/* 飞鸟加速器 · 候鸟·天空航线日志 —— 极简编辑设计(editorial)
   雾蓝白底 + 衬线大标题 + mono 编号 + 细线 + 天空渐变 hero + 留白 */
:root{
  --paper:#f5f8fb; --card:#ffffff;
  --ink:#1a2b3c; --muted:#64788a;
  --primary:#e8893a; --primary-2:#c96f24;
  --sky:#3e6d9c; --line:#d7e1ea; --line-soft:#e6edf3;
  --footer:#12233a;
  --serif:Georgia,"Times New Roman","Songti SC","STSong","SimSun",serif;
  --mono:"SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  background:var(--paper);color:var(--ink);line-height:1.8;font-size:16px;-webkit-font-smoothing:antialiased}
a{color:var(--primary);text-decoration:none;transition:.2s}
a:hover{color:var(--primary-2)}
img{max-width:100%;display:block}
.container{max-width:1080px;margin:0 auto;padding:0 28px}
.hl{color:var(--primary)}
::selection{background:rgba(232,137,58,.25)}

/* ===== 杂志刊头顶栏 ===== */
.nav{position:sticky;top:0;z-index:50;background:rgba(245,248,251,.92);backdrop-filter:blur(8px);
  border-bottom:1px solid var(--line)}
.nav-inner{max-width:1080px;margin:0 auto;padding:0 28px;height:64px;display:flex;align-items:center;gap:26px}
.brand{display:flex;align-items:center;gap:10px;color:var(--ink);font-family:var(--serif);font-weight:700;font-size:19px;letter-spacing:.02em}
.brand:hover{color:var(--ink)}
.brand-logo{width:30px;height:30px;border-radius:7px}
.nav-links{list-style:none;display:flex;gap:4px;margin-left:auto}
.nav-links a{display:block;padding:8px 14px;color:var(--muted);font-size:15px;font-weight:600;border-radius:8px}
.nav-links a:hover{color:var(--ink);background:var(--line-soft)}
.nav-links a.active{color:var(--primary)}
.nav-cta{padding:9px 18px;font-size:14px}
.nav-toggle{display:none;background:none;border:none;color:var(--ink);cursor:pointer;margin-left:auto;padding:6px}

/* ===== 按钮 ===== */
.btn{display:inline-flex;align-items:center;gap:8px;padding:12px 26px;border-radius:8px;font-weight:700;
  font-size:15px;border:1px solid transparent;cursor:pointer;transition:.2s}
.btn-primary{background:var(--primary);color:#fff}
.btn-primary:hover{background:var(--primary-2);color:#fff;transform:translateY(-1px)}
.btn-ghost{background:transparent;color:var(--ink);border-color:var(--line)}
.btn-ghost:hover{border-color:var(--primary);color:var(--primary)}

/* ===== hero:通栏天空渐变 ===== */
.hero{position:relative;overflow:hidden;background:linear-gradient(180deg,#0b2545 0%,#1d3f66 32%,#3e6d9c 58%,#7ba6cd 74%,#e0a962 90%,#f3d9a4 100%)}
.hero-sky{position:absolute;inset:0;pointer-events:none}
.hero-sky svg{width:100%;height:100%;display:block}
.hero-inner{position:relative;max-width:1080px;margin:0 auto;padding:96px 28px 80px;text-align:left;color:#fff}
.hero-kicker{display:inline-block;font-family:var(--mono);font-size:13px;letter-spacing:.18em;text-transform:uppercase;
  color:rgba(255,255,255,.82);border:1px solid rgba(255,255,255,.35);padding:6px 16px;border-radius:999px;margin-bottom:26px}
.hero h1{font-family:var(--serif);font-size:60px;line-height:1.12;font-weight:700;letter-spacing:.01em;margin-bottom:22px}
.hero h1 .hl{color:#f5b877}
.hero-lead{font-size:18px;color:rgba(255,255,255,.88);max-width:600px;margin-bottom:34px}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap}
.hero-actions .btn-primary{background:#fff;color:#1a2b3c}
.hero-actions .btn-primary:hover{background:#ffe9cf;color:#1a2b3c}
.hero-actions .btn-ghost{color:#fff;border-color:rgba(255,255,255,.5)}
.hero-actions .btn-ghost:hover{border-color:#fff;color:#fff;background:rgba(255,255,255,.1)}
.hero-stats{display:flex;gap:0;margin-top:40px;padding-top:24px;border-top:1px solid rgba(255,255,255,.28);font-family:var(--mono)}
.stat{flex:1;padding:0 22px;border-right:1px solid rgba(255,255,255,.28)}
.stat:first-child{padding-left:0}
.stat:last-child{border-right:none}
.stat .num{font-size:20px;font-weight:700;color:#fff}
.stat .lab{font-size:12px;color:rgba(255,255,255,.72);margin-top:2px}

/* ===== 区块标题(editorial) ===== */
.section{padding:72px 0}
.section-head{margin-bottom:34px}
.section-head.center{text-align:center}
.eyebrow{display:block;font-family:var(--mono);font-size:13px;letter-spacing:.2em;color:var(--primary);margin-bottom:10px}
.section-head h2{font-family:var(--serif);font-size:34px;font-weight:700;line-height:1.25;margin-bottom:12px}
.section-head p{color:var(--muted);max-width:640px}
.section-head.center p{margin:0 auto}

/* ===== 迁徙航线横卷 ===== */
.route-line{position:relative;padding:10px 0 26px}
.route-line svg{width:100%;height:auto;display:block}
.route-cities{display:flex;justify-content:space-between;font-family:var(--mono);font-size:12.5px;color:var(--muted);margin-top:8px}

/* ===== 编号章节(三段航程) ===== */
.chapters{display:grid;grid-template-columns:repeat(3,1fr);gap:0;border-top:1px solid var(--line)}
.chapter{padding:28px 26px 30px 0;border-right:1px solid var(--line)}
.chapter:last-child{border-right:none}
.chapter:nth-child(2),.chapter:nth-child(3){padding-left:26px}
.chapter-no{display:block;font-family:var(--mono);font-size:34px;font-weight:700;color:var(--line);line-height:1;margin-bottom:14px}
.chapter h3{font-family:var(--serif);font-size:21px;font-weight:700;margin-bottom:8px}
.chapter p{color:var(--muted);font-size:15px}

/* ===== 大图横带 ===== */
.strip{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}
.strip figure{overflow:hidden;border-radius:4px}
.strip img{width:100%;height:100%;object-fit:cover;aspect-ratio:4/3;filter:saturate(.96);transition:.5s}
.strip figure:hover img{transform:scale(1.05)}
.strip figcaption{font-family:var(--mono);font-size:12px;color:var(--muted);margin-top:10px;letter-spacing:.02em}

/* ===== 左右图文 split ===== */
.split{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:center}
.split.rev .split-media{order:-1}
.split h2{font-family:var(--serif);font-size:30px;font-weight:700;line-height:1.3;margin-bottom:14px}
.split p{color:var(--muted);margin-bottom:12px}
.split ul{list-style:none;margin:18px 0 26px}
.split ul li{padding:10px 0 10px 26px;position:relative;color:var(--muted);border-bottom:1px solid var(--line-soft)}
.split ul li::before{content:"";position:absolute;left:4px;top:18px;width:8px;height:8px;border-radius:50%;background:var(--primary)}
.split-media img{width:100%;border-radius:4px;aspect-ratio:16/11;object-fit:cover}

/* ===== 图标列表(能力) ===== */
.icon{display:inline-flex;width:44px;height:44px;align-items:center;justify-content:center;
  color:var(--sky);border:1px solid var(--line);border-radius:8px;background:var(--card)}

/* ===== 场景图注 ===== */
.gallery{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.gallery-item{overflow:hidden;border-radius:4px;background:var(--card);border:1px solid var(--line)}
.gallery-item img{width:100%;height:100%;object-fit:cover;aspect-ratio:4/3;filter:saturate(.96);transition:.4s}
.gallery-item:hover img{transform:scale(1.04)}
.gallery-item .cap{padding:16px 18px 18px}
.gallery-item .cap h3{font-family:var(--serif);font-size:18px;font-weight:700;margin-bottom:5px}
.gallery-item .cap p{color:var(--muted);font-size:13.5px}
.gallery-item.tall img{aspect-ratio:3/4}

/* ===== 通用网格 + 描边卡 ===== */
.grid{display:grid;gap:18px}
.grid-2{grid-template-columns:repeat(2,1fr)}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}
.card{display:block;background:var(--card);border:1px solid var(--line);border-radius:6px;padding:24px;
  color:var(--ink);transition:.2s}
.card:hover{color:var(--ink);border-color:var(--primary);box-shadow:0 8px 24px rgba(26,43,60,.06)}
.card img{width:100%;height:150px;object-fit:cover;border-radius:4px;margin-bottom:16px}
.card h3{font-family:var(--serif);font-size:18px;font-weight:700;margin-bottom:8px}
.card p{color:var(--muted);font-size:14px}

/* ===== 编号步骤 ===== */
.steps{list-style:none;counter-reset:s}
.steps li{position:relative;padding:26px 30px 26px 92px;border-top:1px solid var(--line)}
.steps li:last-child{border-bottom:1px solid var(--line)}
.steps li::before{counter-increment:s;content:counter(s,decimal-leading-zero);position:absolute;left:0;top:24px;
  font-family:var(--mono);font-size:30px;font-weight:700;color:var(--line)}
.steps h3{font-family:var(--serif);font-size:20px;font-weight:700;margin-bottom:6px}
.steps p{color:var(--muted);font-size:15px}

/* ===== FAQ ===== */
.faq-list{max-width:800px;margin:0 auto}
.faq-item{border-top:1px solid var(--line)}
.faq-item:last-child{border-bottom:1px solid var(--line)}
.faq-q{width:100%;display:flex;justify-content:space-between;align-items:center;gap:14px;background:none;border:none;
  padding:20px 4px;font-family:var(--serif);font-size:17px;font-weight:700;color:var(--ink);cursor:pointer;text-align:left}
.faq-q .plus{font-family:var(--mono);font-size:22px;color:var(--primary);transition:.25s;flex:none}
.faq-item.open .plus{transform:rotate(45deg)}
.faq-a{display:none;padding:0 4px 20px;color:var(--muted);font-size:15px}
.faq-item.open .faq-a{display:block}

/* ===== 表格 / 提示 ===== */
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:6px;background:var(--card)}
table{width:100%;border-collapse:collapse;font-size:15px}
th{background:#eef3f8;color:var(--ink);text-align:left;padding:14px 16px;font-weight:700;white-space:nowrap}
td{padding:14px 16px;border-top:1px solid var(--line-soft);color:var(--muted)}
.tip{background:#fdf0e3;border-left:3px solid var(--primary);padding:15px 18px;border-radius:0 6px 6px 0;
  color:var(--ink);margin:18px 0;font-size:15px}
.callout{background:var(--card);border:1px solid var(--line);padding:20px 22px;border-radius:6px;margin:20px 0;color:var(--ink)}

/* ===== 文章双栏 ===== */
.article-layout{display:grid;grid-template-columns:230px 1fr;gap:40px;align-items:start}
.toc{position:sticky;top:90px;padding:22px 0;border-top:2px solid var(--ink)}
.toc h4{font-family:var(--serif);font-size:15px;margin-bottom:12px}
.toc ul{list-style:none}
.toc li{margin-bottom:9px}
.toc a{color:var(--muted);font-size:14px;line-height:1.5}
.toc a:hover{color:var(--primary)}
.article-card{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:48px 54px}
.article-body h1{font-family:var(--serif);font-size:38px;font-weight:700;line-height:1.25;margin-bottom:16px}
.article-body h2{font-family:var(--serif);font-size:25px;font-weight:700;margin:38px 0 14px;padding-top:20px;border-top:1px solid var(--line-soft)}
.article-body h3{font-size:19px;font-weight:700;margin:28px 0 10px}
.article-body p{color:#33465a;margin-bottom:18px;font-size:16px}
.article-body ul,.article-body ol{margin:0 0 18px 24px;color:#33465a}
.article-body li{margin-bottom:8px}
.article-body img{width:100%;border-radius:6px;margin:24px 0}
.article-meta{display:flex;gap:20px;color:var(--muted);font-family:var(--mono);font-size:13px;margin-bottom:20px;flex-wrap:wrap}
.article-meta span{display:inline-flex;align-items:center;gap:6px}
.related{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:40px;padding-top:26px;border-top:1px solid var(--line)}
.related h3{grid-column:1/-1;font-family:var(--serif);font-size:20px}

/* ===== 平台卡 ===== */
.plat-card{position:relative;overflow:hidden;padding:0;display:block}
.plat-card .top{display:block;height:3px;background:var(--primary)}
.plat-card .body{display:block;padding:24px}
.plat-card .body .icon{color:var(--primary);margin-bottom:12px}
.plat-card h3{font-family:var(--serif);font-size:18px;margin-bottom:6px}
.plat-card p{color:var(--muted);font-size:14px}

/* ===== 页脚 ===== */
.footer{background:var(--footer);color:#c7d4e0;margin-top:30px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:30px;padding:44px 0 40px}
.footer-grid .brand{color:#fff}
.footer-grid p{color:#8aa0b4;font-size:14px;margin-top:10px;max-width:320px}
.footer-grid h4{font-family:var(--serif);font-size:15px;margin-bottom:12px;color:#fff}
.footer-grid ul{list-style:none}
.footer-grid li{margin-bottom:8px}
.footer-grid a{color:#8aa0b4;font-size:14px}
.footer-grid a:hover{color:#fff}
.footer-bottom{padding:20px 0;text-align:center;font-size:14px;color:#6d8298;border-top:1px solid rgba(255,255,255,.08)}

/* ===== 工具 ===== */
.center-hero{max-width:720px;margin:0 auto;padding:90px 28px;text-align:center}
.center-hero h1{font-family:var(--serif);font-size:64px;font-weight:700;color:var(--primary)}
.center-hero h2{font-family:var(--serif);font-size:30px;font-weight:700;margin:10px 0}
.center-hero p{color:var(--muted);margin-bottom:24px}
.search-box input{width:100%;max-width:520px;padding:14px 20px;border:1px solid var(--line);border-radius:8px;
  font-size:16px;background:var(--card);color:var(--ink)}
.search-box input::placeholder{color:var(--muted)}
.search-box input:focus{outline:none;border-color:var(--primary)}
.search-results{margin-top:24px;text-align:left;display:grid;gap:12px}
.to-top{position:fixed;right:24px;bottom:28px;width:46px;height:46px;border-radius:8px;background:var(--primary);color:#fff;
  border:none;cursor:pointer;opacity:0;visibility:hidden;transition:.3s;display:flex;align-items:center;justify-content:center}
.to-top.show{opacity:1;visibility:visible}

/* ===== 面包屑 ===== */
.crumbs{display:flex;align-items:center;gap:8px;flex-wrap:wrap;padding:24px 28px 0;font-family:var(--mono);font-size:13px;color:var(--muted)}
.crumbs a{color:var(--muted)}
.crumbs a:hover{color:var(--primary)}
.crumbs .sep{color:var(--line)}

/* ===== 响应式 ===== */
@media(max-width:960px){
  .nav-links{position:absolute;top:64px;left:0;right:0;margin:0;padding:14px 28px;flex-direction:column;gap:0;
    background:var(--paper);border-bottom:1px solid var(--line);display:none}
  .nav-links.open{display:flex}
  .nav-toggle{display:flex}
  .nav-cta{display:none}
  .hero h1{font-size:42px}
  .hero-stats{flex-direction:column;gap:12px}
  .stat{border-right:none;border-bottom:1px solid rgba(255,255,255,.28);padding:0 0 12px}
  .chapters{grid-template-columns:1fr}.chapter{border-right:none;border-bottom:1px solid var(--line);padding-left:0!important}
  .grid-3,.gallery,.related{grid-template-columns:1fr}
  .grid-4,.strip{grid-template-columns:1fr 1fr}
  .split{grid-template-columns:1fr}.split.rev .split-media{order:0}
  .article-layout{grid-template-columns:1fr}.toc{position:static;display:none}
  .footer-grid{grid-template-columns:1fr 1fr}
}
@media(max-width:560px){
  .grid-4,.strip,.grid-2{grid-template-columns:1fr}
  .hero h1{font-size:33px}
  .article-card{padding:28px 22px}
}