/* 通电边框：暗场里几块黑玻璃，电都画在它们边上。 */
:root {
  --bg: #05060b;
  --ink: #e9eef7;
  --muted: #8b93a7;
  --line: rgba(255, 255, 255, .08);
  --accent: #7df9ff;
}

* { box-sizing: border-box; }

html, body { margin: 0; min-height: 100%; }

body {
  background:
    radial-gradient(120% 80% at 50% -10%, #0d1424 0%, transparent 60%),
    var(--bg);
  color: var(--ink);
  font: 15px/1.65 ui-sans-serif, system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}

/* 一层极淡的网格，暗场才不至于像一块纯黑 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(to right, rgba(255, 255, 255, .025) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, .025) 1px, transparent 1px);
  background-size: 64px 64px;
  pointer-events: none;
}

.top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  max-width: 1040px;
  margin: 0 auto;
  padding: 22px 28px 10px;
}

.top__brand {
  font-size: 14px;
  font-weight: 650;
  letter-spacing: -.01em;
}

.top__meta {
  color: var(--muted);
  font-size: 12px;
  letter-spacing: .14em;
  text-transform: uppercase;
}

.page {
  max-width: 1040px;
  margin: 0 auto;
  padding: 2vh 28px 120px;
}

/* ── 开场 ── */
.intro {
  padding: 6vh 0 8vh;
}

.intro__title {
  margin: 0;
  font-size: clamp(40px, 7.4vw, 84px);
  line-height: 1.04;
  font-weight: 680;
  letter-spacing: -.04em;
}

.intro__title em {
  color: var(--accent);
  font-style: normal;
  text-shadow: 0 0 32px color-mix(in srgb, var(--accent) 55%, transparent);
}

.intro__lede {
  max-width: 46ch;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 15.5px;
}

/* ── 通了电的容器 ──
   引擎会给带 data-border 的元素加上 .electric-border，画布比容器四周各多 64px，
   所以这里不能 overflow: hidden，否则光晕和闪电会被裁掉。 */
.electric-border {
  position: relative;
}

.electric-border__canvas {
  position: absolute;
  pointer-events: none;
}

.hero {
  padding: 46px 44px;
  border-radius: 28px;
  background:
    radial-gradient(100% 120% at 0% 0%, rgba(125, 249, 255, .07), transparent 55%),
    rgba(9, 12, 19, .86);
  box-shadow: 0 40px 120px rgba(0, 0, 0, .5);
}

.hero__tag {
  margin: 0 0 18px;
  color: var(--accent);
  font: 11.5px/1 ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: .18em;
}

.hero__title {
  margin: 0;
  font-size: clamp(26px, 3.4vw, 38px);
  font-weight: 650;
  letter-spacing: -.02em;
}

.hero__text {
  max-width: 44ch;
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 14.5px;
}

.hero__hint {
  margin: 28px 0 0;
  color: rgba(139, 147, 167, .8);
  font-size: 12.5px;
}

/* 胶囊那块：圆角一直收到半高，四角的内容会被电流压住，所以居中放 */
.tile--pill {
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 26px 44px;
}

.tile--pill .tile__num { align-self: center; }
.tile--pill .tile__name { margin: 12px 0 6px; }

/* ── 三个变体 ── */
.grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
  margin-top: 26px;
}

.tile {
  display: flex;
  flex-direction: column;
  min-height: 210px;
  padding: 22px;
  border-radius: 18px;
  background: rgba(10, 13, 20, .86);
}

.tile__num {
  color: var(--muted);
  font: 11px/1 ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: .12em;
}

.tile__name {
  margin: auto 0 6px;
  font-size: 34px;
  font-weight: 650;
  letter-spacing: -.03em;
}

.tile__meta {
  margin: 0;
  color: var(--muted);
  font: 11.5px/1.6 ui-monospace, SFMono-Regular, Menlo, monospace;
}

.note {
  max-width: 62ch;
  margin: 40px 0 0;
  color: var(--muted);
  font-size: 13.5px;
}

.note code {
  padding: 1px 5px;
  border-radius: 4px;
  background: rgba(255, 255, 255, .07);
  color: var(--ink);
  font: 12px/1.6 ui-monospace, SFMono-Regular, Menlo, monospace;
}

/* ── 控制条 ── */
.controls {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 7px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(8, 11, 18, .78);
  backdrop-filter: blur(14px);
}

.ctl {
  padding: 6px 12px;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 12.5px;
  cursor: pointer;
  transition: color .2s ease, background .2s ease;
}

.ctl:hover { color: var(--ink); background: rgba(255, 255, 255, .07); }
.ctl:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.ctl.is-off { color: var(--accent); }

.swatches { display: flex; gap: 7px; }

.swatch {
  width: 16px;
  height: 16px;
  padding: 0;
  border: 1px solid rgba(255, 255, 255, .22);
  border-radius: 50%;
  background: currentColor;
  color: #7df9ff;
  cursor: pointer;
  transition: transform .18s ease, box-shadow .18s ease;
}

.swatch[data-color="#ffb84d"] { color: #ffb84d; }
.swatch[data-color="#ff5db1"] { color: #ff5db1; }
.swatch[data-color="#7dffb2"] { color: #7dffb2; }

.swatch:hover { transform: scale(1.15); }
.swatch.is-on { box-shadow: 0 0 0 2px var(--bg), 0 0 0 3px currentColor, 0 0 14px currentColor; }
.swatch:focus-visible { outline: 2px solid var(--ink); outline-offset: 3px; }

@media (max-width: 860px) {
  .top { padding: 18px; }
  .page { padding: 1vh 18px 110px; }
  .hero { padding: 30px 24px; }
  .grid { grid-template-columns: 1fr; }
  .tile { min-height: 170px; }
  .controls { right: 14px; bottom: 14px; left: 14px; justify-content: space-between; }
}

@media (prefers-reduced-motion: reduce) {
  .swatch, .ctl { transition: none; }
  .intro__title em { text-shadow: none; }
}