:root {
  --ink: #0c1210;
  --ink-soft: #16201c;
  --jade: #3a8f74;
  --jade-deep: #246853;
  --mist: #b7cfc4;
  --fog: rgba(183, 207, 196, 0.14);
  --paper: #e7f0eb;
  --gold: #d2b277;
  --text: #e8f2ec;
  --muted: rgba(232, 242, 236, 0.72);
  --max: 68rem;
  --font-display: "Noto Serif SC", "Songti SC", serif;
  --font-body: "Sora", "Noto Sans SC", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.6;
  background:
    radial-gradient(1200px 600px at 70% -10%, rgba(58, 143, 116, 0.28), transparent 55%),
    radial-gradient(900px 500px at 10% 20%, rgba(210, 178, 119, 0.12), transparent 50%),
    linear-gradient(165deg, var(--ink) 0%, var(--ink-soft) 45%, #0a100e 100%);
  background-attachment: fixed;
}

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

img {
  max-width: 100%;
  display: block;
}

.wrap {
  width: min(100% - 2.5rem, var(--max));
  margin-inline: auto;
}

/* ----- top bar ----- */
.top {
  position: absolute;
  inset: 0 0 auto;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 0;
}

.lang {
  display: flex;
  gap: 0.75rem;
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.lang a[aria-current="page"] {
  color: var(--paper);
  text-decoration: none;
  font-weight: 600;
}

.lang a:not([aria-current="page"]):hover {
  color: var(--paper);
}

/* ----- hero: one composition ----- */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  display: grid;
  align-items: end;
  overflow: hidden;
}

.hero-media {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 30%;
  transform: scale(1.04);
  animation: hero-drift 18s ease-in-out infinite alternate;
}

.hero-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(12, 18, 16, 0.35) 0%, rgba(12, 18, 16, 0.55) 42%, rgba(12, 18, 16, 0.92) 78%, var(--ink) 100%),
    linear-gradient(90deg, rgba(12, 18, 16, 0.55) 0%, transparent 45%);
}

.hero-copy {
  position: relative;
  z-index: 1;
  padding: 0 0 4.5rem;
  max-width: 38rem;
  animation: rise 0.9s ease-out both;
}

.brand {
  margin: 0 0 1.1rem;
  font-family: var(--font-display);
  font-size: clamp(3.4rem, 9vw, 5.6rem);
  font-weight: 600;
  letter-spacing: 0.08em;
  line-height: 1.05;
  color: var(--paper);
  text-shadow: 0 0.4rem 2rem rgba(0, 0, 0, 0.35);
}

.brand span {
  display: block;
  margin-top: 0.35rem;
  font-family: var(--font-body);
  font-size: 0.34em;
  font-weight: 500;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--mist);
}

.lede {
  margin: 0 0 1.75rem;
  font-size: clamp(1.05rem, 2.2vw, 1.25rem);
  color: var(--muted);
  max-width: 28rem;
}

.cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem 1rem;
}

.ph-badge {
  display: inline-block;
  margin-top: 1.25rem;
  line-height: 0;
}

.ph-badge img {
  display: block;
  width: 250px;
  max-width: 100%;
  height: auto;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.85rem;
  padding: 0.7rem 1.25rem;
  border-radius: 0.35rem;
  border: 1px solid transparent;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-decoration: none;
  transition: transform 0.2s ease, background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--jade);
  color: #f4fff9;
}

.btn-primary:hover {
  background: var(--jade-deep);
}

.btn-ghost {
  border-color: rgba(183, 207, 196, 0.45);
  color: var(--paper);
  background: rgba(12, 18, 16, 0.25);
  backdrop-filter: blur(6px);
}

.btn-ghost:hover {
  border-color: var(--mist);
  background: rgba(58, 143, 116, 0.18);
}

/* ----- sections ----- */
.section,
.start {
  padding-block: 5rem 1rem;
}

.section h2,
.start h2 {
  margin: 0 0 0.75rem;
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3.5vw, 2.25rem);
  font-weight: 600;
  letter-spacing: 0.04em;
}

.section .support,
.start .support {
  margin: 0 0 2.25rem;
  max-width: 36rem;
  color: var(--muted);
  font-size: 1.05rem;
}

.feature-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1.5rem;
}

.feature-list li {
  padding-top: 1.25rem;
  border-top: 1px solid rgba(183, 207, 196, 0.22);
  animation: rise 0.8s ease-out both;
}

.feature-list li:nth-child(2) { animation-delay: 0.08s; }
.feature-list li:nth-child(3) { animation-delay: 0.16s; }
.feature-list li:nth-child(4) { animation-delay: 0.24s; }

.feature-list h3 {
  margin: 0 0 0.4rem;
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--paper);
}

.feature-list p {
  margin: 0;
  color: var(--muted);
  max-width: 40rem;
}

.start {
  /* 只用 margin-top，避免 margin 简写盖掉 .wrap 的 margin-inline: auto */
  margin-top: 4.5rem;
  padding-top: 2.25rem;
  padding-bottom: 5rem;
  border-top: 1px solid rgba(183, 207, 196, 0.22);
}

.start pre {
  margin: 1.25rem 0 1.5rem;
  padding: 1.1rem 1.2rem;
  overflow-x: auto;
  border-radius: 0.4rem;
  background: rgba(8, 12, 10, 0.72);
  border: 1px solid rgba(183, 207, 196, 0.18);
  color: var(--mist);
  font-size: 0.92rem;
  line-height: 1.55;
}

.foot {
  padding: 1.5rem 0 2.5rem;
  border-top: 1px solid rgba(183, 207, 196, 0.16);
  color: var(--muted);
  font-size: 0.9rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
  justify-content: space-between;
}

.foot a {
  color: var(--mist);
}

@keyframes hero-drift {
  from { transform: scale(1.04) translate3d(0, 0, 0); }
  to { transform: scale(1.08) translate3d(-1.2%, -1%, 0); }
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(1rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .hero-media img,
  .hero-copy,
  .feature-list li {
    animation: none;
  }
}

@media (max-width: 640px) {
  .wrap {
    width: min(100% - 1.5rem, var(--max));
  }

  .hero-copy {
    padding-bottom: 3.25rem;
  }

  .brand {
    letter-spacing: 0.06em;
  }

  .cta {
    flex-direction: column;
    align-items: stretch;
  }
}