem); max-width: 44em; }
.videostrip__meta {
  font-family: var(--font-mono); font-size: .78rem;
  letter-spacing: .45em; color: var(--ink-dim);
  text-transform: uppercase;
  display: block; margin-bottom: 1.6rem;
}
.videostrip__inner h2 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(2.2rem, 5.4vw, 4rem);
  line-height: 1.15;
  letter-spacing: .03em;
  margin-bottom: 1.4rem;
}
.videostrip__inner p { color: var(--ink-dim); font-size: 1.05rem; }

/* ---------- 时间线 ---------- */
.timeline { margin: clamp(3rem, 7vh, 5rem) 0; }
.tl-item {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: clamp(1.5rem, 4vw, 4rem);
  padding: clamp(1.8rem, 4vh, 2.8rem) 0;
  border-bottom: 1px solid var(--line-soft);
}
.tl-item:first-child { border-top: 1px solid var(--line-soft); }
.tl-item__date {
  font-family: var(--font-mono); font-size: .8rem;
  letter-spacing: .28em; color: var(--accent);
  text-transform: uppercase;
  padding-top: .4rem;
}
.tl-item h3 { font-family: var(--font-display); font-weight: 400; font-size: clamp(1.25rem, 2.4vw, 1.7rem); letter-spacing: .02em; margin-bottom: .7rem; }
.tl-item p { color: var(--ink-dim); font-size: .98rem; max-width: 46em; }

/* ---------- 引用 ---------- */
.quote { margin: clamp(4rem, 9vh, 7rem) auto; max-width: 780px; text-align: center; }
.quote blockquote {
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 3vw, 2rem);
  line-height: 1.5;
  letter-spacing: .01em;
  color: var(--ink);
}
.quote blockquote .zh {
  display: block;
  font-family: var(--font-text);
  font-size: .55em;
  color: var(--ink-dim);
  line-height: 1.9;
  margin-top: 1.6rem;
  font-style: normal;
}
.quote figcaption { margin-top: 2.2rem; font-family: var(--font-mono); font-size: .8rem; letter-spacing: .3em; color: var(--ink-faint); text-transform: uppercase; }
.quote figcaption b { color: var(--ink-dim); font-weight: 400; }

/* ---------- 新闻档案 ---------- */
.archive { margin: clamp(3.5rem, 8vh, 6rem) 0; }
.archive__head {
  display: flex; justify-content: space-between; align-items: center;
  padding: 1.2rem 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line-soft);
  font-family: var(--font-mono); font-size: .72rem;
  letter-spacing: .3em; color: var(--ink-dim);
  text-transform: uppercase;
  cursor: pointer;
  transition: color .3s;
}
.archive__head:hover { color: var(--ink); }
.archive__body { display: none; padding-top: 2.5rem; }
.archive.is-open .archive__body { display: block; }
.argroup { margin-bottom: 2.6rem; }
.argroup h3 {
  font-family: var(--font-mono); font-size: .68rem;
  font-weight: 400; letter-spacing: .32em;
  color: var(--ink-faint); text-transform: uppercase;
  margin-bottom: .4rem;
}
.ar-item {
  display: grid;
  grid-template-columns: 110px 1fr auto;
  gap: 1.2rem;
  align-items: baseline;
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--line-soft);
  transition: padding-left .3s var(--ease), border-color .3s;
}
.ar-item:hover { padding-left: .8rem; border-color: var(--line); }
.ar-item .d { font-family: var(--font-mono); font-size: .68rem; letter-spacing: .12em; color: var(--ink-faint); }
.ar-item .t { font-size: 1rem; color: var(--ink); }
.ar-item .sum { grid-column: 2; font-size: .86rem; color: var(--ink-faint); line-height: 1.7; }
.ar-item .g { font-family: var(--font-mono); font-size: .62rem; letter-spacing: .25em; color: var(--accent); text-transform: uppercase; opacity: 0; transition: opacity .3s; }
.ar-item:hover .g { opacity: 1; }

/* ---------- 页脚 ---------- */
.footer {
  border-top: 1px solid var(--line-soft);
  padding: clamp(3.5rem, 8vh, 5.5rem) clamp(1.5rem, 5vw, 4rem) 3rem;
  display: flex; justify-content: space-between; align-items: flex-end;
  gap: 2rem; flex-wrap: wrap;
}
.footer__brand {
  font-family: var(--font-display);
  font-size: 2rem; letter-spacing: .3em;
  text-transform: uppercase;
}
.footer__brand .sub {
  display: block;
  font-family: var(--font-mono); font-size: .6rem;
  letter-spacing: .4em; color: var(--ink-faint);
  margin-top: .8rem;
}
.footer__meta {
  font-size: .78rem; line-height: 2;
  color: var(--ink-faint);
  text-align: right;
}
.footer__meta a { color: var(--ink-dim); border-bottom: 1px solid var(--line); transition: color .3s; }
.footer__meta a:hover { color: var(--ink); }

/* ---------- 下载按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: .8rem;
  font-family: var(--font-mono); font-size: .8rem;
  letter-spacing: .28em; text-transform: uppercase;
  color: var(--ink);
  border: 1px solid var(--line);
  padding: 1rem 1.6rem;
  transition: border-color .3s, background .3s;
}
.btn:hover { border-color: var(--accent); background: rgba(77, 124, 254, .06); }

/* ---------- 视口动画 ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .9s var(--ease), transform .9s var(--ease); }
.reveal.is-in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .split { grid-template-columns: 1fr; gap: 2.5rem; }
  .split > .prose:last-child { padding-top: 0; }
  .bignums { grid-template-columns: repeat(2, 1fr); }
  .gallery { grid-template-columns: 1fr; }
  .specs { grid-template-columns: 1fr; }
  .scale2 { grid-template-columns: 1fr; }
  .tl-item { grid-template-columns: 1fr; gap: .6rem; }
  .ar-item { grid-template-columns: 1fr; gap: .3rem; }
  .ar-item .sum { grid-column: 1; }
  .hero__data { flex-wrap: wrap; gap: 1.6rem 2.6rem; }
  .figrow { grid-template-columns: 1fr; }
  .footer { flex-direction: column; align-items: flex-start; }
  .footer__meta { text-align: left; }
}

/* ============================================================
   BOLIDE — v6 组件层（追加）
   学 tourbillon luxury 层：章节分隔章、视频图文卡、图卡、历史数字卡
   视觉语言：近黑底 + 衬线标题 + 极少量蓝点缀 + 玻璃拟态
   ============================================================ */

/* ---------- 章节分隔（全宽 chapter-break） ---------- */
.chapter-break {
  position: relative;
  padding: clamp(5rem, 12vh, 8rem) 0;
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
  background:
    radial-gradient(700px 300px at 80% 0%, rgba(77, 124, 254, 0.06), transparent 60%),
    var(--bg);
  overflow: hidden;
}
.chapter-break__inner {
  max-width: var(--w-doc);
  margin: 0 auto;
  padding: 0 clamp(1.5rem, 5vw, 4rem);
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: clamp(1.5rem, 4vw, 4rem);
  align-items: start;
}
.chapter-break__no {
  font-family: var(--font-display);
  font-size: clamp(3rem, 7vw, 5rem);
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1px rgba(244, 242, 238, 0.22);
}
.chapter-break h2 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(2.2rem, 5vw, 3.6rem);
  line-height: 1.1;
  letter-spacing: .03em;
}
.chapter-break h2 .latin {
  display: block;
  font-family: var(--font-mono);
  font-size: .28em;
  letter-spacing: .5em;
  color: var(--ink-faint);
  margin-top: .9rem;
  text-transform: uppercase;
}
.chapter-break p {
  margin-top: 1.4rem;
  color: var(--ink-dim);
  font-size: 1.05rem;
  max-width: 34em;
}
.chapter-break__meta {
  display: block;
  margin-top: 1.2rem;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .38em;
  color: var(--ink-faint);
  text-transform: uppercase;
}

/* ---------- 视频图文卡 webcard ---------- */
.webcard {
  display: grid;
  grid-template-columns: 1.35fr 1fr;
  gap: 0;
  margin: clamp(3.5rem, 8vh, 6rem) 0;
  border: 1px solid var(--line-soft);
  background: transparent;
  transition: border-color .5s, box-shadow .5s, transform .5s var(--ease);
}
.webcard:hover {
  border-color: rgba(0, 75, 250, 0.5);
}
.webcard__media { position: relative; overflow: hidden; background: #0e0e11; }

.webcard__media .tag {
  position: absolute; top: 1rem; left: 1rem;
  font-family: var(--font-mono); font-size: .6rem;
  letter-spacing: .3em; color: var(--ink);
  background: rgba(11,11,13,.6);
  backdrop-filter: blur(6px);
  padding: .4rem .8rem;
  border: 1px solid var(--line);
}
.webcard__body {
  padding: clamp(1.8rem, 4vw, 3rem);
  display: flex; flex-direction: column; justify-content: center; gap: 1rem;
}
.webcard__body .no {
  font-family: var(--font-mono); font-size: .62rem;
  letter-spacing: .38em; color: var(--accent);
  text-transform: uppercase;
}
.webcard__body h3 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.5rem, 2.8vw, 2.1rem);
  line-height: 1.25;
  letter-spacing: .02em;
}
.webcard__body p { color: var(--ink-dim); font-size: 1.02rem; line-height: 1.85; }
.webcard__body p b { color: var(--ink); }
.webcard__body .meta {
  font-family: var(--font-mono); font-size: .82rem;
  letter-spacing: .28em; color: var(--ink-faint);
  text-transform: uppercase;
}
.webcard--flip { grid-template-columns: 1fr 1.35fr; }
.webcard--flip .webcard__body { order: 2; }

/* ---------- 图卡 dcard ---------- */
.dcards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(1rem, 2vw, 1.6rem);
  margin: clamp(3rem, 7vh, 5rem) 0;
}
.dcard {
  overflow: hidden;
}
.dcard img {
  width: 100%; aspect-ratio: 16/11; object-fit: cover;
  filter: saturate(.92);
  transition: transform 1.1s var(--ease), filter .5s;
}
.dcard:hover img { transform: scale(1.04); filter: saturate(1); }
.dcard__body { padding: 1.4rem 1.5rem 1.7rem; }
.dcard__body .no {
  font-family: var(--font-mono); font-size: .6rem;
  letter-spacing: .34em; color: var(--ink-faint);
  text-transform: uppercase;
  display: block; margin-bottom: .5rem;
}
.dcard__body h3 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 1.3rem;
  letter-spacing: .02em;
  margin-bottom: .55rem;
}
.dcard__body p { color: var(--ink-dim); font-size: 1rem; line-height: 1.8; }
.dcard__body p b { color: var(--ink); }

/* ---------- 历史数字卡 hcard ---------- */
.hcards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(1rem, 2vw, 1.6rem);
  margin: clamp(3rem, 7vh, 5rem) 0;
}
.hcard {
  border-top: 1px solid var(--line);
  padding-top: 1.6rem;
  transition: border-color .5s;
}
.hcard:hover { border-color: rgba(77, 124, 254, 0.5); }
.hcard__year {
  font-family: var(--font-mono); font-size: .78rem;
  letter-spacing: .3em; color: var(--accent);
  text-transform: uppercase;
}
.hcard h3 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 1.5rem;
  margin: .6rem 0 .4rem;
}
.hcard__num {
  font-family: var(--font-mono); font-size: .8rem;
  letter-spacing: .2em; color: var(--ink);
  display: block; margin-bottom: .8rem;
}
.hcard p { color: var(--ink-faint); font-size: 1rem; line-height: 1.8; }

/* ---------- 引用行内（章节内小引） ---------- */
.inline-quote {
  margin: clamp(2.5rem, 6vh, 4rem) 0;
  padding: 0 0 0 clamp(1.5rem, 3vw, 2.5rem);
  border-left: 2px solid var(--accent);
}
.inline-quote p {
  font-family: var(--font-display);
  font-size: clamp(1.15rem, 2.2vw, 1.5rem);
  line-height: 1.6;
  color: var(--ink-dim);
}
.inline-quote p b { color: var(--ink); font-weight: 400; }
.inline-quote footer {
  margin-top: .9rem;
  font-family: var(--font-mono); font-size: .66rem;
  letter-spacing: .3em; color: var(--ink-faint);
  text-transform: uppercase;
}

/* ---------- 数据小卡 stat ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: clamp(1rem, 2vw, 1.6rem);
  margin: clamp(2.5rem, 6vh, 4rem) 0;
}
.stat {
  padding: 1.4rem 0 0;
  border-top: 1px solid var(--line-soft);
}
.stat b {
  display: block;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.7rem, 3.4vw, 2.4rem);
  line-height: 1.1;
}
.stat b em { font-style: normal; color: var(--accent); }
.stat span {
  display: block;
  font-family: var(--font-mono); font-size: .78rem;
  letter-spacing: .3em; color: var(--ink-faint);
  text-transform: uppercase;
  margin-top: .5rem;
}

@media (max-width: 900px) {
  .webcard, .webcard--flip { grid-template-columns: 1fr; }
  .webcard--flip .webcard__body { order: 0; }
  
  .dcards, .hcards { grid-template-columns: 1fr; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .chapter-break__inner { grid-template-columns: 1fr; gap: 1rem; }
}

/* ============================================================
   BOLIDE — v7 文案层级层（追加）
   强化 lead/正文区分，新增编号要点卡 .points
   ============================================================ */

/* lead 与正文拉开层级 */
.prose .lead {
  font-size: clamp(1.28rem, 2.3vw, 1.5rem);
  line-height: 1.72;
  color: var(--ink);
  letter-spacing: .005em;
  margin-bottom: 1.3em;
}
.prose p { color: var(--ink-dim); }
.prose p b { color: var(--ink); font-weight: 700; }

/* 编号要点卡 */
.points {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(1.2rem, 2.4vw, 2rem);
  margin: clamp(3rem, 7vh, 5rem) 0;
}
.point {
  border-top: 1px solid var(--line);
  padding-top: 1.3rem;
  transition: border-color .4s;
}
.point:hover { border-color: rgba(77, 124, 254, 0.5); }
.point__no {
  display: block;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .34em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: .7rem;
}
.point h3 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 1.28rem;
  letter-spacing: .02em;
  margin-bottom: .5rem;
}
.point p {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--ink-faint);
}
.point p b { color: var(--ink-dim); font-weight: 400; }

/* 章节内分组小标签（section label） */
.sec-label {
  display: flex; align-items: center; gap: 1rem;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .4em;
  color: var(--ink-faint);
  text-transform: uppercase;
  margin: clamp(3rem, 7vh, 4.5rem) 0 1.6rem;
}
.sec-label::after { content: ''; flex: 1; height: 1px; background: var(--line-soft); }

/* 正文压缩后的段落间距 */
.prose p + p { margin-top: 1.05em; }
.split .prose { padding-top: .4rem; }

@media (max-width: 900px) {
  .points { grid-template-columns: 1fr; }
}

/* ============================================================
   BOLIDE — v8 交互与视觉强化（追加）
   基于超跑官网设计铁律：数字即英雄 / 限量声明独立区块 /
   画廊轮播 / 规格 tab / 章节呼吸过渡
   ============================================================ */

/* ---------- Hero 数据条：大数字 + 小标签 ---------- */
.hero__data b {
  font-size: clamp(2.6rem, 5.4vw, 4.6rem);
}
.hero__data {
  gap: clamp(2.4rem, 6vw, 5.5rem);
  margin-top: clamp(2.4rem, 6vh, 3.6rem);
}

/* ---------- 限量声明区块 ---------- */
.limited {
  position: relative;
  min-height: 46vh;
  display: flex; align-items: center; justify-content: center;
  text-align: center;
  overflow: hidden;
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}
.limited__media { position: absolute; inset: 0; }
.limited__media img { width: 100%; height: 100%; object-fit: cover; opacity: .32; }
.limited__veil {
  position: absolute; inset: 0;
  background: linear-gradient(to bottom, var(--bg) 0%, rgba(11,11,13,.35) 40%, rgba(11,11,13,.35) 60%, var(--bg) 100%);
}
.limited__inner { position: relative; padding: 5rem clamp(1.5rem, 5vw, 4rem); }
.limited__num {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(3.2rem, 8vw, 6rem);
  line-height: .95;
  letter-spacing: .02em;
  color: var(--ink);
}
.limited__num em { font-style: normal; color: var(--accent); }
.limited__label {
  display: block;
  margin-top: 1.2rem;
  font-family: var(--font-mono);
  font-size: clamp(.72rem, 1.4vw, .9rem);
  letter-spacing: .5em;
  color: var(--ink-dim);
  text-transform: uppercase;
}

/* ---------- 画廊轮播（草图） ---------- */
.slider { margin: clamp(3.5rem, 8vh, 6rem) 0; }
.slider__stage {
  position: relative;
  overflow: hidden;
  background: #0e0e11;
  aspect-ratio: 16/9;
}
.slider__stage img {
  position: absolute; inset: 0;
  width: 100%; height: 100%; object-fit: cover;
  opacity: 0; transform: scale(1.03);
  transition: opacity .7s var(--ease), transform 1.2s var(--ease);
}
.slider__stage img.is-on { opacity: 1; transform: scale(1); }
.slider__cap {
  margin-top: .9rem;
  display: flex; justify-content: space-between; align-items: baseline;
  gap: 1rem;
}
.slider__cap .info { font-size: .88rem; color: var(--ink-dim); }
.slider__cap .info span { display: block; font-family: var(--font-mono); font-size: .62rem; letter-spacing: .3em; color: var(--ink-faint); text-transform: uppercase; margin-bottom: .25rem; }
.slider__nav { display: flex; gap: .6rem; }
.slider__btn {
  width: 44px; height: 44px;
  background: none; border: 1px solid var(--line);
  color: var(--ink-dim);
  font-family: var(--font-mono); font-size: 1rem;
  cursor: pointer;
  transition: border-color .3s, color .3s, background .3s;
}
.slider__btn:hover { border-color: var(--accent); color: var(--ink); }
.slider__count {
  font-family: var(--font-mono); font-size: .7rem;
  letter-spacing: .3em; color: var(--ink-faint);
}

/* ---------- 规格 tab ---------- */
.specs-tabs { margin: clamp(3.5rem, 8vh, 6rem) 0; }
.specs-tabs__nav {
  display: flex; flex-wrap: wrap; gap: .4rem;
  border-bottom: 1px solid var(--line);
  margin-bottom: 2rem;
}
.specs-tabs__btn {
  background: none; border: 0;
  padding: .9rem 1.4rem;
  font-family: var(--font-mono); font-size: .8rem;
  letter-spacing: .3em; color: var(--ink-faint);
  text-transform: uppercase;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: color .3s, border-color .3s;
}
.specs-tabs__btn:hover { color: var(--ink-dim); }
.specs-tabs__btn.is-on { color: var(--ink); border-color: var(--accent); }
.specs-tabs__panel { display: none; }
.specs-tabs__panel.is-on { display: block; animation: tabIn .5s var(--ease); }
@keyframes tabIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }
.specs-tabs .specs__group h3 { display: none; }

/* ---------- 全宽过渡图（章节间呼吸） ---------- */
.breath {
  position: relative;
  height: 64vh;
  overflow: hidden;
}
.breath img { width: 100%; height: 100%; object-fit: cover; }
.breath__veil {
  position: absolute; inset: 0;
  background: linear-gradient(to bottom, var(--bg) 0%, rgba(11,11,13,.25) 30%, rgba(11,11,13,.25) 70%, var(--bg) 100%);
}
.breath__cap {
  position: absolute; bottom: 1.6rem; left: 50%; transform: translateX(-50%);
  font-family: var(--font-mono); font-size: .6rem;
  letter-spacing: .35em; color: var(--ink-faint);
  text-transform: uppercase;
  white-space: nowrap;
}

/* ---------- 补充内容小卡（facts 组） ---------- */
.facts {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: clamp(1rem, 2vw, 1.6rem);
  margin: clamp(3rem, 7vh, 5rem) 0;
}
.fact {
  padding: 1.3rem 0 0;
  border-top: 1px solid var(--line-soft);
  transition: border-color .4s;
}
.fact:hover { border-color: rgba(77, 124, 254, 0.5); }
.fact .no {
  display: block;
  font-family: var(--font-mono); font-size: .62rem;
  letter-spacing: .3em; color: var(--accent);
  text-transform: uppercase;
  margin-bottom: .6rem;
}
.fact h3 { font-family: var(--font-display); font-weight: 400; font-size: 1.15rem; margin-bottom: .45rem; letter-spacing: .02em; }
.fact p { font-size: 1rem; line-height: 1.75; color: var(--ink-faint); }
.fact p b { color: var(--ink-dim); font-weight: 400; }

@media (max-width: 900px) {
  .facts { grid-template-columns: repeat(2, 1fr); }
  .breath { height: 44vh; }
  .hero__data b { font-size: clamp(2.2rem, 9vw, 3.2rem); }
}

/* ============================================================
   BOLIDE — v9 章节视频层（追加）
   官网 moodcut 章节视频：每章一个全宽视频区（视频 + 遮罩 + 标题叠加）
   ============================================================ */

/* 章节视频区 */
.chapter-video {
  position: relative;
  min-height: 68vh;
  display: flex; align-items: center; justify-content: center;
  overflow: hidden;
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}
.chapter-video video {
  position: absolute; inset: 0;
  width: 100%; height: 100%; object-fit: cover;
}
.chapter-video__veil {
  position: absolute; inset: 0;
  background:
    linear-gradient(to bottom, rgba(11,11,13,.78) 0%, rgba(11,11,13,.18) 34%, rgba(11,11,13,.18) 66%, rgba(11,11,13,.82) 100%);
}
.chapter-video__inner {
  position: relative;
  text-align: center;
  padding: 5rem clamp(1.5rem, 5vw, 4rem);
  max-width: 40em;
}
.chapter-video__no {
  display: block;
  font-family: var(--font-mono); font-size: .78rem;
  letter-spacing: .5em; color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 1.4rem;
}
.chapter-video h3 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(2rem, 5vw, 3.4rem);
  line-height: 1.15;
  letter-spacing: .03em;
  color: var(--ink);
  margin-bottom: 1.1rem;
}
.chapter-video p {
  color: var(--ink-dim);
  font-size: 1.02rem;
  line-height: 1.85;
}
.chapter-video p b { color: var(--ink); font-weight: 400; }

/* 章节内嵌视频（16:9 图框式，非全宽） */
.vframe {
  position: relative;
  margin: clamp(3rem, 7vh, 5rem) 0;
  border: 1px solid var(--line-soft);
  background: #0e0e11;
  overflow: hidden;
}
.vframe video { display: block; width: 100%; aspect-ratio: 16/9; object-fit: cover; }
.vframe__cap {
  display: flex; justify-content: space-between; align-items: center; gap: 1rem;
  padding: 1rem 1.2rem;
  font-size: .84rem; color: var(--ink-faint);
  border-top: 1px solid var(--line-soft);
}
.vframe__cap .t { color: var(--ink-dim); }
.vframe__cap .no { font-family: var(--font-mono); font-size: .62rem; letter-spacing: .3em; color: var(--accent); text-transform: uppercase; }

/* 章节标题微调：视频区前的 section 少用重复卡，节奏变化 */
.chapter--tight { padding-top: clamp(2.5rem, 5vh, 4rem); }

/* ============================================================
   结尾区 — 参照 tourbillon.hypercar.site
   portal（更多传奇） / contact（BILIBILI·YOUTUBE）/ top / disclaimer
   ============================================================ */
.footer {
  border-top: 1px solid var(--line-soft);
  padding: clamp(3rem, 7vh, 4.5rem) clamp(1.5rem, 5vw, 4rem) 3rem;
  flex-direction: column;
  align-items: stretch;
}

.footer__portal {
  position: relative;
  overflow: hidden;
  text-align: center;
  padding: clamp(3.5rem, 9vh, 5.5rem) 24px clamp(3.5rem, 9vh, 5.5rem);
  margin-bottom: clamp(2.5rem, 6vh, 4rem);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: radial-gradient(ellipse 90% 70% at 50% 0%, rgba(77, 124, 254, 0.08), transparent 72%);
}
.footer__portal::before {
  content: 'HYPERCAR';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: clamp(64px, 13vw, 180px);
  letter-spacing: 0.1em;
  line-height: 1;
  white-space: nowrap;
  font-family: var(--font-mono);
  color: transparent;
  -webkit-text-stroke: 1px rgba(255, 255, 255, 0.06);
  pointer-events: none;
  user-select: none;
}
.footer__portal-inner {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.footer__portal-kicker {
  font-size: 12px;
  letter-spacing: 0.42em;
  color: var(--accent);
  margin-bottom: 20px;
}
.footer__portal-title {
  font-size: clamp(34px, 5.5vw, 56px);
  font-weight: 400;
  letter-spacing: 0.06em;
  line-height: 1.05;
  color: var(--ink);
}
.footer__portal-dot { color: var(--accent); }
.footer__portal-sub {
  font-size: 14px;
  letter-spacing: 0.22em;
  color: var(--ink-dim);
  margin-top: 14px;
  margin-bottom: 36px;
}
.footer__portal-btn {
  font-size: 13px;
  letter-spacing: 0.26em;
  color: var(--ink);
  padding: 15px 36px;
  border: 1px solid var(--line);
  transition: border-color 0.3s, color 0.3s, background 0.3s, box-shadow 0.3s;
  display: inline-block;
}
.footer__portal-btn:hover {
  border-color: var(--accent);
  color: #fff;
  background: var(--accent);
  box-shadow: 0 0 36px rgba(77, 124, 254, 0.35);
}

.footer__contact {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 24px 0;
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
  margin-bottom: 26px;
  flex-wrap: wrap;
}
.footer__contact-label {
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--ink-faint);
  margin-right: 6px;
}
.footer__contact-btns { display: flex; gap: 16px; flex-wrap: wrap; margin-left: 6px; }
.footer__contact-btns .sbtn {
  display: inline-flex;
  align-items: center;
  gap: 13px;
  padding: 13px 20px;
  min-width: 236px;
  justify-content: flex-start;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.03);
  color: rgba(255, 255, 255, 0.92);
  text-decoration: none;
  transition: transform 0.35s ease, border-color 0.35s, background 0.35s, box-shadow 0.45s;
}
.footer__contact-btns .sbtn svg { flex: none; width: 22px; height: 22px; opacity: 0.9; transition: color 0.3s; }
.footer__contact-btns .sbtn__txt { display: flex; flex-direction: column; align-items: flex-start; gap: 2px; flex: 1; min-width: 0; }
.footer__contact-btns .sbtn__txt b { font-size: 13px; letter-spacing: 0.24em; font-weight: 700; line-height: 1.2; }
.footer__contact-btns .sbtn__txt small { font-size: 10px; letter-spacing: 0.08em; color: var(--ink-faint); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 100%; }
.footer__contact-btns .sbtn__arrow { font-style: normal; font-size: 15px; opacity: 0; transform: translateX(-7px); transition: opacity 0.3s, transform 0.3s; }
.footer__contact-btns .sbtn:hover { transform: translateY(-3px); }
.footer__contact-btns .sbtn:hover .sbtn__arrow { opacity: 1; transform: none; }
.footer__contact-btns .sbtn--bili:hover { border-color: #00a1d6; background: rgba(0, 161, 214, 0.14); color: #fff; box-shadow: 0 14px 34px -14px rgba(0, 161, 214, 0.5); }
.footer__contact-btns .sbtn--bili:hover svg { color: #00a1d6; }
.footer__contact-btns .sbtn--bili:hover .sbtn__txt small { color: #7fd4ef; }
.footer__contact-btns .sbtn--yt:hover { border-color: #ff0033; background: rgba(255, 0, 51, 0.13); color: #fff; box-shadow: 0 14px 34px -14px rgba(255, 0, 51, 0.5); }
.footer__contact-btns .sbtn--yt:hover svg { color: #ff4d66; }
.footer__contact-btns .sbtn--yt:hover .sbtn__txt small { color: #ff9aa8; }

.footer__top {
  display: flex;
  justify-content: flex-start;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}
.footer__brand { font-size: 13px; letter-spacing: 0.3em; color: var(--ink-dim); }
.footer__links { display: flex; gap: 26px; }
.footer__links a {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--ink);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s, color 0.3s;
}
.footer__links a:hover { border-color: var(--accent); color: #fff; }

.footer__disclaimer p {
  color: var(--ink-dim);
  font-size: 13px;
  line-height: 1.9;
  max-width: 860px;
}
.footer__disclaimer p.mono {
  margin-top: 14px;
  color: var(--ink-faint);
  font-family: var(--font-mono);
  font-size: 12px;
}
.footer__disclaimer p.mono a { color: var(--ink-dim); border-bottom: 1px solid var(--line); transition: color 0.3s; }
.footer__disclaimer p.mono a:hover { color: var(--ink); }

/* 移动端 */
@media (max-width: 640px) {
  .footer__top { flex-direction: column; align-items: flex-start; gap: 14px; }
  .footer__links { flex-wrap: wrap; gap: 16px; }
  .footer__contact-btns { flex-direction: column; width: 100%; margin-left: 0; }
  .footer__contact-btns .sbtn { width: 100%; min-width: 0; }
  .footer__contact { align-items: flex-start; flex-direction: column; }
}

/* ============================================================
   v11 视觉精修 — 图说层级 / 章节仪式感 / 呼吸感
   ============================================================ */

/* 图说：加大、层级分明（历史诉求：图说字太小） */
.figure__cap {
  font-size: 1rem;
}
.figure__cap .en {
  color: var(--ink-dim);
  font-size: 1.02em;
}
.figure__cap .zh {
  color: var(--ink-faint);
  font-size: .92em;
}
.figure__cap .no {
  font-size: .8rem;
}

/* 章节标题区：水印大字 + 更从容的呼吸 */
.chapter-break {
  position: relative;
  overflow: hidden;
}
.chapter-break::after {
  content: attr(data-watermark);
  position: absolute;
  right: clamp(1rem, 4vw, 4rem);
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-display);
  font-size: clamp(6rem, 16vw, 14rem);
  line-height: 1;
  letter-spacing: .06em;
  color: transparent;
  -webkit-text-stroke: 1px rgba(244, 242, 238, .05);
  pointer-events: none;
  user-select: none;
  white-space: nowrap;
}
.chapter-break__inner {
  position: relative;
  z-index: 1;
}

/* hero：数据条数字更大、标题更震撼 */
.hero__title {
  font-size: clamp(4.6rem, 18vw, 15rem);
}
.hero__data b {
  font-size: clamp(2.2rem, 4.6vw, 3.4rem);
}
.hero__data > div {
  gap: .3rem;
}
.hero__data span {
  font-size: .72rem;
  letter-spacing: .34em;
}

/* 引用块：引号质感 + 更高级的留白 */
.quote blockquote {
  position: relative;
  padding: 0 1rem;
}
.quote blockquote::before {
  content: '\201C';
  display: block;
  font-family: var(--font-display);
  font-size: 3.4em;
  line-height: .6;
  color: var(--accent);
  opacity: .55;
  margin-bottom: .2em;
}

/* 章节间距呼吸：figrow / figure 之间 */
.figrow {
  gap: clamp(2rem, 4vw, 3.5rem);
}
.figure {
  margin-bottom: clamp(2.5rem, 5vh, 4rem);
}
.figure--full {
  margin-bottom: clamp(3.5rem, 7vh, 5.5rem);
}

/* 数据卡 hover 微动效 */
.stat, .hcard, .fact, .point {
  transition: transform .4s var(--ease), border-color .4s, background .4s;
}
.stat:hover, .hcard:hover, .fact:hover, .point:hover {
  border-color: rgba(0, 75, 250, 0.5);
}

/* ============================================================
   v12 排版规整 — figrow 图片等高 / 第六章节奏
   ============================================================ */

/* figrow 双图等高裁剪（横竖图混排时对齐） */
.figrow .figure__media img {
  aspect-ratio: 4 / 3;
  object-fit: cover;
}
.figrow .figure__media {
  background: #0e0e11;
}

/* timeline：保留两列 grid，加左侧时间线竖线与节点 */
.timeline {
  position: relative;
}
.timeline::before {
  content: '';
  position: absolute;
  left: clamp(1.6rem, 4vw, 2.6rem);
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(to bottom, var(--line), rgba(244,242,238,.05));
  pointer-events: none;
}
.tl-item {
  position: relative;
}
.tl-item::before {
  content: '';
  position: absolute;
  left: calc(clamp(1.6rem, 4vw, 2.6rem) - 5px);
  top: 1.9rem;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--bg);
  border: 1px solid var(--accent);
  transition: box-shadow .3s;
  z-index: 1;
}
.tl-item:hover::before {
  box-shadow: 0 0 0 5px rgba(77, 124, 254, .18);
}

/* webcard 组：相邻两张时拉开距离 */
.webcard + .webcard {
  margin-top: clamp(2.5rem, 6vh, 4rem);
}
.webcard + .figrow,
.figrow + .webcard {
  margin-top: clamp(2.5rem, 6vh, 4rem);
}

/* chapter-video 与 webcard 相邻的节奏 */
.chapter-video + .webcard {
  margin-top: clamp(3rem, 7vh, 5rem);
}

/* ============================================================
   v13 全面美化 — 质感细节
   ============================================================ */

/* 自定义滚动条（细、低调） */
::-webkit-scrollbar { width: 9px; }
::-webkit-scrollbar-track { background: #0b0b0d; }
::-webkit-scrollbar-thumb {
  background: #232329;
  border-radius: 5px;
  border: 2px solid #0b0b0d;
}
::-webkit-scrollbar-thumb:hover { background: #33333c; }

/* hero：暗角 + 数据条底部光带 */
.hero__veil::after {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(ellipse 120% 90% at 50% 40%, transparent 55%, rgba(11,11,13,.55) 100%);
  pointer-events: none;
}
.hero__data {
  position: relative;
}
.hero__data::after {
  content: '';
  position: absolute;
  left: 0; right: 0; bottom: -1.2rem;
  height: 1px;
  background: linear-gradient(to right, var(--accent), transparent 60%);
  opacity: .5;
}

/* nav：品牌 ✕ 符号发光 */

/* specs tabs：active 底部线 + 悬浮态 */
.specs-tabs__btn {
  background: none; border: none; cursor: pointer;
  font-family: var(--font-mono);
  font-size: .8rem; letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--ink-faint);
  padding: .9rem 1.2rem;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: color .3s, border-color .3s;
}
.specs-tabs__btn:hover { color: var(--ink-dim); }
.specs-tabs__btn.is-on {
  color: var(--ink);
  border-bottom-color: var(--accent);
}

/* facts：卡片化 + 顶部细线 */
.fact {
  border-top: 1px solid var(--line);
  padding-top: 1.4rem;
  position: relative;
}
.fact::before {
  content: '';
  position: absolute;
  top: -1px; left: 0;
  width: 2.6rem; height: 1px;
  background: var(--accent);
  transition: width .5s var(--ease);
}
.fact {
  border-top: 1px solid var(--line-soft);
}
.fact:hover::before { width: 100%; }

/* points：编号微光 */
.point__no {
  font-family: var(--font-mono);
  font-size: .74rem; letter-spacing: .3em;
  color: var(--ink-faint);
  text-transform: uppercase;
}

/* chapter-video：顶部渐变过渡（与上图衔接） */
.chapter-video {
  position: relative;
}
.chapter-video::before {
  content: '';
  position: absolute;
  inset: 0 0 auto 0;
  height: clamp(3rem, 8vh, 6rem);
  background: linear-gradient(to bottom, var(--bg), transparent);
  z-index: 2;
  pointer-events: none;
}

/* figure 图说：编号与文字分隔更清晰 */
.figure__cap .no::after {
  content: '';
  display: inline-block;
  width: 2rem; height: 1px;
  background: var(--accent);
  opacity: .6;
  vertical-align: middle;
  margin-left: .7rem;
}

/* 键盘可达性 */
a:focus-visible, button:focus-visible {
  outline: 1px solid var(--accent);
  outline-offset: 3px;
}

/* ============================================================
   v15 卡片设计 — 借鉴 tourbillon
   统一边框/面板渐变/hover 蓝光晕
   ============================================================ */
.hcard, .dcard, .point, .stat, .webcard, .specs-tabs {
  position: relative;
  border: 1px solid var(--line-soft);
  background: transparent;
  transition: border-color 0.35s, transform 0.35s var(--ease);
}
/* 蓝线部分描边：左侧竖线 */
.hcard::before, .dcard::before, .point::before, .stat::before, .webcard::before {
  content: '';
  position: absolute;
  left: -1px; top: -1px; bottom: -1px;
  width: 2px;
  background: var(--accent);
  opacity: .55;
  transition: opacity 0.35s, width 0.35s;
  pointer-events: none;
}
.hcard:hover, .dcard:hover, .point:hover, .stat:hover, .webcard:hover {
  border-color: rgba(0, 75, 250, 0.5);
  transform: translateY(-2px);
}
.hcard:hover::before, .dcard:hover::before, .point:hover::before, .stat:hover::before, .webcard:hover::before {
  opacity: 1;
  width: 3px;
}

/* hcard 细节（tourbillon 式） */
.hcard {
  padding: clamp(1.8rem, 4vh, 2.4rem) clamp(1.4rem, 3vw, 1.9rem);
}
.hcard h3 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin: .8rem 0 .4rem;
  letter-spacing: .04em;
}
.hcard__num {
  font-size: clamp(1.2rem, 2.2vw, 1.5rem);
  color: var(--accent);
  margin-bottom: .8rem;
}
.hcard p:last-child {
  color: var(--ink-dim);
  font-size: 1rem;
  line-height: 1.8;
}

/* point 卡片 */
.point {
  padding: clamp(1.6rem, 3.5vh, 2.2rem) clamp(1.3rem, 2.6vw, 1.8rem);
}
.point h3 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.3rem, 2.4vw, 1.7rem);
  margin: .7rem 0 .5rem;
}

/* webcard 视频统一 16:9 */


/* facts/stat 也统一卡片化 */
.fact, .stat {
  padding: clamp(1.3rem, 3vh, 1.8rem) clamp(1.1rem, 2.4vw, 1.5rem);
}

/* ============================================================
   v15 补充 — dcard 图片比例 / hero 文案层级 / 其他
   ============================================================ */
.dcard {
  overflow: hidden;
  border: 1px solid var(--line-soft);
  background: transparent;
  transition: border-color 0.35s, transform 0.35s var(--ease);
}
.dcard:hover {
  border-color: rgba(0, 75, 250, 0.5);
  transform: translateY(-2px);
}
.dcard img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  transition: transform 1.2s var(--ease);
}
.dcard:hover img { transform: scale(1.04); }
.dcard__body {
  padding: clamp(1.4rem, 3vw, 1.9rem);
}
.dcard__body .no {
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .3em;
  color: var(--accent);
  text-transform: uppercase;
}
.dcard__body h3 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.3rem, 2.4vw, 1.6rem);
  margin: .6rem 0 .5rem;
}
.dcard__body p {
  font-size: 1rem;
  line-height: 1.85;
  color: var(--ink-dim);
}

/* ============================================================
   v16 溢出保护 + 卡片修正
   ============================================================ */
.hcard, .dcard, .point, .fact, .stat, .webcard, .specs-tabs, .hcard__num, .dcard__body, .webcard__body, .fact p, .point p, .hcard p {
  min-width: 0;
  overflow-wrap: break-word;
  word-break: break-word;
}
.webcard__body {
  padding: clamp(1.6rem, 3.5vh, 2.2rem) clamp(1.3rem, 2.6vw, 1.8rem);
  min-width: 0;
}
.specs-tabs__panel {
  min-width: 0;
}
.specs__row {
  display: flex;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
}
.specs__row .v {
  text-align: right;
  white-space: nowrap;
}

/* ============================================================
   v18 章节标题光效 — 学习 tourbillon（.sec-tag 蓝色辉光）
   ============================================================ */
.chapter-break__no {
  color: transparent;
  -webkit-text-stroke: 1px rgba(0, 75, 250, 0.6);
  text-shadow: 0 0 24px rgba(0, 75, 250, 0.35);
  transition: text-shadow 0.5s, -webkit-text-stroke 0.5s;
}
.chapter-break:hover .chapter-break__no {
  -webkit-text-stroke: 1px rgba(0, 75, 250, 0.9);
  text-shadow: 0 0 40px rgba(0, 75, 250, 0.55);
}
.chapter-break h2 {
  color: var(--ink);
  text-shadow: 0 0 30px rgba(0, 75, 250, 0.25);
}
.chapter-break h2 .latin {
  color: #6f9dff;
  text-shadow: 0 0 14px rgba(0, 75, 250, 0.5);
}
.chapter-break__meta {
  color: var(--ink-dim);
  text-shadow: 0 0 12px rgba(0, 75, 250, 0.2);
}
.chapter-break__meta span, .chapter-break__meta a { color: #6f9dff; }

/* ============================================================
   v22 移动端视频修复 — 消除右侧黑边
   ============================================================ */
video {
  display: block;
  max-width: 100%;
}

/* 全屏/章节背景视频：确保 cover 裁剪、无溢出 */
.hero__media video,
.chapter-video video,
.videostrip video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  min-width: 100%;
  min-height: 100%;
}

/* webcard 视频：容器固定比例，视频 cover 填满（修复手机黑边） */
.webcard__media {
  position: relative;
  overflow: hidden;
  background: #0e0e11;
  aspect-ratio: 16 / 9;
}
.webcard__media video,
.webcard__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}
.webcard__media video {
  position: absolute;
  inset: 0;
}
/* 桌面保持原高度（min-height 300px 由旧规则提供） */

/* 移动端：视频容器高度由比例决定，避免 min-height 拉伸 */
@media (max-width: 900px) {
  
  .webcard__media { aspect-ratio: 16 / 9; }
  .hero__media video { min-height: 100svh; }
}

/* ============================================================
   v22b 视频黑边加固 — Safari/WebView 兼容
   ============================================================ */
video::-webkit-media-controls { }
video {
  /* 确保 iOS/Safari 上视频不显示固有尺寸黑边 */
  background: transparent;
}
.hero__media, .chapter-video, .videostrip, .webcard__media {
  /* 视频容器统一裁切 */
  overflow: hidden;
}

/* 移动端：chapter-video 高度限制，避免过大拉伸 */
@media (max-width: 900px) {
  .chapter-video { min-height: 52vh; }
}