*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:"Noto Sans SC",system-ui,sans-serif;background:#fff;color:#1a1a1a;line-height:1.78;font-size:16px}
a{color:#e65100;text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;height:auto;display:block}

.site-header{background:#fff;border-bottom:1px solid #eee;position:sticky;top:0;z-index:300}
.header-inner{max-width:1080px;margin:0 auto;padding:12px 20px;display:flex;align-items:center;justify-content:space-between;gap:16px}
.brand{display:flex;align-items:center;gap:10px;color:#111;font-weight:600;font-size:.95rem}
.brand:hover{text-decoration:none}
.brand img{border-radius:8px}
.brand em{font-style:normal;color:#e65100;font-weight:700}
.site-nav ul{display:flex;flex-wrap:wrap;gap:6px 18px;list-style:none}
.site-nav a{color:#555;font-size:.9rem;padding:4px 0}
.site-nav a.active{color:#e65100;font-weight:600;border-bottom:2px solid #e65100}
.nav-toggle{display:none;background:none;border:none;cursor:pointer;padding:8px;flex-direction:column;gap:5px}
.nav-toggle span{display:block;width:22px;height:2px;background:#333;transition:.2s}
.nav-toggle.is-open span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.nav-toggle.is-open span:nth-child(2){opacity:0}
.nav-toggle.is-open span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

.ads-top-bar{background:#fafafa;border-bottom:1px solid #eee;padding:10px 0}
.applist-title{font-size:.78rem;color:#888;text-align:center;margin-bottom:6px}
#ads{display:flex;justify-content:center;flex-wrap:wrap;gap:12px}
#ads .caption{font-size:.7rem;color:#666;margin-top:4px;text-align:center;max-width:70px;line-height:1.3}

.shell{max-width:1080px;margin:0 auto;padding:28px 20px 52px}

.intro-split{display:grid;grid-template-columns:1.15fr .85fr;gap:28px;align-items:center;margin-bottom:32px;padding:28px 26px;background:linear-gradient(145deg,#fff8f0 0%,#fff 70%);border:1px solid #ffe0b2;border-radius:18px}
.intro-split h1{font-size:1.72rem;line-height:1.35;margin-bottom:14px;color:#111}
.intro-split .lead{color:#444;font-size:1.02rem;margin-bottom:10px}
.intro-split .tag{display:inline-block;background:#e65100;color:#fff;font-size:.78rem;font-weight:600;padding:5px 14px;border-radius:999px;margin-bottom:12px;letter-spacing:.04em}
.intro-visual{border-radius:14px;overflow:hidden;border:1px solid #ffe0b2;box-shadow:0 8px 24px rgba(230,81,0,.1)}
.intro-visual img{width:100%;aspect-ratio:4/3;object-fit:cover}

.step-ribbon{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:36px;padding:14px 16px;background:#fafafa;border:1px solid #eee;border-radius:12px}
.step-ribbon a{display:inline-flex;align-items:center;gap:6px;padding:8px 14px;background:#fff;border:1px solid #e8e8e8;border-radius:999px;font-size:.84rem;color:#555;text-decoration:none;transition:.2s}
.step-ribbon a:hover{border-color:#ffcc80;color:#e65100;background:#fff8f0;text-decoration:none}
.step-ribbon a .dot{display:inline-flex;align-items:center;justify-content:center;width:22px;height:22px;background:#e65100;color:#fff;font-size:.72rem;font-weight:700;border-radius:50%}

.zig-block{position:relative;margin-bottom:42px;padding:26px 28px 28px;background:#fff;border:1px solid #eee;border-radius:16px;box-shadow:0 2px 12px rgba(0,0,0,.04)}
.zig-block:nth-child(odd){margin-left:0;margin-right:48px}
.zig-block:nth-child(even){margin-left:48px;margin-right:0;border-left:4px solid #e65100}
.zig-block h2{font-size:1.2rem;margin-bottom:12px;color:#222;display:flex;align-items:center;gap:10px}
.zig-block h2 .mark{display:inline-flex;align-items:center;justify-content:center;min-width:28px;height:28px;padding:0 8px;background:#fff3e0;color:#e65100;font-size:.78rem;font-weight:700;border-radius:6px}
.zig-block p{margin-bottom:11px;color:#333}
.zig-block figure{margin:18px 0;border-radius:12px;overflow:hidden;border:1px solid #eee}
.zig-block figcaption{font-size:.84rem;color:#777;padding:8px 12px;background:#fafafa}
.callout{background:#fff8e1;border-left:4px solid #ffb300;padding:14px 18px;margin:16px 0;border-radius:0 8px 8px 0;font-size:.94rem;color:#444}

.mosaic{margin:36px 0 40px}
.mosaic h2{font-size:1.15rem;margin-bottom:6px;color:#222}
.mosaic-sub{font-size:.88rem;color:#777;margin-bottom:16px}
.mosaic-grid{display:grid;grid-template-columns:1.2fr .8fr;grid-template-rows:auto auto;gap:14px}
.mosaic-grid .tile{border-radius:12px;overflow:hidden;border:1px solid #eee;background:#fff}
.mosaic-grid .tile img{width:100%;height:100%;object-fit:cover;min-height:140px}
.mosaic-grid .tile.tall{grid-row:span 2}
.mosaic-grid .tile .lbl{padding:10px 12px;font-size:.82rem;color:#555;background:#fafafa}

.triptych{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:36px 0 32px}
.tri-card{background:#fafafa;border:1px solid #ececec;border-radius:12px;padding:20px 18px;text-align:center}
.tri-card .icon{font-size:1.4rem;margin-bottom:8px}
.tri-card h3{font-size:.95rem;color:#222;margin-bottom:8px}
.tri-card p{font-size:.86rem;color:#555;line-height:1.55}

.closing-panel{background:linear-gradient(135deg,#fff8f0,#fff);border:1px solid #ffe0b2;border-radius:16px;padding:28px 26px;margin-bottom:24px}
.closing-panel h2{font-size:1.12rem;margin-bottom:12px;color:#222}
.closing-panel p{margin-bottom:10px;color:#333}
.internal-links{display:flex;flex-wrap:wrap;gap:10px;margin-top:18px}
.internal-links a{display:inline-block;padding:8px 14px;background:#fff;border:1px solid #e0e0e0;border-radius:999px;font-size:.88rem;color:#555}
.internal-links a:hover{background:#fff3e0;border-color:#ffcc80;color:#e65100;text-decoration:none}

.site-footer{background:#fafafa;border-top:1px solid #eee;padding:28px 20px;text-align:center;font-size:.88rem;color:#666}
.footer-links{display:flex;flex-wrap:wrap;justify-content:center;gap:8px 16px;margin-bottom:10px}
.footer-links a{color:#555}

.prose-page{max-width:780px;margin:0 auto;padding:32px 20px 48px}
.prose-page h1{font-size:1.5rem;margin-bottom:16px}
.prose-page h2{font-size:1.12rem;margin:22px 0 10px}
.prose-page p{margin-bottom:12px;color:#333}
.error-page{max-width:520px;margin:80px auto;padding:0 20px;text-align:center}
.error-page h1{font-size:1.4rem;margin-bottom:12px}
.error-page p{color:#666;margin-bottom:20px}

@media(max-width:900px){
  .intro-split{grid-template-columns:1fr}
  .intro-visual{max-width:420px;margin:0 auto}
  .zig-block:nth-child(odd),.zig-block:nth-child(even){margin-left:0;margin-right:0}
  .mosaic-grid{grid-template-columns:1fr}
  .mosaic-grid .tile.tall{grid-row:span 1}
  .triptych{grid-template-columns:1fr}
}
@media(max-width:768px){
  .nav-toggle{display:flex}
  .site-nav{position:absolute;top:100%;left:0;right:0;background:#fff;border-bottom:1px solid #eee;padding:12px 20px;display:none;box-shadow:0 4px 12px rgba(0,0,0,.08)}
  .site-nav.is-open{display:block}
  .site-nav ul{flex-direction:column;gap:10px}
  .site-header{position:relative}
}