:root{
  --ink:#1f2a24; --muted:#56655c; --line:#dfe3dc; --paper:#f5f3ed; --card:#fff;
  --green:#24503b; --green-2:#2f6a4e; --deep:#183a29; --leaf:#e4ece3; --amber:#9a6224;
  --serif:"Noto Serif SC","Source Han Serif SC","Songti SC","STSong","SimSun",serif;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.85 -apple-system,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif}
img{max-width:100%;display:block}
a{color:inherit}
.wrap{max-width:1120px;margin:0 auto;padding:0 28px}
.preview-bar{background:#33302a;color:#f4efe4;text-align:center;font-size:13px;line-height:1.5;padding:7px 16px}

/* 导航 */
.nav{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:5}
.nav .wrap{display:flex;align-items:center;justify-content:space-between;gap:20px;min-height:64px}
.logo{font-family:var(--serif);font-weight:900;font-size:21px;color:var(--green);text-decoration:none;white-space:nowrap}
.nav ul{display:flex;gap:4px;list-style:none;margin:0;padding:0}
.nav a.item{display:block;padding:8px 12px;font-size:15px;text-decoration:none;color:#3a4a40;border-radius:8px;transition:background .2s,color .2s}
.nav a.item:hover{background:var(--leaf);color:var(--green)}
.nav a.item.on{color:var(--green);font-weight:600;box-shadow:inset 0 -2px 0 var(--green);border-radius:0}

/* 首页大图 */
.hero{position:relative;min-height:440px;display:flex;align-items:flex-end;color:#fff;background:#1d3d2b center/cover no-repeat}
.hero::before{content:"";position:absolute;inset:0;background:linear-gradient(180deg,rgba(15,35,24,.15) 0%,rgba(15,35,24,.55) 55%,rgba(15,35,24,.88) 100%)}
.hero .wrap{position:relative;width:100%;padding-bottom:44px}
.hero h1{margin:0;font-family:var(--serif);font-weight:900;font-size:52px;line-height:1.2;letter-spacing:.02em;text-wrap:balance}
.hero p{margin:10px 0 0;font-family:var(--serif);font-size:21px;opacity:.92}
.hero.small{min-height:260px}
.hero.small h1{font-size:40px}

.info{background:var(--green);color:#eef3ec}
.info .wrap{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.2fr);gap:28px;padding-top:30px;padding-bottom:30px}
.info dl{margin:0;display:grid;grid-template-columns:auto 1fr;gap:4px 16px;font-size:16px}
.info dt{color:#b7cbbb}
.info dd{margin:0}
.info .yuan{background:rgba(255,255,255,.08);border-radius:12px;padding:16px 20px;font-size:15px;line-height:1.8}
.info .yuan b{display:block;font-family:var(--serif);font-size:17px;margin-bottom:4px;color:#fff}

/* 通用区块 */
.block{padding:64px 0}
.block + .block{padding-top:0}
.h2{font-family:var(--serif);font-weight:900;font-size:30px;color:var(--green);margin:0 0 22px;line-height:1.35}
.h3{font-family:var(--serif);font-weight:700;font-size:21px;color:var(--deep);margin:0 0 10px;line-height:1.45}
.lead{font-size:17px;color:#33433a}
.prose p{margin:0 0 1em;max-width:42em}
.two{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(0,1fr);gap:44px;align-items:start}
.photo{border-radius:14px;overflow:hidden;box-shadow:0 10px 30px rgba(20,40,28,.14)}
.photo img{width:100%;height:100%;object-fit:cover}
.cap{font-size:12px;color:var(--muted);margin-top:8px}

/* 首页导览 */
.guide{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:0;border-top:1px solid var(--line)}
.guide a{display:block;padding:22px 20px 24px 0;text-decoration:none;border-bottom:1px solid var(--line)}
.guide a + a{padding-left:20px;border-left:1px solid var(--line)}
.guide b{display:block;font-family:var(--serif);font-size:19px;color:var(--green);margin-bottom:4px}
.guide span{font-size:14px;color:var(--muted)}
.guide a:hover b{text-decoration:underline;text-underline-offset:4px}

/* 主题简介 */
.facts{margin:0}
.facts div{display:grid;grid-template-columns:7em 1fr;gap:16px;padding:16px 0;border-top:1px solid var(--line)}
.facts div:first-child{border-top:0;padding-top:0}
.facts dt{font-family:var(--serif);font-weight:700;color:var(--green)}
.facts dd{margin:0}

/* 理论 */
.tiles{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;margin-bottom:56px}
.tile{display:block;background:var(--card);border-radius:14px;padding:20px 20px 18px;text-decoration:none;box-shadow:0 2px 12px rgba(20,40,28,.06);transition:transform .25s cubic-bezier(.16,1,.3,1),box-shadow .25s}
.tile:hover{transform:translateY(-3px);box-shadow:0 10px 24px rgba(20,40,28,.12)}
.tile b{display:block;font-family:var(--serif);font-size:18px;color:var(--deep);margin-bottom:6px;line-height:1.45}
.tile span{font-size:14px;color:var(--muted);line-height:1.7}
.tile i{display:block;font-style:normal;font-size:13px;color:var(--green-2);margin-top:10px}
.art{background:var(--card);border-radius:14px;padding:30px 34px;margin-bottom:20px;scroll-margin-top:84px}
.art .sub{color:var(--green-2);font-size:15px;margin:-4px 0 14px}

/* 案例 */
.case{display:grid;grid-template-columns:300px minmax(0,1fr);gap:36px;padding:40px 0;border-top:1px solid var(--line)}
.case:first-of-type{border-top:0;padding-top:0}
.case .photo{aspect-ratio:4/3}
.tag{display:inline-block;font-size:13px;background:var(--leaf);color:var(--green);border-radius:999px;padding:1px 12px;margin-bottom:8px}
.yl{margin-top:6px;background:var(--leaf);border-radius:12px;padding:14px 18px;font-size:15px;color:#24473a;max-width:42em}
.yl b{color:var(--green)}
.paper{aspect-ratio:4/3;border-radius:14px;background:#efe9da;color:#2b2a26;padding:22px 22px 18px;display:flex;flex-direction:column;box-shadow:0 10px 30px rgba(20,40,28,.14);font-family:var(--serif)}
.paper .mast{font-size:30px;font-weight:900;letter-spacing:.2em;border-bottom:3px double #2b2a26;padding-bottom:6px;text-align:center}
.paper .date{font-size:12px;text-align:center;margin:6px 0 14px;letter-spacing:.08em}
.paper .head{font-size:22px;font-weight:900;line-height:1.35;text-align:center;margin:auto 0}
.paper .by{font-size:12px;text-align:center;margin-top:12px}

/* 互动 */
.feel h3{font-family:var(--serif);font-size:19px;color:var(--deep);margin:28px 0 8px}
.q{background:var(--card);border-radius:14px;padding:20px 22px;margin-bottom:14px}
.q .n{font-family:var(--serif);font-weight:700;color:var(--amber);font-size:15px}
.q p{margin:4px 0 8px;font-size:17px}
.q details summary{cursor:pointer;color:var(--green-2);font-size:14px;list-style:none}
.q details summary::-webkit-details-marker{display:none}
.q details summary::before{content:"＋ ";}
.q details[open] summary::before{content:"－ ";}
.q details div{font-size:15px;color:var(--muted);margin-top:6px}
.note-box{background:var(--leaf);border-radius:14px;padding:24px 26px}

.foot{background:var(--deep);color:#b7cbbb;font-size:13px;line-height:1.8}
.foot .wrap{padding-top:28px;padding-bottom:32px}
.foot b{color:#e6efe7;font-family:var(--serif);font-size:16px}
.foot small{display:block;margin-top:10px;opacity:.8}

@media (max-width:860px){
  .wrap{padding:0 16px}
  .nav .wrap{flex-direction:column;align-items:flex-start;gap:0;padding-top:10px}
  .nav nav{width:100%;overflow-x:auto;scrollbar-width:none}
  .nav nav::-webkit-scrollbar{display:none}
  .nav ul{padding-bottom:2px}
  .nav ul::-webkit-scrollbar{display:none}
  .nav a.item{padding:8px 7px;font-size:14px;white-space:nowrap}
  .logo{font-size:19px}
  .hero{min-height:330px}.hero h1{font-size:34px}.hero p{font-size:17px}
  .hero.small{min-height:200px}.hero.small h1{font-size:30px}
  .info .wrap,.two,.case{grid-template-columns:1fr;gap:22px}
  .tiles{grid-template-columns:1fr 1fr;gap:12px}
  .guide{grid-template-columns:1fr 1fr}
  .guide a,.guide a + a{padding:18px 14px 18px 0;border-left:0}
  .guide a:nth-child(2n){padding-left:14px;border-left:1px solid var(--line)}
  .block{padding:44px 0}
  .h2{font-size:25px}
  .art{padding:22px 18px}
  .facts div{grid-template-columns:1fr;gap:2px}
  .case{padding:30px 0}
}
@media (max-width:420px){
  .tiles{grid-template-columns:1fr}
  .tile i{display:none}
}

/* 可访问性 */
a,summary{-webkit-tap-highlight-color:rgba(36,80,59,.15);touch-action:manipulation}
a:focus-visible,summary:focus-visible{outline:2px solid var(--green);outline-offset:3px;border-radius:6px}
.skip{position:absolute;left:12px;top:-60px;background:var(--green);color:#fff;padding:8px 14px;border-radius:8px;z-index:20;text-decoration:none}
.skip:focus{top:12px}
@media (prefers-reduced-motion:reduce){.tile,.nav a.item{transition:none}.tile:hover{transform:none}}