:root {
  color-scheme: dark;
  --ink: #f6f4e8;
  --muted: #b8c9be;
  --coral: #ff9b83;
  --line: #385c4d;
  font-family: "DM Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: #102720;
  color: var(--ink);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; }
a { color: inherit; text-decoration: none; }
:focus-visible { outline: 3px solid var(--coral); outline-offset: 5px; }
.shell { width: min(1176px, calc(100% - 104px)); margin-inline: auto; }
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: 92px;
  border-bottom: 1px solid var(--line);
}
.brand { display: inline-flex; gap: 12px; align-items: center; font-weight: 750; }
.mark {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  background: var(--coral);
  color: #231814;
  border-radius: 50%;
}
.nav-link { color: var(--muted); font-size: .9rem; }
.nav-link span { margin-left: 8px; }
.hero {
  position: relative;
  isolation: isolate;
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  gap: clamp(44px, 7vw, 108px);
  align-items: center;
  min-height: 560px;
  padding-block: 70px;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  z-index: -1;
  inset: 0 0 0 32%;
  background: repeating-radial-gradient(ellipse at 72% 56%, #608e7252 0 1px, transparent 1px 24px);
  mask-image: linear-gradient(90deg, transparent, black 45%, transparent 100%);
  opacity: .55;
}
.hero h1 {
  margin: 0;
  max-width: 11ch;
  font-size: clamp(3.15rem, 6.4vw, 6.6rem);
  line-height: 1.05;
  letter-spacing: -.055em;
  overflow-wrap: anywhere;
}
.hero-copy p { max-width: 27em; margin: 24px 0 30px; color: var(--muted); line-height: 1.85; }
.button {
  display: inline-flex;
  gap: 34px;
  min-height: 52px;
  padding: 12px 19px;
  align-items: center;
  border-radius: 999px;
  background: var(--coral);
  color: #231814;
  font-weight: 750;
}
.button:hover { background: #ffb39f; }
.hero-copy small { display: block; margin-top: 12px; color: var(--muted); overflow-wrap: anywhere; }
.guide {
  background: #18372c;
  padding: clamp(20px, 3vw, 36px);
  border: 1px solid var(--line);
  border-radius: 12px 48px 12px 12px;
  scroll-margin-top: 20px;
}
.guide h2 { margin: 0 0 20px; font-size: 1.4rem; }
.guide details { border-top: 1px solid var(--line); }
.guide summary {
  list-style: none;
  cursor: pointer;
  min-height: 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  font-weight: 700;
}
.guide summary::-webkit-details-marker { display: none; }
.guide summary::after { content: "+"; color: var(--coral); font-size: 1.3rem; }
.guide details[open] summary::after { content: "−"; }
.guide p { margin: 0 0 16px; color: var(--muted); font-size: .91rem; line-height: 1.8; }
.notice {
  display: grid;
  grid-template-columns: 9rem 1fr;
  align-items: baseline;
  gap: 12px;
  padding-block: 24px;
  border-block: 1px solid var(--line);
}
.notice h2 { margin: 0; font-size: 1rem; }
.notice p { margin: 0; color: var(--muted); font-size: .91rem; line-height: 1.8; }
.footer { display: flex; justify-content: space-between; padding-block: 26px; color: var(--muted); font-size: .8rem; }
@media (max-width: 750px) {
  .shell { width: calc(100% - 40px); }
  .topbar { min-height: 68px; }
  .hero { grid-template-columns: 1fr; min-height: auto; padding-block: 48px; gap: 36px; }
  .hero::before { inset: 0 -30% 35% 10%; }
  .notice { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}