:root {
  --green: #25d366;
  --green-dark: #128c7e;
  --green-deep: #075e54;
  --ink: #0f1f1a;
  --muted: #5a6b64;
  --line: #d9e6e1;
  --bg: #f3faf6;
  --card: #ffffff;
  --warn-bg: #fff8e8;
  --warn-border: #f0c14b;
  --warn-text: #6b4e00;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(7, 94, 84, 0.08);
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(1200px 500px at 10% -10%, rgba(37, 211, 102, 0.18), transparent 60%),
    radial-gradient(900px 420px at 100% 0%, rgba(18, 140, 126, 0.12), transparent 55%),
    linear-gradient(180deg, #eef9f3 0%, var(--bg) 28%, #f7fbf9 100%);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--green-dark);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  width: min(1080px, calc(100% - 32px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  background: rgba(247, 251, 249, 0.9);
  border-bottom: 1px solid rgba(18, 140, 126, 0.12);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
  font-weight: 800;
  font-size: 1.15rem;
  letter-spacing: 0.02em;
}

.brand img {
  width: 40px;
  height: 40px;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  font-size: 0.92rem;
}

.nav-links a {
  color: var(--muted);
  font-weight: 600;
}

.notice {
  margin: 16px 0 0;
  padding: 14px 16px;
  background: var(--warn-bg);
  border: 1px solid var(--warn-border);
  border-radius: var(--radius);
  color: var(--warn-text);
  font-size: 0.92rem;
  font-weight: 800;
  line-height: 1.65;
}

.notice strong {
  font-weight: 900;
}

.hero {
  padding: 28px 0 18px;
  text-align: center;
}

.hero-logo {
  width: 88px;
  height: 88px;
  margin: 0 auto 14px;
  filter: drop-shadow(0 12px 24px rgba(18, 140, 126, 0.25));
  animation: floaty 4s ease-in-out infinite;
}

.hero h1 {
  margin: 0 0 10px;
  font-size: clamp(1.8rem, 5vw, 2.6rem);
  line-height: 1.25;
  letter-spacing: -0.02em;
}

.hero .lead {
  margin: 0 auto 22px;
  max-width: 640px;
  color: var(--muted);
  font-size: 1.02rem;
}

.download-box {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow: var(--shadow);
  padding: 20px 18px 18px;
  margin: 0 auto 28px;
  max-width: 720px;
}

.download-box .notice {
  margin-top: 0;
  margin-bottom: 16px;
  text-align: left;
}

.btn-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 52px;
  padding: 12px 16px;
  border-radius: 14px;
  font-weight: 800;
  font-size: 1rem;
  text-decoration: none !important;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease;
}

.btn img {
  width: 22px;
  height: 22px;
}

.btn-android {
  background: linear-gradient(135deg, #25d366, #1ebe57);
  color: #fff;
  box-shadow: 0 10px 22px rgba(37, 211, 102, 0.35);
}

.btn-ios {
  background: linear-gradient(135deg, #1c1c1c, #333);
  color: #fff;
  box-shadow: 0 10px 22px rgba(0, 0, 0, 0.22);
}

.btn:hover {
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

.section {
  padding: 10px 0 28px;
}

.section h2 {
  margin: 0 0 10px;
  font-size: 1.45rem;
}

.section p {
  margin: 0 0 12px;
  color: var(--muted);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-top: 16px;
}

.feature {
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 16px;
}

.feature h3 {
  margin: 0 0 6px;
  font-size: 1.05rem;
}

.feature h3 a {
  color: var(--ink);
  text-decoration: none;
}

.feature h3 a:hover {
  color: var(--green-dark);
  text-decoration: underline;
}

.feature p {
  margin: 0;
  font-size: 0.92rem;
}

.keyword-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 12px;
}

.keyword-cloud a {
  display: inline-block;
  padding: 7px 12px;
  border-radius: 999px;
  background: rgba(37, 211, 102, 0.1);
  color: var(--green-deep);
  font-size: 0.86rem;
  font-weight: 700;
  text-decoration: none;
}

.keyword-cloud a:hover {
  background: rgba(37, 211, 102, 0.2);
}

.content-card {
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 20px 18px;
  box-shadow: var(--shadow);
}

.content-card h2,
.content-card h3 {
  color: var(--green-deep);
}

.content-card ul {
  margin: 0 0 14px;
  padding-left: 1.2em;
  color: var(--muted);
}

.site-footer {
  margin-top: 20px;
  padding: 28px 0 110px;
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, transparent, rgba(18, 140, 126, 0.06));
}

.footer-disclaimer {
  background: #fff;
  border: 2px solid #f0c14b;
  border-radius: 14px;
  padding: 14px 16px;
  font-weight: 800;
  color: #6b4e00;
  text-align: center;
  margin-bottom: 14px;
  font-size: 0.98rem;
}

.footer-stats {
  text-align: center;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--muted);
  margin: 10px 0 0;
  letter-spacing: 0.02em;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 14px;
  margin-bottom: 12px;
  font-size: 0.88rem;
}

.footer-copy {
  text-align: center;
  color: var(--muted);
  font-size: 0.84rem;
}

.float-bar {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 80;
  padding: 10px 12px calc(10px + env(safe-area-inset-bottom));
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(10px);
  border-top: 1px solid var(--line);
  box-shadow: 0 -8px 24px rgba(0, 0, 0, 0.08);
  transform: translateY(110%);
  transition: transform 0.28s ease;
}

.float-bar.show {
  transform: translateY(0);
}

.float-bar .btn-row {
  width: min(720px, 100%);
  margin: 0 auto;
}

.breadcrumb {
  padding: 14px 0 0;
  font-size: 0.86rem;
  color: var(--muted);
}

.breadcrumb a {
  color: var(--green-dark);
}

@keyframes floaty {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-6px);
  }
}

@media (max-width: 640px) {
  .nav-links {
    display: none;
  }

  .btn-row {
    grid-template-columns: 1fr;
  }

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

  .hero {
    padding-top: 18px;
  }

  .hero-logo {
    width: 72px;
    height: 72px;
  }
}

@media (min-width: 900px) {
  .feature-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}