:root {
  --brand: #2f7d6b;
  --brand-deep: #1f5549;
  --brand-soft: #d8ebe4;
  --ink: #17312b;
  --muted: #5d726c;
  --paper: #f3f7f5;
  --line: rgba(23, 49, 43, 0.12);
  --warm: #e8a23a;
  --shadow: 0 24px 60px rgba(31, 85, 73, 0.18);
  --font-display: "Noto Serif SC", "Songti SC", serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: var(--font-body);
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(47, 125, 107, 0.16), transparent 60%),
    radial-gradient(900px 500px at 100% 0%, rgba(232, 162, 58, 0.12), transparent 55%),
    linear-gradient(180deg, #eef5f2 0%, var(--paper) 42%, #e8f0ec 100%);
  min-height: 100vh;
}

a {
  color: inherit;
  text-decoration: none;
}

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

.wrap {
  width: min(1120px, calc(100% - 2.5rem));
  margin-inline: auto;
}

.site-header {
  position: absolute;
  inset: 0 0 auto;
  z-index: 5;
  padding: 1.25rem 0;
}

.site-header .wrap,
.page-top .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  color: #fff;
  text-shadow: 0 1px 10px rgba(0, 0, 0, 0.25);
}

.brand img {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.18);
}

.brand span {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.nav {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  color: rgba(255, 255, 255, 0.92);
  font-size: 0.95rem;
}

.nav a:hover {
  color: #fff;
}

.hero {
  position: relative;
  min-height: 100svh;
  display: grid;
  align-items: end;
  color: #fff;
  overflow: hidden;
  isolation: isolate;
}

.hero-media {
  position: absolute;
  inset: 0;
  z-index: -2;
}

.hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 40%;
  transform: scale(1.02);
  animation: drift 18s ease-in-out infinite alternate;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    linear-gradient(180deg, rgba(17, 42, 36, 0.28) 0%, rgba(17, 42, 36, 0.18) 35%, rgba(17, 42, 36, 0.72) 100%),
    linear-gradient(90deg, rgba(17, 42, 36, 0.45), transparent 55%);
}

.hero-content {
  width: min(720px, calc(100% - 2.5rem));
  margin: 0 auto 12vh;
  padding-top: 7rem;
  animation: rise 0.9s ease both;
}

.hero h1 {
  margin: 0 0 0.85rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.4rem, 6vw, 4.2rem);
  line-height: 1.15;
  letter-spacing: 0.02em;
}

.hero p {
  margin: 0 0 1.75rem;
  max-width: 28rem;
  font-size: 1.08rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.9);
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  align-items: center;
}

.btn {
  appearance: none;
  border: 0;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  min-height: 3rem;
  padding: 0.75rem 1.35rem;
  border-radius: 999px;
  font: inherit;
  font-weight: 600;
  transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

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

.btn-primary {
  background: #fff;
  color: var(--brand-deep);
  box-shadow: var(--shadow);
}

.btn-primary:hover {
  background: #f7fbf9;
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.14);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.35);
  backdrop-filter: blur(8px);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.22);
}

.btn[disabled] {
  opacity: 0.65;
  cursor: wait;
  transform: none;
}

.meta-line {
  margin-top: 1rem;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.78);
}

.section {
  padding: 5.5rem 0;
}

.section h2 {
  margin: 0 0 0.75rem;
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  letter-spacing: 0.02em;
}

.section .lead {
  margin: 0 0 2.5rem;
  max-width: 36rem;
  color: var(--muted);
  line-height: 1.8;
  font-size: 1.05rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.feature {
  padding: 0.25rem 0;
}

.feature h3 {
  margin: 0 0 0.55rem;
  font-size: 1.15rem;
}

.feature p {
  margin: 0;
  color: var(--muted);
  line-height: 1.75;
}

.download-panel {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 2rem;
  align-items: center;
  padding: 2rem 0;
}

.version-box {
  padding: 1.5rem 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.version-box strong {
  display: block;
  font-size: 1.35rem;
  margin-bottom: 0.35rem;
}

.version-box p {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.site-footer {
  padding: 2.5rem 0 3rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
}

.site-footer .wrap {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
}

.footer-links {
  display: flex;
  gap: 1.25rem;
}

.footer-links a:hover {
  color: var(--brand-deep);
}

/* legal pages */
.page-top {
  padding: 1.25rem 0;
  background: rgba(255, 255, 255, 0.55);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.page-top .brand {
  color: var(--brand-deep);
  text-shadow: none;
}

.page-top .nav {
  color: var(--muted);
}

.legal {
  padding: 3.5rem 0 5rem;
}

.legal-header {
  margin-bottom: 2.5rem;
  animation: rise 0.7s ease both;
}

.legal-header h1 {
  margin: 0 0 0.75rem;
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 2.8rem);
}

.legal-header p {
  margin: 0;
  color: var(--muted);
}

.legal-body {
  max-width: 46rem;
  line-height: 1.9;
  color: #243f38;
  animation: rise 0.85s ease both;
}

.legal-body h2 {
  margin: 2.2rem 0 0.7rem;
  font-size: 1.2rem;
  font-family: var(--font-display);
}

.legal-body p,
.legal-body li {
  margin: 0 0 0.9rem;
}

.legal-body ul {
  padding-left: 1.2rem;
  margin: 0 0 1rem;
}

@keyframes drift {
  from {
    transform: scale(1.02) translate3d(0, 0, 0);
  }
  to {
    transform: scale(1.06) translate3d(-1.2%, -0.8%, 0);
  }
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 860px) {
  .feature-grid,
  .download-panel {
    grid-template-columns: 1fr;
  }

  .nav {
    gap: 0.85rem;
    font-size: 0.88rem;
  }

  .hero-content {
    margin-bottom: 8vh;
  }
}

@media (prefers-reduced-motion: reduce) {
  .hero-media img,
  .hero-content,
  .legal-header,
  .legal-body {
    animation: none;
  }
}