/* 旅行牛牛项目主页 —— 旅行青蛙式暖绿手作风 */
:root {
  --bg: #f6f3e8;          /* 米白宣纸底 */
  --ink: #33422f;         /* 墨绿文字 */
  --muted: #7a8a72;
  --green: #6fae52;       /* 草地绿 */
  --green-deep: #4c8a3c;
  --green-dark: #35682b;
  --sun: #f3c74f;         /* 旅行蛙黄 */
  --wood: #a5836a;        /* 木牌棕 */
  --card: #ffffff;
  --line: #e3ddc9;
  --radius: 20px;
  --shadow: 0 6px 24px rgba(84, 110, 72, 0.12);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  background:
    radial-gradient(circle at 12% 8%, rgba(111, 174, 82, 0.10), transparent 34%),
    radial-gradient(circle at 88% 22%, rgba(243, 199, 79, 0.12), transparent 30%),
    var(--bg);
  color: var(--ink);
  line-height: 1.7;
}

/* ===== 顶部导航 ===== */
.nav {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px clamp(16px, 5vw, 48px);
  background: rgba(246, 243, 232, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}

.brand {
  font-size: 20px; font-weight: 800; color: var(--green-dark);
  text-decoration: none; letter-spacing: 0.5px;
  display: inline-flex; align-items: center; gap: 9px;
}
.brand em { font-style: normal; font-size: 14px; color: var(--wood); margin-left: 2px; }
.brand-logo {
  display: block; width: 36px; height: 36px; object-fit: cover;
  border-radius: 10px; background: #fff;
  box-shadow: 0 2px 8px rgba(84, 110, 72, 0.25);
}

.nav-links { display: flex; align-items: center; gap: clamp(10px, 2.4vw, 22px); }
.nav-links a { color: var(--muted); text-decoration: none; font-size: 14.5px; }
.nav-links a:hover { color: var(--green-deep); }
.nav-cta {
  background: var(--green); color: #fff !important;
  padding: 7px 16px; border-radius: 999px; font-weight: 600;
  box-shadow: 0 3px 10px rgba(111, 174, 82, 0.35);
}

/* ===== Hero ===== */
.hero {
  max-width: 1080px; margin: 0 auto;
  padding: clamp(40px, 7vw, 84px) clamp(16px, 5vw, 48px) clamp(28px, 5vw, 56px);
  display: flex; align-items: center; gap: clamp(20px, 5vw, 64px);
}
.hero-text { flex: 1.2; }
.hero-art {
  flex: 1; max-width: 430px; width: 100%; height: auto;
  border-radius: 24px;
  box-shadow: 0 18px 40px rgba(84, 110, 72, 0.28);
  border: 6px solid #fff;
  animation: float 5s ease-in-out infinite;
}
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

.hero-badge {
  display: inline-block;
  background: #eaf3e0; color: var(--green-deep);
  border: 1px dashed var(--green);
  border-radius: 999px; padding: 4px 14px;
  font-size: 13.5px; font-weight: 600;
}

.hero h1 {
  font-size: clamp(34px, 6vw, 58px); line-height: 1.25;
  letter-spacing: 1px; margin: 18px 0 14px;
  color: var(--green-dark);
}

.hero-sub { color: var(--muted); font-size: clamp(15px, 1.8vw, 17.5px); margin-bottom: 26px; }

.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; }

.btn {
  display: inline-flex; align-items: center; gap: 9px;
  border-radius: 999px; text-decoration: none; font-weight: 700;
  padding: 13px 28px; font-size: 16px;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary {
  background: linear-gradient(135deg, var(--green) 0%, var(--green-deep) 100%);
  color: #fff;
  box-shadow: 0 8px 22px rgba(111, 174, 82, 0.45);
}
.btn-ghost {
  border: 2px solid var(--green); color: var(--green-deep);
  background: rgba(255, 255, 255, 0.6);
}
.btn-big { padding: 16px 40px; font-size: 18px; margin-top: 20px; }

.platform-note {
  margin-top: 16px; font-size: 13.5px; color: var(--muted);
}
.platform-note b { color: var(--green-deep); }

/* ===== 分区 ===== */
.section { max-width: 1080px; margin: 0 auto; padding: clamp(36px, 6vw, 72px) clamp(16px, 5vw, 48px); }
.section-alt {
  max-width: none;
  background: linear-gradient(180deg, transparent 0%, rgba(111, 174, 82, 0.08) 18%, rgba(111, 174, 82, 0.08) 82%, transparent 100%);
}
.section-title {
  text-align: center; font-size: clamp(22px, 3.4vw, 30px);
  color: var(--green-dark); margin-bottom: clamp(26px, 4vw, 44px); letter-spacing: 1px;
}
.section-title::after {
  content: "🌿"; display: block; font-size: 18px; margin-top: 6px;
}

/* 功能卡片 */
.cards {
  display: grid; gap: 20px;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
}
.card {
  background: var(--card); border-radius: var(--radius);
  padding: 26px 22px; box-shadow: var(--shadow);
  border: 1px solid rgba(227, 221, 201, 0.7);
  transition: transform 0.18s ease;
}
.card:hover { transform: translateY(-4px) rotate(-0.4deg); }
.card-icon { font-size: 34px; }
.card h3 { margin: 12px 0 8px; font-size: 17.5px; color: var(--green-dark); }
.card p { font-size: 14.5px; color: var(--muted); }

/* 三步 */
.steps {
  list-style: none; max-width: 880px; margin: 0 auto;
  display: grid; gap: 22px;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
}
.steps li {
  background: var(--card); border-radius: var(--radius);
  padding: 24px 22px; box-shadow: var(--shadow); text-align: center;
}
.step-no {
  display: inline-flex; width: 40px; height: 40px;
  align-items: center; justify-content: center;
  background: var(--sun); color: #6b5310;
  border-radius: 50%; font-weight: 800; font-size: 17px;
  box-shadow: 0 3px 8px rgba(243, 199, 79, 0.5);
}
.steps h3 { margin: 12px 0 6px; font-size: 16.5px; color: var(--green-dark); }
.steps p { font-size: 14px; color: var(--muted); }

/* 下载横幅 */
.download {
  max-width: 880px; margin: 0 auto;
  background: linear-gradient(135deg, var(--green-deep), var(--green-dark));
  border-radius: 28px; text-align: center;
  padding: clamp(36px, 5vw, 56px) 24px;
  color: #fff; box-shadow: 0 16px 40px rgba(53, 104, 43, 0.35);
}
.download-art {
  display: block; width: 96px; height: 96px; object-fit: cover;
  border-radius: 22px; background: #fff; margin: 0 auto 10px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}
.download h2 { font-size: clamp(22px, 3.4vw, 30px); margin-bottom: 8px; }
.download p { color: rgba(255, 255, 255, 0.85); font-size: 15px; }
.download .btn-primary { background: var(--sun); color: #5c4708; box-shadow: 0 8px 20px rgba(0, 0, 0, 0.22); }
.download .platform-note { color: rgba(255, 255, 255, 0.75); }

/* FAQ */
#faq details {
  max-width: 760px; margin: 0 auto 14px;
  background: var(--card); border-radius: 16px;
  border: 1px solid var(--line); padding: 0 20px;
  box-shadow: 0 2px 10px rgba(84, 110, 72, 0.06);
}
#faq summary {
  cursor: pointer; padding: 16px 0;
  font-weight: 700; color: var(--green-dark); font-size: 15.5px;
  list-style: none; position: relative;
}
#faq summary::before { content: "🌼 "; }
#faq summary::after {
  content: "＋"; position: absolute; right: 2px; top: 50%;
  transform: translateY(-50%); color: var(--wood); font-weight: 400;
}
#faq details[open] summary::after { content: "－"; }
#faq details p { padding: 0 0 16px; color: var(--muted); font-size: 14.5px; }

/* 页脚 */
.footer {
  text-align: center; padding: 34px 16px 40px;
  color: var(--muted); font-size: 13.5px;
  border-top: 1px solid var(--line); margin-top: 24px;
}
.footer a { color: var(--wood); text-decoration: none; }
.footer a:hover { color: var(--green-deep); }

/* 移动端 */
@media (max-width: 760px) {
  .nav-links a:not(.nav-cta) { display: none; }
  .hero { flex-direction: column-reverse; text-align: center; }
  .hero-art { max-width: 240px; }
  .hero-actions { justify-content: center; }
}