/* ============================================================
   ESP32-S3 车载仪表 · 落地页
   暗黑 + 霓虹琥珀 + 玻璃卡片
   ============================================================ */

:root {
  --bg:        #07090d;
  --bg-2:      #0b0e14;
  --line:      rgba(255,255,255,.07);
  --line-2:    rgba(255,255,255,.12);
  --text:      #e8ecf3;
  --text-dim:  #8b94a5;
  --text-mute: #5b6373;
  --amber:     #ff8c14;
  --amber-2:   #ffb64d;
  --cyan:      #35e0d8;
  --radius:    18px;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue", "Segoe UI", sans-serif;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* ---------- 背景层 ---------- */
.bg-grid, .bg-glow, .bg-scan { position: fixed; inset: 0; pointer-events: none; z-index: 0; }

.bg-grid {
  background-image:
    linear-gradient(rgba(255,255,255,.028) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.028) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(circle at 50% 25%, #000 0%, transparent 78%);
  -webkit-mask-image: radial-gradient(circle at 50% 25%, #000 0%, transparent 78%);
}

.bg-glow {
  background: radial-gradient(700px circle at 50% 30%, rgba(255,140,20,.10), transparent 70%);
  transition: background .2s linear;
}

.bg-scan {
  background: repeating-linear-gradient(
    0deg, rgba(255,255,255,.014) 0 1px, transparent 1px 3px
  );
  opacity: .55;
  mix-blend-mode: overlay;
}

/* ---------- 导航 ---------- */
.nav {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px;
  padding: 14px clamp(18px, 5vw, 56px);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  background: rgba(7,9,13,.72);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex; align-items: center; gap: 10px;
  text-decoration: none; color: var(--text);
  font-weight: 700; letter-spacing: .14em; font-size: 14px;
}

.brand-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 12px var(--amber), 0 0 26px rgba(255,140,20,.5);
  animation: pulse 2.4s ease-in-out infinite;
}

@keyframes pulse {
  0%,100% { opacity: 1; transform: scale(1); }
  50%     { opacity: .55; transform: scale(.85); }
}

.brand-text .dim { color: var(--text-mute); margin: 0 1px; }

.nav-links { display: flex; align-items: center; gap: clamp(10px, 2vw, 26px); }

.nav-links a {
  color: var(--text-dim); text-decoration: none;
  font-size: 13.5px; letter-spacing: .02em;
  transition: color .2s;
}
.nav-links a:hover { color: var(--text); }

.nav-cta {
  padding: 7px 14px;
  border: 1px solid var(--line-2);
  border-radius: 999px;
  color: var(--text) !important;
  transition: border-color .2s, box-shadow .2s, transform .2s;
}
.nav-cta:hover {
  border-color: rgba(255,140,20,.55);
  box-shadow: 0 0 0 3px rgba(255,140,20,.10), 0 0 22px rgba(255,140,20,.22);
  transform: translateY(-1px);
}

/* ---------- Hero ---------- */
.hero {
  position: relative; z-index: 1;
  padding: clamp(56px, 9vw, 116px) clamp(18px, 5vw, 56px) clamp(40px, 6vw, 72px);
  text-align: center;
}

.hero-badge {
  display: inline-block;
  font-family: var(--mono);
  font-size: 11.5px; letter-spacing: .18em;
  color: var(--amber-2);
  padding: 6px 14px;
  border: 1px solid rgba(255,140,20,.28);
  border-radius: 999px;
  background: rgba(255,140,20,.06);
  margin-bottom: 26px;
}

.hero-title {
  margin: 0 0 20px;
  font-size: clamp(38px, 7.4vw, 84px);
  line-height: 1.06;
  letter-spacing: -.02em;
  font-weight: 800;
}

.hero-title .accent {
  background: linear-gradient(100deg, var(--amber), var(--amber-2));
  -webkit-background-clip: text; background-clip: text;
  color: transparent;
  filter: drop-shadow(0 0 26px rgba(255,140,20,.35));
}

.hero-title .accent2 {
  background: linear-gradient(100deg, var(--cyan), #7ef0ff);
  -webkit-background-clip: text; background-clip: text;
  color: transparent;
  filter: drop-shadow(0 0 26px rgba(53,224,216,.3));
}

.hero-sub {
  margin: 0 auto 34px;
  max-width: 620px;
  font-size: clamp(14.5px, 1.7vw, 17px);
  color: var(--text-dim);
}

.dim { color: var(--text-mute); }

.hero-actions {
  display: flex; gap: 14px; justify-content: center; flex-wrap: wrap;
  margin-bottom: clamp(40px, 6vw, 70px);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 9px;
  padding: 13px 24px;
  border-radius: 12px;
  font-size: 14.5px; font-weight: 600;
  text-decoration: none;
  transition: transform .18s, box-shadow .25s, border-color .2s, background .2s;
  will-change: transform;
}

.btn-primary {
  color: #100b04;
  background: linear-gradient(100deg, var(--amber-2), var(--amber));
  box-shadow: 0 8px 30px rgba(255,140,20,.28), inset 0 1px 0 rgba(255,255,255,.35);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 44px rgba(255,140,20,.42), inset 0 1px 0 rgba(255,255,255,.45);
}

.btn-ghost {
  color: var(--text);
  border: 1px solid var(--line-2);
  background: rgba(255,255,255,.02);
}
.btn-ghost:hover {
  border-color: rgba(255,255,255,.26);
  background: rgba(255,255,255,.05);
  transform: translateY(-2px);
}

.btn-lg { padding: 16px 30px; font-size: 16px; }

/* ---------- Hero 图 ---------- */
.hero-visual {
  position: relative;
  max-width: 980px;
  margin: 0 auto;
  border-radius: 24px;
  overflow: hidden;
  border: 1px solid var(--line-2);
  background: #05070a;
  box-shadow:
    0 40px 120px -30px rgba(0,0,0,.9),
    0 0 0 1px rgba(255,255,255,.03) inset,
    0 0 90px -20px rgba(255,140,20,.18);
}

.hero-visual img { display: block; width: 100%; height: auto; }

.hero-visual::after {
  content: "";
  position: absolute; inset: 0;
  background: linear-gradient(180deg, transparent 62%, rgba(7,9,13,.55));
  pointer-events: none;
}

/* ---------- 通用 Section ---------- */
.section {
  position: relative; z-index: 1;
  padding: clamp(56px, 8vw, 104px) clamp(18px, 5vw, 56px);
}

.section-alt {
  background: linear-gradient(180deg, transparent, rgba(255,255,255,.018) 18%, rgba(255,255,255,.018) 82%, transparent);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.section-head {
  max-width: 1120px;
  margin: 0 auto clamp(30px, 5vw, 52px);
}

.section-idx {
  display: block;
  font-family: var(--mono);
  font-size: 12px; letter-spacing: .22em;
  color: var(--amber);
  opacity: .85;
  margin-bottom: 10px;
}

.section-head h2 {
  margin: 0 0 8px;
  font-size: clamp(26px, 4vw, 40px);
  letter-spacing: -.02em;
  font-weight: 750;
}

.section-desc { margin: 0; color: var(--text-dim); font-size: 15px; }

/* ---------- 表盘卡片 ---------- */
.cards {
  max-width: 1120px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(232px, 1fr));
  gap: clamp(14px, 2vw, 22px);
}

.card {
  padding: 16px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: linear-gradient(170deg, rgba(255,255,255,.045), rgba(255,255,255,.012));
  backdrop-filter: blur(6px);
  transition: transform .28s cubic-bezier(.2,.7,.3,1), border-color .28s, box-shadow .28s;
}

.card:hover {
  transform: translateY(-6px);
  border-color: rgba(255,140,20,.34);
  box-shadow: 0 24px 60px -24px rgba(0,0,0,.9), 0 0 40px -14px rgba(255,140,20,.3);
}

.card-img {
  border-radius: 12px;
  overflow: hidden;
  background: #04060a;
  margin-bottom: 14px;
  aspect-ratio: 1;
}

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

.card h3 { margin: 0 0 5px; font-size: 16.5px; font-weight: 650; letter-spacing: .01em; }
.card p  { margin: 0; font-size: 13.5px; color: var(--text-dim); line-height: 1.55; }
.card code {
  font-family: var(--mono); font-size: 12px;
  background: rgba(255,255,255,.07);
  padding: 1px 5px; border-radius: 4px;
}

/* ---------- 三态 ---------- */
.stages {
  max-width: 1120px;
  margin: 0 auto 26px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  background: #04060a;
}
.stages img { display: block; width: 100%; height: auto; }

.stage-legend {
  max-width: 1120px;
  margin: 0 auto;
  display: flex; flex-wrap: wrap; gap: 10px 26px;
  justify-content: center;
  font-size: 14px; color: var(--text-dim);
  font-family: var(--mono);
}

.dot {
  display: inline-block; width: 8px; height: 8px;
  border-radius: 50%; margin-right: 8px; vertical-align: middle;
}
.d1 { background: #6ee7a8; box-shadow: 0 0 10px #6ee7a8; }
.d2 { background: var(--amber); box-shadow: 0 0 10px var(--amber); }
.d3 { background: #ff4d4d; box-shadow: 0 0 10px #ff4d4d; }

/* ---------- 规格 ---------- */
.spec-wrap {
  max-width: 1120px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0,.85fr) minmax(0,1.15fr);
  gap: clamp(20px, 4vw, 44px);
  align-items: start;
}

.spec-img {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  background: #fff;
}
.spec-img img { display: block; width: 100%; height: auto; }

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

.spec-list li {
  display: grid;
  grid-template-columns: 84px 1fr;
  grid-template-areas: "k v" "k e";
  gap: 0 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}
.spec-list li:first-child { border-top: 1px solid var(--line); }

.spec-list span {
  grid-area: k;
  font-family: var(--mono); font-size: 12px;
  letter-spacing: .12em; color: var(--text-mute);
  text-transform: uppercase;
  align-self: center;
}
.spec-list b  { grid-area: v; font-weight: 620; font-size: 15px; }
.spec-list em { grid-area: e; font-style: normal; font-size: 12.5px; color: var(--text-dim); }

.spec-list li.hl b { color: #7ef0ff; }
.spec-list li.hl { position: relative; }
.spec-list li.hl::before {
  content: ""; position: absolute; left: -14px; top: 10px; bottom: 10px;
  width: 2px; border-radius: 2px;
  background: linear-gradient(180deg, var(--cyan), transparent);
  box-shadow: 0 0 14px rgba(53,224,216,.7);
}

/* ---------- 技术栈 ---------- */
.stack {
  max-width: 1120px;
  margin: 0 auto clamp(30px, 5vw, 52px);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: clamp(12px, 2vw, 20px);
}

.stack-item {
  padding: 20px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.022);
}
.stack-item h4 {
  margin: 0 0 7px; font-size: 13px;
  letter-spacing: .16em; text-transform: uppercase;
  color: var(--amber-2); font-family: var(--mono);
}
.stack-item p { margin: 0; font-size: 14px; color: var(--text-dim); }
.stack-item code {
  font-family: var(--mono); font-size: 12.5px;
  background: rgba(255,255,255,.07); padding: 1px 5px; border-radius: 4px;
}

.app-shot {
  max-width: 460px;
  margin: 0 auto;
  text-align: center;
}
.app-shot img {
  display: block; width: 100%; height: auto;
  border-radius: 26px;
  border: 1px solid var(--line-2);
  box-shadow: 0 30px 80px -30px rgba(0,0,0,.9);
}
.app-shot-cap { margin: 14px 0 0; font-size: 13px; color: var(--text-mute); font-family: var(--mono); }

/* ---------- CTA ---------- */
.cta {
  position: relative; z-index: 1;
  padding: clamp(60px, 9vw, 120px) clamp(18px, 5vw, 56px);
  text-align: center;
  border-top: 1px solid var(--line);
  background:
    radial-gradient(700px circle at 50% 0%, rgba(255,140,20,.10), transparent 68%),
    var(--bg);
}

.cta-inner { max-width: 640px; margin: 0 auto; }

.cta h2 {
  margin: 0 0 14px;
  font-size: clamp(28px, 4.6vw, 46px);
  letter-spacing: -.02em; font-weight: 800;
}

.cta p { margin: 0 0 30px; color: var(--text-dim); font-size: 15.5px; }

.cta-repo {
  margin-top: 20px !important;
  font-family: var(--mono);
  font-size: 12.5px !important;
  letter-spacing: .1em;
  color: var(--text-mute) !important;
}

/* ---------- 页脚 ---------- */
.footer {
  position: relative; z-index: 1;
  padding: 40px clamp(18px, 5vw, 56px) 56px;
  border-top: 1px solid var(--line);
  background: var(--bg-2);
}

.disclaimer {
  max-width: 760px;
  margin: 0 auto 26px;
  padding: 16px 20px;
  border-radius: 12px;
  border: 1px solid rgba(255,140,20,.20);
  background: rgba(255,140,20,.045);
  font-size: 13px;
  color: var(--text-dim);
  line-height: 1.7;
  text-align: center;
}
.disclaimer b { color: var(--amber-2); }

.footer-meta {
  display: flex; justify-content: center; flex-wrap: wrap; gap: 10px;
  font-family: var(--mono);
  font-size: 11.5px; letter-spacing: .1em;
  color: var(--text-mute);
}
.footer-meta .sep { opacity: .4; }

/* ---------- 滚动渐显 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity .7s cubic-bezier(.2,.7,.3,1), transform .7s cubic-bezier(.2,.7,.3,1);
}
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  .brand-dot { animation: none; }
  html { scroll-behavior: auto; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 820px) {
  .spec-wrap { grid-template-columns: 1fr; }
  .nav-links a:not(.nav-cta) { display: none; }
  .hero-visual { border-radius: 16px; }
  .cards { grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); }
  .card { padding: 12px; }
  .card h3 { font-size: 15px; }
  .card p { font-size: 12.5px; }
}

@media (max-width: 480px) {
  .spec-list li { grid-template-columns: 70px 1fr; }
  .stage-legend { font-size: 12px; }
}