:root {
  --bg: #f4f7f1;
  --surface: #ffffff;
  --surface-muted: #f1f5ed;
  --ink: #1b2a28;
  --ink-soft: #4a5b56;
  --accent: #2f7d65;
  --accent-dark: #205848;
  --accent-warm: #b87b43;
  --border: rgba(20, 45, 38, 0.12);
  --shadow: 0 24px 60px rgba(20, 45, 38, 0.14);
  --shadow-soft: 0 14px 34px rgba(20, 45, 38, 0.1);
  --radius-lg: 26px;
  --radius-md: 18px;
  --radius-sm: 12px;
  --font-sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-serif: "Noto Serif SC", "Songti SC", "STSong", serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: var(--font-sans);
  background: var(--bg);
}

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

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

.page {
  position: relative;
  overflow: hidden;
  min-height: 100vh;
  background-image: url("bg.jpg");
  background-size: cover;
  background-position: center top;
  background-attachment: fixed;
}

.page::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(244, 247, 241, 0.55) 0%,
    rgba(244, 247, 241, 0.82) 46%,
    rgba(244, 247, 241, 0.96) 100%
  );
  z-index: 0;
}

.site-header {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 26px 7vw 8px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand img {
  width: 42px;
  height: 48px;
  object-fit: contain;
}

.brand-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

main {
  position: relative;
  z-index: 1;
  padding: 0 7vw 64px;
}

.hero {
  display: flex;
  justify-content: center;
  text-align: center;
  margin-top: 46px;
}

.hero-text {
  max-width: 720px;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.22em;
  font-size: 0.72rem;
  color: var(--accent-warm);
  margin: 0 0 16px;
}

.hero-text h1 {
  font-family: var(--font-serif);
  font-size: clamp(2.3rem, 4.6vw, 3.5rem);
  line-height: 1.32;
  margin: 0 0 22px;
  letter-spacing: 0.02em;
}

.lead {
  color: var(--ink-soft);
  font-size: 1.05rem;
  line-height: 1.95;
  margin: 0 auto 30px;
  max-width: 640px;
  text-wrap: pretty;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: center;
}

.section {
  margin-top: 76px;
  max-width: 940px;
  margin-left: auto;
  margin-right: auto;
}

.section-title {
  text-align: center;
  margin-bottom: 30px;
}

.section-title h2 {
  font-family: var(--font-serif);
  margin: 0;
  font-size: clamp(1.7rem, 2.6vw, 2.2rem);
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.download-card {
  display: flex;
  gap: 22px;
  align-items: center;
  padding: 24px;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: blur(4px);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-soft);
}

.download-card.is-disabled {
  background: rgba(241, 245, 237, 0.82);
}

.qr-wrap {
  position: relative;
  flex-shrink: 0;
  width: 138px;
  height: 138px;
  padding: 9px;
  background: #fff;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(20, 45, 38, 0.14);
}

.qr-wrap img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.qr-wrap.is-empty {
  display: flex;
  align-items: center;
  justify-content: center;
  background:
    linear-gradient(135deg, rgba(20, 45, 38, 0.07) 25%, transparent 25%) 0 0 / 13px 13px,
    linear-gradient(135deg, transparent 75%, rgba(20, 45, 38, 0.07) 75%) 0 0 / 13px 13px,
    #f4f7f1;
}

.badge {
  background: var(--accent-warm);
  color: #fff;
  font-size: 0.78rem;
  padding: 6px 12px;
  border-radius: 999px;
  box-shadow: 0 10px 20px rgba(184, 123, 67, 0.28);
}

.download-info h3 {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-size: 1.25rem;
}

.download-info p {
  margin: 0 0 16px;
  color: var(--ink-soft);
  line-height: 1.7;
  font-size: 0.95rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: var(--font-sans);
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.btn-sm {
  padding: 9px 18px;
  font-size: 0.9rem;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 14px 26px rgba(47, 125, 101, 0.28);
}

.btn-primary:hover {
  transform: translateY(-1px);
  background: var(--accent-dark);
}

.btn-muted {
  background: rgba(27, 42, 40, 0.08);
  color: var(--ink-soft);
}

.btn[aria-disabled="true"] {
  cursor: not-allowed;
  pointer-events: none;
}

.site-footer {
  position: relative;
  z-index: 1;
  padding: 32px 7vw 48px;
  color: var(--ink-soft);
  text-align: center;
  font-size: 0.9rem;
}

[data-animate] {
  opacity: 0;
  transform: translateY(16px);
  animation: fadeUp 0.8s ease forwards;
}

.download-grid [data-animate]:nth-child(2) {
  animation-delay: 0.15s;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 760px) {
  .site-header {
    padding: 22px 7vw 0;
  }

  .hero {
    margin-top: 32px;
  }

  .download-grid {
    grid-template-columns: 1fr;
  }

  .download-card {
    flex-direction: column;
    text-align: center;
    align-items: center;
  }

  .download-info .btn {
    width: 100%;
  }

  .page {
    background-attachment: scroll;
  }
}

@media (prefers-reduced-motion: reduce) {
  [data-animate] {
    animation: none;
    opacity: 1;
    transform: none;
  }
}