:root {
  --red: #e60012;
  --red-dark: #b8000e;
  --ink: #101418;
  --ink-2: #3a4249;
  --muted: #6b757d;
  --line: #e4e8ec;
  --bg: #ffffff;
  --bg-alt: #f5f6f8;
  --dark: #0e1116;
  --radius: 14px;
  --maxw: 1180px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
[hidden] { display: none !important; }
a { color: inherit; text-decoration: none; }
h1, h2, h3 { margin: 0; line-height: 1.2; letter-spacing: -0.01em; }
p { margin: 0; }
ul, dl { margin: 0; padding: 0; list-style: none; }
button { font-family: inherit; }

/* ---------- 通用 ---------- */

.eyebrow {
  font-size: 13px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--red);
  font-weight: 700;
  margin-bottom: 12px;
}
.eyebrow--light { color: #ff5a63; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 46px;
  padding: 0 24px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.18s var(--ease), background 0.18s var(--ease), box-shadow 0.18s var(--ease);
}
.btn:hover { transform: translateY(-2px); }
.btn--primary { background: var(--red); color: #fff; box-shadow: 0 8px 22px rgba(230, 0, 18, 0.24); }
.btn--primary:hover { background: var(--red-dark); }
.btn--ghost { border-color: var(--line); color: var(--ink); background: #fff; }
.btn--ghost:hover { border-color: var(--ink); }
.btn--ghost-light { border-color: rgba(255, 255, 255, 0.45); color: #fff; background: transparent; }
.btn--ghost-light:hover { border-color: #fff; }
.btn--sm { height: 38px; padding: 0 18px; font-size: 14px; }

.section { max-width: var(--maxw); margin: 0 auto; padding: 96px 24px; }
.section--tight { padding-top: 48px; }
.section--alt { max-width: none; background: var(--bg-alt); padding: 96px 24px; }
.section--alt > * { max-width: var(--maxw); margin-inline: auto; }

.section__head { max-width: 720px; margin-bottom: 44px; }
.section__title { font-size: clamp(28px, 4vw, 40px); font-weight: 800; }
.section__lead { margin-top: 14px; color: var(--ink-2); font-size: 16px; }

.reveal { opacity: 0; transform: translateY(26px); transition: opacity 0.7s var(--ease), transform 0.7s var(--ease); }
.reveal.is-visible { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ---------- 滚动进度条 ---------- */

.scroll-progress {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 3px;
  background: var(--red);
  transform: scaleX(0);
  transform-origin: 0 50%;
  z-index: 80;
  pointer-events: none;
}

/* ---------- 导航 ---------- */

.site-nav { position: fixed; inset: 0 0 auto 0; z-index: 60; transition: background 0.25s var(--ease), box-shadow 0.25s var(--ease); }
.site-nav.is-scrolled { background: rgba(255, 255, 255, 0.92); backdrop-filter: blur(12px); box-shadow: 0 1px 0 var(--line); }
.site-nav__inner { max-width: var(--maxw); margin: 0 auto; padding: 14px 24px; display: flex; align-items: center; gap: 24px; }
.site-nav__brand { display: flex; align-items: center; gap: 10px; }
.site-nav__logo { width: 30px; height: 30px; object-fit: contain; border-radius: 6px; }
.site-nav__mark { font-size: 19px; font-weight: 800; letter-spacing: 0.02em; color: #fff; }
.site-nav.is-scrolled .site-nav__mark { color: var(--ink); }
.site-nav__links { display: flex; gap: 22px; margin-left: auto; }
.site-nav__links a { font-size: 14px; color: rgba(255, 255, 255, 0.78); padding: 6px 0; border-bottom: 2px solid transparent; transition: color 0.2s var(--ease), border-color 0.2s var(--ease); }
.site-nav.is-scrolled .site-nav__links a { color: var(--ink-2); }
.site-nav__links a:hover, .site-nav__links a.is-active { color: #fff; border-color: var(--red); }
.site-nav.is-scrolled .site-nav__links a:hover,
.site-nav.is-scrolled .site-nav__links a.is-active { color: var(--ink); }

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

.hero-runway { height: 300vh; }
.hero.hero--sticky { position: sticky; top: 0; height: 100vh; min-height: 0; }
.hero { position: relative; display: flex; align-items: flex-end; padding: 0 24px 88px; color: #fff; overflow: hidden; background: var(--dark); }
.hero__canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.hero__fallback { position: absolute; inset: 0; background-size: cover; background-position: center; opacity: 0; transition: opacity 0.6s var(--ease); }
.hero__fallback.is-visible { opacity: 1; }
.hero__scrim { position: absolute; inset: 0; background: linear-gradient(100deg, rgba(8, 10, 14, 0.82) 0%, rgba(8, 10, 14, 0.52) 42%, rgba(8, 10, 14, 0.08) 72%); pointer-events: none; }
.hero__loading { position: absolute; left: 50%; bottom: 28px; transform: translateX(-50%); display: flex; align-items: center; gap: 10px; padding: 8px 14px; border-radius: 999px; background: rgba(8, 10, 14, 0.55); backdrop-filter: blur(6px); font-size: 12px; letter-spacing: 0.08em; color: rgba(255, 255, 255, 0.85); transition: opacity 0.5s var(--ease); z-index: 3; }
.hero__loading.is-done { opacity: 0; }
.hero__loading.is-gone { display: none; }
.hero__loading-bar { width: 90px; height: 2px; background: rgba(255, 255, 255, 0.25); border-radius: 2px; overflow: hidden; }
.hero__loading-bar i { display: block; height: 100%; width: 0; background: var(--accent); transition: width 0.3s ease; }
.hero__hint { position: absolute; right: 56px; bottom: 40px; font-size: 13px; letter-spacing: 0.12em; color: rgba(255, 255, 255, 0.85); background: rgba(8, 10, 14, 0.45); border: 1px solid rgba(255, 255, 255, 0.18); padding: 8px 14px; border-radius: 999px; backdrop-filter: blur(6px); transition: opacity 0.6s var(--ease); pointer-events: none; z-index: 3; animation: hint-pulse 2.4s ease-in-out infinite; }
.hero__hint.is-done { opacity: 0; }
@keyframes hint-pulse { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-5px); } }
.hero__body { position: relative; max-width: var(--maxw); margin: 0 auto; width: 100%; z-index: 2; }
.hero__title { font-size: clamp(36px, 6.4vw, 68px); font-weight: 800; }
.hero__sub { margin-top: 20px; max-width: 520px; color: rgba(255, 255, 255, 0.82); font-size: 17px; }
.hero__actions { margin-top: 32px; display: flex; gap: 14px; flex-wrap: wrap; }
.hero__scroll { position: absolute; right: 24px; bottom: 40px; font-size: 12px; letter-spacing: 0.2em; color: rgba(255, 255, 255, 0.6); writing-mode: vertical-rl; }

/* ---------- 车型：主图 + 热点 ---------- */

.model-tabs { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 12px; margin-bottom: 32px; }
.model-tab { display: flex; flex-direction: column; gap: 4px; padding: 16px 18px; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; cursor: pointer; text-align: left; transition: border-color 0.2s var(--ease), box-shadow 0.2s var(--ease), transform 0.2s var(--ease); }
.model-tab:hover { transform: translateY(-2px); box-shadow: 0 10px 24px rgba(16, 20, 24, 0.07); }
.model-tab.is-active { border-color: var(--red); box-shadow: 0 10px 24px rgba(230, 0, 18, 0.12); }
.model-tab__name { font-weight: 700; font-size: 15px; }
.model-tab__price { font-size: 13px; color: var(--muted); }
.model-tab.is-active .model-tab__price { color: var(--red); }

.model-detail { display: grid; grid-template-columns: 1.05fr 1fr; gap: 48px; align-items: center; padding: 24px; border: 1px solid var(--line); border-radius: 20px; background: #fff; }

.model-visual { position: relative; border-radius: 16px; overflow: hidden; background: var(--dark); }
.model-stage {
  position: relative;
  aspect-ratio: 4 / 3;
  transform: perspective(900px) rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg));
  transition: transform 0.25s ease-out;
}
.stage-layer { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; opacity: 0; transform: scale(1.05); transition: opacity 0.45s var(--ease), transform 0.7s var(--ease); }
.stage-layer.is-active { opacity: 1; transform: scale(1); }
.stage-glow { position: absolute; inset: 0; pointer-events: none; background: radial-gradient(220px circle at var(--mx, 50%) var(--my, 50%), rgba(255, 255, 255, 0.16), transparent 70%); }

.hotspot { position: absolute; transform: translate(-50%, -50%); display: flex; align-items: center; gap: 8px; background: none; border: 0; padding: 0; cursor: pointer; z-index: 6; }
.hotspot__dot { width: 26px; height: 26px; border-radius: 50%; border: 2px solid rgba(255, 255, 255, 0.9); background: rgba(230, 0, 18, 0.85); display: grid; place-items: center; box-shadow: 0 4px 14px rgba(0, 0, 0, 0.35); transition: transform 0.2s var(--ease); flex: none; }
.hotspot__dot i { width: 8px; height: 8px; border-radius: 50%; background: #fff; animation: pulse 1.9s infinite; }
@keyframes pulse { 0% { transform: scale(1); opacity: 0.9; } 70% { transform: scale(2.4); opacity: 0; } 100% { transform: scale(2.4); opacity: 0; } }
.hotspot:hover .hotspot__dot, .hotspot:focus-visible .hotspot__dot { transform: scale(1.18); }
.hotspot__tip { font-size: 12px; color: #fff; background: rgba(14, 17, 22, 0.72); padding: 4px 10px; border-radius: 999px; white-space: nowrap; opacity: 0; transform: translateX(-6px); transition: 0.25s var(--ease); }
.hotspot:hover .hotspot__tip, .hotspot:focus-visible .hotspot__tip { opacity: 1; transform: none; }

.hotspot-card { position: absolute; left: 20px; right: 20px; bottom: 16px; padding: 0; background: none; backdrop-filter: none; color: #fff; text-shadow: 0 1px 3px rgba(0, 0, 0, 0.9), 0 0 12px rgba(0, 0, 0, 0.6); opacity: 0; transform: translateY(12px); transition: 0.3s var(--ease); pointer-events: none; z-index: 4; }
.hotspot-card.is-top { bottom: auto; top: 16px; transform: translateY(-12px); }
.hotspot-card.is-top.is-on { transform: none; }

/* 卡片弹出时，让左上/右上两个角标淡出，避免互相遮挡 */
.model-visual__note, .model-visual__hint { transition: opacity 0.3s var(--ease); }
.model-visual.has-card .model-visual__note,
.model-visual.has-card .model-visual__hint { opacity: 0; }
.hotspot-card.is-on { opacity: 1; transform: none; }
.hotspot-card__label { font-size: 12px; color: #ff5a63; font-weight: 700; letter-spacing: 0.1em; }
.hotspot-card__value { font-size: 20px; font-weight: 800; margin: 2px 0 4px; }
.hotspot-card__desc { font-size: 13px; color: rgba(255, 255, 255, 0.85); }

.model-visual__note { position: absolute; left: 14px; top: 14px; padding: 6px 12px; border-radius: 999px; background: rgba(14, 17, 22, 0.72); color: #fff; font-size: 12px; z-index: 4; }
.model-visual__hint { position: absolute; right: 14px; top: 14px; padding: 5px 12px; border-radius: 999px; background: rgba(14, 17, 22, 0.5); color: rgba(255, 255, 255, 0.75); font-size: 12px; z-index: 4; }

.model-info__name { font-size: clamp(24px, 3vw, 32px); font-weight: 800; }
.model-info__price { margin-top: 10px; font-size: 30px; font-weight: 800; color: var(--red); }
.model-info__price span { font-size: 14px; color: var(--muted); margin-left: 4px; }
.model-highlights { display: flex; flex-wrap: wrap; gap: 8px; margin: 18px 0 22px; }
.model-highlights li { padding: 5px 12px; border-radius: 999px; background: var(--bg-alt); font-size: 13px; color: var(--ink-2); }
.spec-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1px; background: var(--line); border-radius: 12px; overflow: hidden; }
.spec-grid__item { background: #fff; padding: 12px 14px; }
.spec-grid dt { font-size: 12px; color: var(--muted); }
.spec-grid dd { margin: 2px 0 0; font-size: 15px; font-weight: 600; }
.model-actions { margin-top: 24px; display: flex; gap: 12px; flex-wrap: wrap; }

/* ---------- 由内而外：sticky 图 + 滚动推进 ---------- */

.explore__grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: start; }
.explore__stage { position: sticky; top: 96px; aspect-ratio: 4 / 5; border-radius: 20px; overflow: hidden; background: var(--dark); box-shadow: 0 20px 50px rgba(16, 20, 24, 0.14); }
.scene-layer { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; opacity: 0; transform: scale(1.08); transition: opacity 0.65s var(--ease), transform 1s var(--ease); }
.scene-layer.is-active { opacity: 1; transform: scale(1); }

.explore__steps { display: flex; flex-direction: column; }
.scene-step { min-height: 74vh; padding: 24px 0 24px 26px; border-left: 2px solid transparent; opacity: 0.32; transform: translateY(12px); transition: opacity 0.5s var(--ease), transform 0.5s var(--ease), border-color 0.5s var(--ease); }
.scene-step.is-active { opacity: 1; transform: none; border-color: var(--red); }
.scene-step__title { font-size: clamp(22px, 2.6vw, 30px); font-weight: 800; }
.scene-step__text { margin-top: 14px; color: var(--ink-2); max-width: 480px; }
.scene-step__points { display: flex; gap: 30px; margin-top: 26px; flex-wrap: wrap; }
.scene-step__points li { display: flex; flex-direction: column; }
.scene-step__points b { font-size: 26px; font-weight: 800; line-height: 1.1; }
.scene-step__points span { font-size: 12px; color: var(--red); font-weight: 600; }
.scene-step__points em { font-style: normal; font-size: 12px; color: var(--muted); margin-top: 2px; }

/* ---------- 参数表 ---------- */

.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: 16px; }
.spec-table { width: 100%; border-collapse: collapse; min-width: 720px; background: #fff; font-size: 14px; }
.spec-table th, .spec-table td { padding: 14px 18px; text-align: left; border-bottom: 1px solid var(--line); }
.spec-table thead th { background: var(--bg-alt); font-weight: 700; font-size: 13px; }
.spec-table tbody th { color: var(--muted); font-weight: 500; }
.spec-table .is-highlight td { color: var(--red); font-weight: 700; }
.spec-table .is-highlight th { color: var(--ink); font-weight: 700; }

/* ---------- 配置器 ---------- */

.configurator { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 28px; align-items: start; }
.configurator__body { display: flex; flex-direction: column; gap: 26px; }
.config-group__title { font-size: 14px; font-weight: 700; margin-bottom: 12px; }
.config-options { display: flex; gap: 12px; flex-wrap: wrap; }
.config-option { display: flex; align-items: center; gap: 10px; padding: 12px 16px; border: 1px solid var(--line); border-radius: 12px; background: #fff; cursor: pointer; font-size: 14px; transition: border-color 0.18s var(--ease), box-shadow 0.18s var(--ease), transform 0.18s var(--ease); }
.config-option:hover { border-color: var(--ink-2); transform: translateY(-2px); }
.config-option.is-active { border-color: var(--red); box-shadow: 0 0 0 3px rgba(230, 0, 18, 0.1); }
.swatch { width: 20px; height: 20px; border-radius: 50%; border: 1px solid var(--line); }
.config-option__name { font-weight: 600; }
.config-option__delta { color: var(--muted); font-size: 13px; }

.summary { position: sticky; top: 88px; border: 1px solid var(--line); border-radius: 18px; background: #fff; overflow: hidden; }
.summary__visual { position: relative; background: var(--bg-alt); overflow: hidden; transform: perspective(900px) rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg)); transition: transform 0.25s ease-out; }
.summary__visual img { width: 100%; aspect-ratio: 16 / 10; object-fit: cover; }
.swatch--inline { display: inline-block; width: 10px; height: 10px; border-radius: 50%; margin-right: 6px; border: 1px solid rgba(255, 255, 255, 0.55); vertical-align: -1px; }
.summary__badge { position: absolute; left: 12px; bottom: 12px; background: rgba(14, 17, 22, 0.7); color: #fff; font-size: 12px; padding: 5px 12px; border-radius: 999px; }
.summary__body { padding: 24px; }
.summary__body h3 { font-size: 22px; font-weight: 800; }
.summary__list { margin: 16px 0; display: flex; flex-direction: column; gap: 8px; }
.summary__list li { display: flex; justify-content: space-between; font-size: 14px; border-bottom: 1px dashed var(--line); padding-bottom: 8px; }
.summary__list span { color: var(--muted); }
.summary__price { font-size: 28px; font-weight: 800; color: var(--red); }
.summary__hint { font-size: 12px; color: var(--muted); margin: 6px 0 18px; }

/* ---------- 分期计算器 ---------- */

.finance { padding: 20px; border: 1px solid var(--line); border-radius: 16px; background: #fff; }
.finance__row { display: flex; align-items: center; gap: 14px; margin-bottom: 14px; }
.finance__label { font-size: 13px; color: var(--muted); min-width: 60px; }
.finance input[type='range'] { flex: 1; accent-color: var(--red); }
.finance__pct { font-size: 14px; font-weight: 700; min-width: 46px; text-align: right; }
.finance__terms { display: flex; gap: 8px; flex-wrap: wrap; }
.term-btn { padding: 7px 14px; border: 1px solid var(--line); border-radius: 999px; background: #fff; font-size: 13px; cursor: pointer; transition: border-color 0.18s var(--ease), color 0.18s var(--ease); }
.term-btn:hover { border-color: var(--ink-2); }
.term-btn.is-active { border-color: var(--red); color: var(--red); font-weight: 700; }
.finance__result { display: flex; gap: 32px; padding-top: 14px; border-top: 1px dashed var(--line); }
.finance__result div { display: flex; flex-direction: column; }
.finance__result span { font-size: 12px; color: var(--muted); }
.finance__result b { font-size: 22px; font-weight: 800; }
.finance__result .is-accent { color: var(--red); }
.finance__note { font-size: 12px; color: var(--muted); margin-top: 10px; }

/* ---------- FAQ ---------- */

.faq-list { display: flex; flex-direction: column; gap: 10px; max-width: 860px; }
.faq-item { border: 1px solid var(--line); border-radius: 12px; background: #fff; overflow: hidden; }
.faq-item__q { width: 100%; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 18px 20px; background: none; border: 0; cursor: pointer; font-size: 15px; font-weight: 600; text-align: left; color: inherit; }
.faq-item__icon { position: relative; width: 14px; height: 14px; flex: none; }
.faq-item__icon::before, .faq-item__icon::after { content: ''; position: absolute; background: var(--ink-2); transition: transform 0.25s var(--ease), opacity 0.25s var(--ease); }
.faq-item__icon::before { left: 0; top: 6px; width: 14px; height: 2px; }
.faq-item__icon::after { left: 6px; top: 0; width: 2px; height: 14px; }
.faq-item.is-open .faq-item__icon::after { transform: rotate(90deg); opacity: 0; }
.faq-item__a { max-height: 0; overflow: hidden; transition: max-height 0.3s var(--ease); }
.faq-item.is-open .faq-item__a { max-height: 320px; }
.faq-item__a p { padding: 0 20px 20px; color: var(--ink-2); font-size: 14px; }

/* ---------- CTA / Footer ---------- */

.cta { max-width: none; background: var(--dark); color: #fff; padding: 96px 24px; }
.cta__body { max-width: var(--maxw); margin: 0 auto; }
.cta .section__lead { color: rgba(255, 255, 255, 0.76); }

.site-footer { background: var(--bg-alt); padding: 44px 24px; }
.site-footer__inner { max-width: var(--maxw); margin: 0 auto; display: flex; align-items: flex-start; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.site-footer__mark { font-size: 18px; font-weight: 800; letter-spacing: 0.08em; }
.site-footer__note { font-size: 13px; color: var(--muted); }
.site-footer__links { display: flex; gap: 20px; font-size: 14px; color: var(--ink-2); }
.site-footer__desc { width: 100%; font-size: 12px; color: var(--muted); }

/* ---------- 响应式 ---------- */

@media (max-width: 900px) {
  .site-nav__links { display: none; }
  .model-detail { grid-template-columns: 1fr; gap: 28px; }
  .explore__grid { grid-template-columns: 1fr; gap: 24px; }
  .explore__stage { position: static; aspect-ratio: 16 / 10; }
  .scene-step { min-height: 0; padding: 20px 0 20px 20px; }
  .configurator { grid-template-columns: 1fr; }
  .summary { position: static; }
  .section { padding: 64px 20px; }
  .section--alt, .cta { padding: 64px 20px; }
}