/* 野鳥觀察助手官网宣传页样式（v2.0.x 替换照片墙）
   纯手写静态站，无构建链；配色与排版遵循设计稿：森林绿 + 天空蓝、留白克制、响应式。 */

:root {
  --green: #2E7D32;
  --green-d: #1B5E20;
  --blue: #1565C0;
  --blue-d: #0D47A1;
  --bg: #FFFFFF;
  --bg2: #F4F7F2;
  --ink: #1A1A1A;
  --ink2: #5A5A5A;
  --line: #E3EAE0;
  --card-shadow: 0 10px 30px rgba(27, 94, 32, 0.08);
  --font: "思源黑体", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  width: min(1120px, 92vw);
  margin: 0 auto;
}

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

/* ---------- 顶部品牌栏（玻璃拟态） ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.brand {
  font-size: 20px;
  font-weight: 700;
  color: var(--green-d);
  display: flex;
  align-items: baseline;
  gap: 8px;
}
.header-inner nav { display: flex; gap: 26px; }
.header-inner nav a {
  font-size: 15px;
  color: var(--ink2);
  transition: color .2s;
}
.header-inner nav a:hover { color: var(--green); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, #EAF3E6 0%, #EAF1F8 55%, #FFFFFF 100%);
}
/* 同心圆氛围纹理（呼应设计稿） */
.hero-bg {
  position: absolute;
  right: -12%;
  top: -20%;
  width: 720px;
  height: 720px;
  border-radius: 50%;
  background:
    repeating-radial-gradient(circle at center,
      rgba(46, 125, 50, 0.08) 0 1px,
      transparent 1px 26px);
  opacity: .9;
  pointer-events: none;
}
.hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: center;
  gap: 48px;
  padding: 84px 0 96px;
}
.hero-copy h1 {
  font-size: 52px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--green-d);
  line-height: 1.1;
}
.tagline {
  margin-top: 18px;
  font-size: 22px;
  font-weight: 600;
  color: var(--ink);
}
.cta {
  margin-top: 34px;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: center;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 16px;
  font-weight: 600;
  padding: 13px 26px;
  border-radius: 999px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform .18s ease, box-shadow .18s ease, background .18s;
}
.btn-primary {
  background: linear-gradient(135deg, var(--green), var(--green-d));
  color: #fff;
  box-shadow: 0 8px 20px rgba(46, 125, 50, 0.28);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 26px rgba(46,125,50,.36); }
.btn-ghost {
  background: #fff;
  color: var(--ink);
  border-color: var(--line);
  box-shadow: var(--card-shadow);
}
.btn-ghost:hover { transform: translateY(-2px); }
.btn svg { width: 20px; height: 20px; }
.hint { margin-top: 16px; font-size: 14px; color: var(--ink2); }

/* ---------- 手机样机（内屏放小程序真实截图切图） ---------- */
.phone {
  width: 268px;
  height: 548px;
  margin: 0 auto;
  background: #0f1115;
  border-radius: 40px;
  padding: 12px;
  box-shadow: 0 30px 60px rgba(13, 71, 161, 0.18), 0 4px 12px rgba(0,0,0,.12);
  position: relative;
}
.screen {
  width: 100%; height: 100%;
  background: #fff;
  border-radius: 30px;
  overflow: hidden;
  position: relative;
}
/* 截图已按内屏比例预处理（488×1048），此处只负责铺满；object-position 保住顶部标题行 */
.screen .shot { width: 100%; height: 100%; object-fit: cover; object-position: top center; display: block; }

/* ---------- 功能卡片 ---------- */
.section-title {
  text-align: center;
  font-size: 32px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 40px;
}
.features { padding: 88px 0; background: var(--bg); }
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}
.card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 30px 26px;
  box-shadow: var(--card-shadow);
  transition: transform .2s ease, box-shadow .2s ease;
}
.card:hover { transform: translateY(-6px); box-shadow: 0 18px 40px rgba(27,94,32,.14); }
.card .ico {
  width: 54px; height: 54px; border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #EAF3E6, #E3EEF8);
  margin-bottom: 18px;
}
.card .ico svg { width: 30px; height: 30px; }
.card h3 { font-size: 20px; font-weight: 600; margin-bottom: 10px; }
.card p { font-size: 15px; color: var(--ink2); }

/* ---------- 展示区（文字 + 手机） ---------- */
.showcase { padding: 40px 0 90px; background: var(--bg2); }
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: 56px;
  padding: 36px 0;
}
.split.reverse .showcase-copy { order: 2; }
.showcase-copy h2 { font-size: 28px; font-weight: 700; color: var(--green-d); margin-bottom: 16px; }
.showcase-copy p { font-size: 16px; color: var(--ink2); }

/* ---------- 鸟图画廊 ---------- */
.gallery { padding: 88px 0; background: var(--bg); }
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.gallery figure {
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--card-shadow);
  background: #fff;
  transition: transform .2s ease, box-shadow .2s ease;
}
.gallery figure:hover { transform: translateY(-6px); box-shadow: 0 18px 40px rgba(13,71,161,.14); }
.gallery img { width: 100%; height: 220px; object-fit: cover; display: block; }
.gallery figcaption { padding: 14px 16px; }
.gallery figcaption b { font-size: 16px; }
.gallery figcaption .latin { display: block; font-size: 12px; font-style: italic; color: var(--ink2); }

/* ---------- 页脚 ---------- */
.site-footer { padding: 72px 0 48px; background: linear-gradient(180deg, #F4F7F2, #EAF1F8); }
.footer-grid { display: grid; grid-template-columns: 1fr; gap: 48px; align-items: start; }
.follow-copy h2 { font-size: 24px; font-weight: 700; color: var(--green-d); margin-bottom: 12px; }
.follow-copy p { font-size: 15px; color: var(--ink2); margin-bottom: 8px; }
.follow-copy .copyright a { color: var(--ink2); text-decoration: underline; }
.gongan-beian a { display: inline-flex; align-items: center; gap: 4px; }
.gongan-beian img { display: block; }
.attribution {
  margin-top: 18px;
  font-size: 12px !important;
  line-height: 1.7;
  color: #8a8a8a !important;
  border-top: 1px solid var(--line);
  padding-top: 16px;
}

/* ---------- 二维码弹层 ---------- */
.qr-modal {
  position: fixed; inset: 0;
  background: rgba(15, 17, 21, 0.55);
  display: none;
  align-items: center; justify-content: center;
  z-index: 100;
}
.qr-modal.open { display: flex; }
.qr-modal-box {
  background: #fff; border-radius: 18px; padding: 28px;
  text-align: center; max-width: 320px;
}
.qr-modal-box img { width: 220px; height: auto; border-radius: 10px; }
.qr-modal-box p { font-size: 14px; color: var(--ink2); margin: 14px 0 18px; }
.qr-modal-box button {
  border: none; background: var(--green); color: #fff;
  padding: 10px 24px; border-radius: 999px; font-size: 15px; cursor: pointer;
}

/* ---------- 响应式 ---------- */
@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; gap: 40px; padding: 56px 0 64px; text-align: center; }
  .hero-copy h1 { font-size: 40px; }
  .cta { justify-content: center; }
  .split, .cards, .gallery-grid { grid-template-columns: 1fr; }
  .split.reverse .showcase-copy { order: 0; }
  .gallery-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; justify-items: center; text-align: center; }
  .showcase-copy { text-align: center; }
}
@media (max-width: 520px) {
  .gallery-grid { grid-template-columns: 1fr; }
  .header-inner nav { gap: 16px; }
}