:root {
  color-scheme: dark;
  --bg: #050507;
  --surface: #100b0e;
  --surface-strong: #191014;
  --surface-soft: #0c090b;
  --text: #fff8ee;
  --muted: #cbbec0;
  --subtle: #95878b;
  --line: rgb(255 145 45 / 0.25);
  --line-strong: rgb(255 178 74 / 0.52);
  --ember: #ff4a1f;
  --orange: #ff9138;
  --gold: #ffc45c;
  --cyan: #23c7e8;
  --pink: #ff3d91;
  --violet: #9161ff;
  --green: #49c86a;
  --radius: 22px;
  --max: 1180px;
  --shadow: 0 26px 90px rgb(0 0 0 / 0.48);
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Segoe UI", "PingFang SC", "PingFang TC", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.6;
  overflow-x: hidden;
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  background:
    radial-gradient(circle at 8% 13%, rgb(255 54 20 / 0.17), transparent 28%),
    radial-gradient(circle at 88% 5%, rgb(255 150 53 / 0.09), transparent 24%),
    linear-gradient(180deg, #070608 0%, var(--bg) 46%, #080507 100%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: 0.25;
  background-image:
    linear-gradient(rgb(255 150 65 / 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgb(255 150 65 / 0.025) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(to bottom, black, transparent 78%);
}

a { color: inherit; text-underline-offset: 4px; }
button { font: inherit; }
img { max-width: 100%; }
p, h1, h2, strong, summary, li { overflow-wrap: break-word; }

:focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 4px;
}

.cn, .en { display: none; }
html[data-lang="zh"] .cn { display: inline; }
html[data-lang="zh"] .cn.block { display: block; }
html[data-lang="en"] .en { display: inline; }
html[data-lang="en"] .en.block { display: block; }

.shell {
  width: min(var(--max), calc(100% - 44px));
  margin: 0 auto;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid rgb(255 137 46 / 0.18);
  background: rgb(5 5 7 / 0.86);
  backdrop-filter: blur(20px) saturate(1.2);
}

.topbar-inner {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  text-decoration: none;
  font-size: 19px;
  font-weight: 900;
  letter-spacing: 0.01em;
}

.brand-icon {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  box-shadow: 0 0 0 1px rgb(255 184 70 / 0.38), 0 0 24px rgb(255 60 15 / 0.35);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: clamp(12px, 2vw, 24px);
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
}

.nav a { text-decoration: none; transition: color 160ms ease; }
.nav a:hover { color: var(--gold); }

.lang-switch {
  min-width: 84px;
  min-height: 42px;
  padding: 8px 14px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: linear-gradient(180deg, rgb(255 125 34 / 0.14), rgb(255 68 21 / 0.05));
  color: var(--text);
  font-weight: 850;
  cursor: pointer;
  transition: transform 160ms ease, border-color 160ms ease, box-shadow 160ms ease;
}

.lang-switch:hover {
  transform: translateY(-1px);
  border-color: var(--gold);
  box-shadow: 0 0 22px rgb(255 97 30 / 0.22);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(420px, 1.08fr);
  gap: clamp(42px, 6vw, 90px);
  align-items: center;
  min-height: calc(100vh - 76px);
  padding: clamp(60px, 8vw, 110px) 0;
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--orange);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(58px, 8.4vw, 110px);
  line-height: 0.88;
  letter-spacing: -0.055em;
  background: linear-gradient(115deg, #fffaf3 8%, #ffc16a 45%, #ff5a24 88%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 8px 34px rgb(255 61 18 / 0.2));
}

.hero-slogan {
  margin: 28px 0 0;
  max-width: 660px;
  color: var(--text);
  font-size: clamp(24px, 3vw, 38px);
  font-weight: 850;
  line-height: 1.17;
}

.lead {
  margin: 22px 0 0;
  max-width: 660px;
  color: var(--muted);
  font-size: clamp(17px, 1.7vw, 21px);
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}

.fire-button, .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 54px;
  padding: 0 24px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 900;
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.fire-button {
  position: relative;
  border: 1px solid #ffb34e;
  color: #160605;
  background: linear-gradient(135deg, #ffd36e, #ff8b31 52%, #ff431d);
  box-shadow: 0 0 0 5px rgb(255 78 24 / 0.11), 0 0 34px rgb(255 74 24 / 0.35), inset 0 1px 0 rgb(255 255 255 / 0.55);
}

.fire-button::before {
  content: "";
  position: absolute;
  inset: -8px;
  border: 1px dashed rgb(255 170 62 / 0.7);
  border-radius: inherit;
  animation: fire-ring 10s linear infinite;
}

.fire-button:hover, .btn:hover { transform: translateY(-2px); }
.fire-button:hover { box-shadow: 0 0 0 6px rgb(255 78 24 / 0.14), 0 0 42px rgb(255 74 24 / 0.48); }

.btn.secondary {
  border: 1px solid var(--line-strong);
  background: rgb(18 11 14 / 0.78);
  color: var(--text);
}

.hero-notes {
  display: flex;
  flex-wrap: wrap;
  gap: 26px;
  margin-top: 40px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.hero-notes > span { display: grid; grid-template-columns: auto 1fr; align-items: center; gap: 8px; }
.hero-notes strong { color: var(--gold); font-size: 24px; }
.hero-notes small { color: var(--subtle); font-size: 12px; font-weight: 750; }

.hero-visual {
  position: relative;
  isolation: isolate;
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 34px;
  background: #030304;
  box-shadow: var(--shadow), 0 0 70px rgb(255 57 18 / 0.1);
  transform: perspective(1300px) rotateY(-3deg) rotateX(1deg);
}

.hero-visual::before, .hero-visual::after {
  content: "";
  position: absolute;
  pointer-events: none;
  border-radius: 50%;
  border: 1px solid rgb(255 144 47 / 0.3);
}

.hero-visual::before { inset: 12% 18%; animation: orbit-pulse 5s ease-in-out infinite; }
.hero-visual::after { inset: 24% 30%; border-style: dashed; animation: orbit-pulse 5s ease-in-out 1s infinite reverse; }

.hero-visual img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 33px;
}

.hero-glow {
  position: absolute;
  left: 25%;
  top: 46%;
  z-index: 1;
  width: 26%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: rgb(255 64 13 / 0.18);
  filter: blur(32px);
  animation: glow-breathe 2.6s ease-in-out infinite;
}

.section {
  padding: clamp(74px, 9vw, 118px) 0;
  border-top: 1px solid rgb(255 142 48 / 0.14);
}

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(300px, 0.75fr);
  gap: 54px;
  align-items: end;
  margin-bottom: 38px;
}

.section-head h2, .final-card h2, .privacy-band h2 {
  margin: 0;
  font-size: clamp(36px, 5vw, 66px);
  line-height: 1.03;
  letter-spacing: -0.045em;
}

.section-head > p {
  margin: 0;
  color: var(--muted);
  font-size: 18px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.feature-card {
  min-height: 260px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    radial-gradient(circle at 100% 0%, rgb(255 91 26 / 0.09), transparent 38%),
    linear-gradient(145deg, rgb(24 14 18 / 0.96), rgb(10 8 9 / 0.96));
  box-shadow: inset 0 1px 0 rgb(255 255 255 / 0.025);
}

.feature-card.featured-card {
  grid-column: span 2;
  display: grid;
  grid-template-columns: 120px 1fr;
  align-items: center;
  gap: 24px;
}

.feature-card strong { display: block; margin-bottom: 10px; font-size: 23px; }
.feature-card p { margin: 0; color: var(--muted); }

.feature-icon {
  position: relative;
  display: grid;
  place-items: center;
  width: 72px;
  height: 72px;
  margin-bottom: 38px;
  border: 1px solid var(--line-strong);
  border-radius: 22px;
  background: rgb(255 78 22 / 0.08);
  color: var(--gold);
  font-size: 24px;
  font-weight: 950;
  box-shadow: 0 0 26px rgb(255 70 18 / 0.12);
}

.featured-card .feature-icon { width: 110px; height: 110px; margin: 0; border-radius: 30px; }

.tilt-icon::before {
  content: "";
  width: 58%;
  height: 34%;
  border: 4px solid var(--orange);
  border-radius: 9px;
  transform: rotate(-18deg);
  box-shadow: inset 0 0 12px rgb(255 78 22 / 0.25);
}

.tilt-icon::after {
  content: "";
  position: absolute;
  width: 18%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 10px var(--ember);
  animation: tilt-ball 2.8s ease-in-out infinite;
}

.burst-icon::before {
  content: "";
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--pink);
  box-shadow: 0 -25px 0 -11px var(--gold), 22px -12px 0 -11px var(--cyan), 22px 12px 0 -11px var(--green), 0 25px 0 -11px var(--violet), -22px 12px 0 -11px var(--orange), -22px -12px 0 -11px var(--pink);
}

.physics-icon::before, .physics-icon::after {
  content: "";
  position: absolute;
  width: 27px;
  height: 27px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, #fff1a1, #ff541e 38%, #961207 80%);
  box-shadow: 0 0 12px rgb(255 62 17 / 0.55);
}

.physics-icon::before { transform: translateX(-14px); }
.physics-icon::after { transform: translateX(14px); }

.level-track {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.level-stage {
  position: relative;
  overflow: hidden;
  min-height: 350px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, #120b0f, #080708);
}

.stage-number {
  display: inline-flex;
  padding: 5px 10px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  color: var(--gold);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.12em;
}

.stage-art {
  position: relative;
  height: 150px;
  margin: 24px -8px 18px;
  border: 1px solid rgb(255 95 29 / 0.22);
  border-radius: 18px;
  background:
    radial-gradient(circle at 24% 65%, var(--cyan) 0 5px, transparent 6px),
    radial-gradient(circle at 36% 44%, var(--pink) 0 5px, transparent 6px),
    radial-gradient(circle at 49% 66%, var(--gold) 0 5px, transparent 6px),
    radial-gradient(circle at 62% 42%, var(--green) 0 5px, transparent 6px),
    radial-gradient(circle at 75% 64%, var(--violet) 0 5px, transparent 6px),
    #050506;
}

.stage-art i {
  position: absolute;
  width: 25px;
  height: 25px;
  border: 4px solid #6d2118;
  border-radius: 50%;
  background: #000;
  box-shadow: 0 0 0 2px rgb(255 69 24 / 0.13);
}

.stage-art i:nth-child(1) { left: 17%; top: 24%; }
.stage-art i:nth-child(2) { right: 19%; top: 26%; }
.stage-art i:nth-child(3) { left: 46%; bottom: 16%; }
.stage-art i:nth-child(4) { right: 34%; bottom: 38%; }
.stage-art i:nth-child(5) { left: 28%; bottom: 34%; }

.level-stage strong { display: block; margin-bottom: 8px; font-size: 22px; }
.level-stage p { margin: 0; color: var(--muted); }

.final-section { border-top: 0; }

.final-card {
  position: relative;
  overflow: hidden;
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(290px, 0.75fr);
  gap: 54px;
  align-items: center;
  padding: clamp(34px, 6vw, 72px);
  border: 1px solid var(--line-strong);
  border-radius: 32px;
  background:
    radial-gradient(circle at 92% 8%, rgb(255 102 21 / 0.2), transparent 35%),
    radial-gradient(circle at 4% 100%, rgb(122 18 16 / 0.32), transparent 36%),
    linear-gradient(135deg, #1c0e12, #080607 70%);
  box-shadow: var(--shadow), inset 0 1px 0 rgb(255 255 255 / 0.04);
}

.final-copy > p:not(.eyebrow) { color: var(--muted); font-size: 18px; }

.checklist, .privacy-list {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 11px;
}

.checklist li, .privacy-list li {
  position: relative;
  padding-left: 28px;
  color: var(--muted);
}

.checklist li::before, .privacy-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 12px var(--ember);
}

.timer-panel {
  display: grid;
  justify-items: center;
  padding: 30px 20px;
  border: 1px solid rgb(255 179 72 / 0.42);
  border-radius: 28px;
  background: rgb(3 3 4 / 0.72);
  box-shadow: inset 0 0 40px rgb(255 58 18 / 0.06);
}

.timer-label { color: var(--subtle); font-size: 13px; font-weight: 800; letter-spacing: 0.12em; text-transform: uppercase; }
.timer-panel > strong { margin: 10px 0 18px; color: var(--text); font-size: clamp(39px, 4.5vw, 58px); line-height: 1; font-variant-numeric: tabular-nums; }

.rank-line {
  display: flex;
  justify-content: space-between;
  width: 100%;
  padding: 14px 16px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  color: var(--muted);
}

.rank-line span:first-child { color: var(--gold); font-weight: 900; }

.record-pill {
  display: flex;
  align-items: center;
  gap: 9px;
  margin-top: 20px;
  padding: 8px 13px;
  border: 1px solid rgb(255 79 44 / 0.33);
  border-radius: 999px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 750;
}

.record-dot { width: 9px; height: 9px; border-radius: 50%; background: #ff4d38; box-shadow: 0 0 10px #ff3b2f; }

.privacy-band {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(300px, 0.92fr);
  gap: 48px;
  align-items: center;
  padding: clamp(32px, 5vw, 58px);
  border: 1px solid var(--line);
  border-radius: 30px;
  background:
    radial-gradient(circle at 100% 0%, rgb(255 166 57 / 0.12), transparent 36%),
    linear-gradient(145deg, #120c0f, #090708);
}

.privacy-band p:not(.eyebrow) { color: var(--muted); font-size: 18px; }

.privacy-list { margin: 0; }
.privacy-list li { padding: 14px 16px 14px 42px; border: 1px solid var(--line); border-radius: 14px; background: rgb(4 4 5 / 0.6); }
.privacy-list li::before { left: 17px; top: 1.22em; background: var(--gold); }

.compact-head { grid-template-columns: 1fr; }

.faq { display: grid; gap: 12px; }

.faq details {
  border: 1px solid var(--line);
  border-radius: 17px;
  background: rgb(16 10 13 / 0.72);
}

.faq summary {
  position: relative;
  min-height: 62px;
  padding: 18px 54px 18px 20px;
  cursor: pointer;
  list-style: none;
  font-weight: 850;
}

.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 22px; top: 50%; color: var(--orange); font-size: 26px; transform: translateY(-50%); }
.faq details[open] summary::after { content: "−"; }
.faq details p { margin: 0; padding: 0 54px 22px 20px; color: var(--muted); }

.footer {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 24px;
  align-items: center;
  padding: 42px 0;
  border-top: 1px solid var(--line);
}

.footer strong { font-size: 21px; }
.footer p { margin: 5px 0 0; color: var(--subtle); font-size: 14px; }
.footer-links { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 20px; color: var(--muted); font-size: 14px; }
.footer-links a:hover { color: var(--gold); }
.copyright { grid-column: 1 / -1; }

@keyframes fire-ring { to { transform: rotate(360deg); } }
@keyframes orbit-pulse { 0%, 100% { opacity: 0.35; transform: scale(0.96); } 50% { opacity: 0.72; transform: scale(1.04); } }
@keyframes glow-breathe { 0%, 100% { opacity: 0.58; transform: scale(0.9); } 50% { opacity: 1; transform: scale(1.15); } }
@keyframes tilt-ball { 0%, 100% { transform: translate(-20px, 10px); } 50% { transform: translate(20px, -10px); } }

@media (max-width: 980px) {
  .hero { grid-template-columns: 1fr; min-height: auto; }
  .hero-copy { max-width: 760px; }
  .hero-visual { width: min(100%, 780px); justify-self: center; transform: none; }
  .feature-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .feature-card.featured-card { grid-column: span 2; }
  .level-track { grid-template-columns: 1fr; }
  .level-stage { min-height: 0; display: grid; grid-template-columns: minmax(200px, 0.75fr) minmax(0, 1fr); column-gap: 24px; }
  .level-stage .stage-number { align-self: start; justify-self: start; }
  .level-stage .stage-art { grid-row: 1 / span 3; margin: 0; height: 180px; }
  .level-stage strong { align-self: end; }
  .final-card { grid-template-columns: 1fr; }
  .timer-panel { width: min(100%, 480px); justify-self: center; }
}

@media (max-width: 760px) {
  .shell { width: min(100% - 28px, var(--max)); }
  .topbar { position: relative; }
  .topbar-inner { padding: 14px 0; align-items: flex-start; }
  .brand { padding-top: 2px; }
  .nav { max-width: 70%; flex-wrap: wrap; gap: 10px 15px; }
  .nav a { min-height: 36px; display: inline-flex; align-items: center; }
  .lang-switch { min-height: 40px; }
  .hero { padding: 60px 0 74px; gap: 42px; }
  h1 { font-size: clamp(54px, 17vw, 84px); }
  .hero-slogan { font-size: 26px; }
  .hero-visual { border-radius: 22px; }
  .hero-visual img { border-radius: 21px; }
  .section { padding: 72px 0; }
  .section-head { grid-template-columns: 1fr; gap: 18px; }
  .feature-grid { grid-template-columns: 1fr; }
  .feature-card.featured-card { grid-column: span 1; grid-template-columns: 1fr; }
  .featured-card .feature-icon { width: 86px; height: 86px; }
  .level-stage { display: block; }
  .level-stage .stage-art { margin: 24px -8px 18px; height: 150px; }
  .final-card, .privacy-band { grid-template-columns: 1fr; gap: 34px; }
  .footer { grid-template-columns: 1fr; }
  .footer-links { justify-content: flex-start; }
  .copyright { grid-column: auto; }
}

@media (max-width: 520px) {
  .topbar-inner { display: grid; grid-template-columns: 1fr; }
  .nav { max-width: none; justify-content: flex-start; }
  .nav a { font-size: 13px; }
  .hero-notes { gap: 16px; }
  .hero-notes > span { min-width: 110px; }
  .feature-card { min-height: 0; padding: 23px; }
  .final-card, .privacy-band { padding: 26px 22px; border-radius: 24px; }
  .timer-panel > strong { font-size: 38px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}