:root {
  --ink: #eef7ff;
  --muted: #94a8b8;
  --panel: rgba(10, 20, 35, .82);
  --panel-solid: #0d1929;
  --line: rgba(196, 228, 255, .16);
  --cyan: #6cf6ff;
  --lime: #9dff82;
  --gold: #ffe784;
  --pink: #ff6f91;
  --violet: #bd89ff;
  --bg: #050b13;
  color-scheme: dark;
  font-family: Inter, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-synthesis: none;
}

* { box-sizing: border-box; }
html { min-width: 320px; background: var(--bg); }
body { margin: 0; min-height: 100vh; color: var(--ink); background: var(--bg); }
button, a { font: inherit; }
button { color: inherit; }
a { color: inherit; }

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(circle at 15% 12%, rgba(108, 246, 255, .13), transparent 30rem),
    radial-gradient(circle at 85% 70%, rgba(189, 137, 255, .10), transparent 34rem),
    linear-gradient(140deg, #050b13, #07111d 54%, #04080e);
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: .22;
  background-image: linear-gradient(rgba(255,255,255,.03) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.03) 1px, transparent 1px);
  background-size: 40px 40px;
  mask-image: linear-gradient(to bottom, black, transparent 85%);
}

.eyebrow {
  margin: 0 0 .5rem;
  color: var(--cyan);
  font-size: .72rem;
  font-weight: 800;
  letter-spacing: .18em;
  text-transform: uppercase;
}

.hub-page { padding: clamp(1.2rem, 4vw, 4rem); }
.hub-shell { width: min(1180px, 100%); margin: 0 auto; }

.hub-hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(15rem, .7fr);
  align-items: end;
  min-height: 22rem;
  padding: clamp(2rem, 5vw, 5rem);
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 2rem;
  background: linear-gradient(135deg, rgba(17, 37, 60, .94), rgba(7, 15, 26, .9));
  box-shadow: 0 2rem 5rem rgba(0,0,0,.28);
}

.hub-hero h1 {
  position: relative;
  z-index: 2;
  margin: 0;
  font-size: clamp(3.1rem, 8vw, 7.3rem);
  line-height: .82;
  letter-spacing: -.075em;
}

.hub-hero h1 span { color: transparent; -webkit-text-stroke: 1px rgba(238,247,255,.48); }
.hub-hero .lede { position: relative; z-index: 2; margin: 0; max-width: 30rem; color: #c0cfda; font-size: clamp(1rem, 1.6vw, 1.18rem); line-height: 1.8; }

.hero-orbit { position: absolute; right: 3%; top: -18%; width: 32rem; aspect-ratio: 1; border: 1px solid rgba(108,246,255,.25); border-radius: 50%; animation: orbit-spin 24s linear infinite; }
.hero-orbit::before, .hero-orbit::after { content: ""; position: absolute; inset: 18%; border: 1px dashed rgba(255,231,132,.25); border-radius: 50%; }
.hero-orbit::after { inset: 36%; border-style: solid; border-color: rgba(189,137,255,.32); }
.hero-orbit i { position: absolute; width: 1.1rem; aspect-ratio: 1; border-radius: 50%; background: var(--cyan); box-shadow: 0 0 2rem var(--cyan); }
.hero-orbit i:nth-child(1) { left: 5%; top: 30%; }
.hero-orbit i:nth-child(2) { right: 18%; top: 8%; background: var(--pink); box-shadow: 0 0 2rem var(--pink); }
.hero-orbit i:nth-child(3) { right: 6%; bottom: 28%; background: var(--gold); box-shadow: 0 0 2rem var(--gold); }
@keyframes orbit-spin { to { transform: rotate(360deg); } }

.quick-rule { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; margin: 1rem 0; overflow: hidden; border: 1px solid var(--line); border-radius: 1.25rem; background: var(--line); }
.quick-rule div { display: flex; align-items: center; gap: 1rem; min-height: 6.5rem; padding: 1.25rem 1.5rem; background: rgba(7,15,26,.92); }
.quick-rule strong { color: var(--cyan); font-size: 2rem; font-weight: 300; }
.quick-rule span { color: #b8c7d3; line-height: 1.45; }

.build-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; }
.build-card {
  position: relative;
  min-height: 16rem;
  padding: clamp(1.5rem, 3.5vw, 2.7rem);
  overflow: hidden;
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 1.5rem;
  background: rgba(12, 25, 41, .82);
  transition: transform .2s ease, border-color .2s ease, background .2s ease;
}
.build-card::after { content: ""; position: absolute; right: -3rem; bottom: -4rem; width: 13rem; aspect-ratio: 1; border: 1px solid currentColor; border-radius: 50%; opacity: .12; box-shadow: 0 0 4rem currentColor; }
.build-card:hover, .build-card:focus-visible { transform: translateY(-4px); border-color: currentColor; background: rgba(16,34,54,.96); outline: none; }
.build-card.full { grid-column: 1 / -1; }
.build-card h2 { max-width: 27rem; margin: 1.2rem 0 .8rem; font-size: clamp(1.6rem, 3vw, 2.6rem); line-height: 1.08; letter-spacing: -.04em; }
.build-card p { max-width: 38rem; margin: 0 0 2.2rem; color: #9fb1c0; line-height: 1.7; }
.build-card b { position: absolute; left: clamp(1.5rem, 3.5vw, 2.7rem); bottom: 1.8rem; font-size: .9rem; }
.build-kicker { font-size: .7rem; font-weight: 800; letter-spacing: .15em; }
.accent-cyan { color: var(--cyan); }.accent-lime { color: var(--lime); }.accent-gold { color: var(--gold); }.accent-pink { color: var(--pink); }.accent-violet { color: var(--violet); }
.build-card h2, .build-card p { color: var(--ink); }.build-card p { color: #9fb1c0; }

.hub-footer { display: flex; justify-content: space-between; gap: 2rem; padding: 2rem .5rem 0; color: #738797; font-size: .78rem; }

.game-page { padding: clamp(.7rem, 2vw, 1.6rem); }
.game-shell { width: min(1440px, 100%); margin: 0 auto; }
.game-header { display: grid; grid-template-columns: 10rem 1fr auto; align-items: end; gap: 1.5rem; min-height: 5.5rem; margin-bottom: 1rem; }
.game-header h1 { margin: 0; font-size: clamp(1.5rem, 3vw, 2.7rem); letter-spacing: -.045em; line-height: 1; }
.back-link { align-self: center; color: #9cb0bf; font-size: .82rem; text-decoration: none; }
.back-link:hover { color: var(--cyan); }

.utility-btn {
  min-height: 2.7rem;
  padding: .68rem 1rem;
  cursor: pointer;
  border: 1px solid var(--line);
  border-radius: .8rem;
  background: rgba(15,31,49,.88);
  transition: border-color .15s ease, background .15s ease, transform .15s ease;
}
.utility-btn:hover, .utility-btn:focus-visible { border-color: var(--cyan); background: rgba(28,53,76,.95); outline: none; transform: translateY(-1px); }
kbd { display: inline-grid; place-items: center; min-width: 1.35rem; margin-left: .4rem; padding: .1rem .3rem; border: 1px solid rgba(255,255,255,.2); border-radius: .3rem; color: var(--muted); font-size: .65rem; }

.game-layout { display: grid; grid-template-columns: minmax(0, 1fr) 16.5rem; gap: 1rem; align-items: stretch; }
.stage-card { position: relative; min-width: 0; overflow: hidden; border: 1px solid var(--line); border-radius: 1.25rem; background: #050c14; box-shadow: 0 1.6rem 4rem rgba(0,0,0,.28); }
#game-canvas { display: block; width: 100%; height: auto; aspect-ratio: 16 / 10; touch-action: none; cursor: crosshair; }
.side-rail { display: grid; grid-auto-rows: max-content; gap: .7rem; }
.hud-card, .pulse-card, .how-card, .build-readout { border: 1px solid var(--line); border-radius: 1rem; background: var(--panel); backdrop-filter: blur(14px); }
.hud-card { display: grid; gap: .15rem; padding: 1rem 1.1rem; }
.hud-card span, .pulse-card span, .long-panel span, .social-panel span { color: var(--muted); font-size: .68rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; }
.hud-card strong { color: var(--cyan); font-size: 1.75rem; line-height: 1; }
.hud-card small, .pulse-card small, .long-panel small, .social-panel small { color: #8194a3; font-size: .72rem; }
.score-card strong { font-size: 2.5rem; }
.pulse-card { padding: 1rem 1.1rem; }
.pulse-card > div:first-child { display: flex; justify-content: space-between; align-items: center; }
.pulse-card b { color: var(--lime); font-size: .72rem; }
.meter { height: .35rem; margin: .7rem 0; overflow: hidden; border-radius: 1rem; background: rgba(255,255,255,.08); }
.meter i { display: block; width: 100%; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--violet), var(--cyan)); box-shadow: 0 0 1rem var(--cyan); transform-origin: left; }
.how-card, .build-readout { padding: 1rem 1.1rem; }
.how-card h2, .build-readout h2 { margin: 0 0 .7rem; font-size: .88rem; }
.how-card ol { margin: 0; padding-left: 1.1rem; color: #a8bac8; font-size: .74rem; line-height: 1.55; }
.how-card li + li { margin-top: .35rem; }
.how-card p { margin: .75rem 0 0; color: #8094a4; font-size: .7rem; line-height: 1.5; }

.toast { position: absolute; left: 50%; top: 1rem; z-index: 5; max-width: 80%; padding: .65rem 1rem; pointer-events: none; border: 1px solid rgba(108,246,255,.28); border-radius: 2rem; background: rgba(5,11,19,.86); color: var(--cyan); font-size: .8rem; font-weight: 700; opacity: 0; transform: translate(-50%, -.6rem); transition: opacity .18s ease, transform .18s ease; }
.toast.show { opacity: 1; transform: translate(-50%, 0); }
.pause-badge { position: absolute; inset: 50% auto auto 50%; z-index: 6; padding: 1rem 1.4rem; border: 1px solid var(--gold); border-radius: 1rem; background: rgba(5,11,19,.94); color: var(--gold); font-weight: 800; transform: translate(-50%, -50%); }

.variant-panel, .long-panel, .social-panel, .choice-panel { margin-top: 1rem; border: 1px solid var(--line); border-radius: 1rem; background: rgba(10,20,35,.72); }
.variant-panel { display: flex; gap: .75rem; padding: 1rem 1.2rem; color: #9fb1c0; font-size: .8rem; line-height: 1.5; }
.variant-panel b { color: var(--ink); white-space: nowrap; }

.long-panel { display: grid; grid-template-columns: 15rem 1fr auto; gap: 1rem; align-items: center; padding: 1rem 1.2rem; }
.long-panel > div:first-child { display: grid; gap: .15rem; }
.long-panel strong { font-size: 1rem; }
.chapter-track { display: grid; grid-template-columns: repeat(5, 1fr); gap: .35rem; }
.chapter-track i { height: .5rem; border-radius: 2rem; background: rgba(255,255,255,.08); }
.chapter-track i.active { background: var(--gold); box-shadow: 0 0 1rem rgba(255,231,132,.55); }

.choice-panel { position: relative; padding: 1.25rem; border-color: rgba(255,111,145,.36); }
.choice-heading { display: flex; align-items: baseline; gap: 1rem; margin-bottom: 1rem; }
.choice-heading span { color: var(--pink); font-size: .7rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
.choice-heading h2 { margin: 0; font-size: 1rem; }
.choice-options { display: grid; grid-template-columns: repeat(3, 1fr); gap: .7rem; }
.choice-button { min-height: 7rem; padding: 1rem; cursor: pointer; text-align: left; border: 1px solid var(--line); border-radius: .85rem; background: #0b1928; }
.choice-button:hover, .choice-button:focus-visible { border-color: var(--choice-color, var(--cyan)); outline: none; transform: translateY(-2px); }
.choice-button span { display: block; margin-bottom: .45rem; color: var(--choice-color, var(--cyan)); font-size: .65rem; font-weight: 800; letter-spacing: .1em; text-transform: uppercase; }
.choice-button strong { display: block; margin-bottom: .35rem; font-size: .92rem; }
.choice-button small { color: #899eae; line-height: 1.45; }

.build-readout .axis { display: grid; grid-template-columns: 3.3rem 1fr 1.4rem; gap: .45rem; align-items: center; margin: .55rem 0; color: #9dafbc; font-size: .67rem; }
.build-readout .axis i { height: .34rem; border-radius: 1rem; background: rgba(255,255,255,.07); box-shadow: inset 0 0 0 1px var(--axis-color, transparent); }
.build-readout .axis i::after { content: ""; display: block; width: var(--axis-level, 0%); height: 100%; border-radius: inherit; background: var(--axis-color, var(--cyan)); }
#axis-trajectory { --axis-color: var(--cyan); } #axis-interference { --axis-color: var(--pink); } #axis-charge { --axis-color: var(--gold); }
.build-readout ul { max-height: 8.2rem; margin: .8rem 0 0; padding: .7rem 0 0 1rem; overflow: auto; border-top: 1px solid var(--line); color: #8397a6; font-size: .68rem; line-height: 1.5; }

.social-panel { display: grid; grid-template-columns: 13rem 1fr 1.5fr; gap: 1rem; align-items: center; padding: 1rem 1.2rem; }
.room-block { display: grid; grid-template-columns: 1fr auto; gap: .2rem .6rem; align-items: center; }
.room-block span { grid-column: 1 / -1; }
.room-block strong { overflow: hidden; color: var(--violet); font-size: .9rem; text-overflow: ellipsis; }
.room-block .utility-btn { min-height: 2rem; padding: .4rem .55rem; font-size: .65rem; }
.peer-block { display: grid; grid-template-columns: .7rem 1fr; gap: .7rem; align-items: center; }
.peer-block i { width: .65rem; aspect-ratio: 1; border-radius: 50%; background: #596b79; }
.peer-block i.online { background: var(--lime); box-shadow: 0 0 1rem var(--lime); }
.peer-block div { display: grid; gap: .1rem; }
.signal-buttons { display: flex; gap: .45rem; justify-content: flex-end; }
.signal-buttons button { flex: 1; min-height: 3rem; padding: .55rem; cursor: pointer; border: 1px solid var(--line); border-radius: .65rem; background: #101e2e; font-size: .68rem; }
.signal-buttons button:hover, .signal-buttons button:focus-visible { border-color: var(--violet); outline: none; }

.machine-state { position: fixed; width: 1px; height: 1px; padding: 0; overflow: hidden; clip: rect(0 0 0 0); clip-path: inset(50%); white-space: pre; }

@media (max-width: 980px) {
  .hub-hero { grid-template-columns: 1fr; gap: 2rem; }
  .hero-orbit { opacity: .55; }
  .game-header { grid-template-columns: 1fr auto; }
  .game-header .back-link { grid-column: 1 / -1; }
  .game-layout { grid-template-columns: 1fr; }
  .side-rail { grid-template-columns: repeat(4, minmax(0,1fr)); }
  .how-card, .build-readout { grid-column: span 2; }
  .social-panel { grid-template-columns: 1fr 1fr; }
  .signal-buttons { grid-column: 1 / -1; }
}

@media (max-width: 680px) {
  .hub-page { padding: .8rem; }
  .hub-hero { min-height: 30rem; padding: 1.6rem; }
  .hub-hero h1 { font-size: clamp(3rem, 16vw, 5rem); }
  .quick-rule, .build-grid { grid-template-columns: 1fr; }
  .quick-rule div { min-height: 5rem; }
  .build-card.full { grid-column: auto; }
  .hub-footer { flex-direction: column; }
  .game-page { padding: .5rem; }
  .game-header { gap: .6rem; }
  .game-header h1 { font-size: 1.35rem; }
  .utility-btn { padding: .55rem .65rem; font-size: .72rem; }
  .side-rail { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .how-card, .build-readout { grid-column: 1 / -1; }
  .choice-options { grid-template-columns: 1fr; }
  .choice-heading, .variant-panel { align-items: flex-start; flex-direction: column; }
  .long-panel { grid-template-columns: 1fr; }
  .social-panel { grid-template-columns: 1fr; }
  .signal-buttons { grid-column: auto; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
}