*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --ink:#14213d;--muted:#4a5568;--line:#dce4ec;
  --teal:#0d9488;--teal-soft:#ecfdf5;--coral:#ea580c;--coral-soft:#fff7ed;
  --header-h:56px;--content:840px;--card-radius:12px;
}
html{scroll-behavior:smooth}
body{font-family:"Noto Sans SC",system-ui,sans-serif;color:var(--ink);background:#fff;line-height:1.78;font-size:16px}
img{max-width:100%;height:auto;display:block}
a{color:var(--teal);text-decoration:none}
a:hover{text-decoration:underline}

.site-header{position:sticky;top:0;z-index:300;background:#fff;border-bottom:3px solid var(--teal)}
.header-inner{max-width:980px;margin:0 auto;padding:0 1rem;display:flex;align-items:center;justify-content:space-between;min-height:var(--header-h)}
.brand{display:flex;align-items:center;gap:.65rem;color:var(--ink);font-size:.9rem;text-decoration:none}
.brand:hover{text-decoration:none}
.brand em{font-style:normal;font-weight:700;color:var(--teal)}
.brand span{line-height:1.3;max-width:340px}

.nav-toggle{display:none;background:none;border:none;cursor:pointer;padding:.5rem;flex-direction:column;gap:5px}
.nav-toggle span{display:block;width:22px;height:2px;background:var(--ink);transition:transform .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)}

.site-nav ul{display:flex;gap:1rem;list-style:none}
.site-nav a{color:var(--muted);font-size:.88rem;text-decoration:none}
.site-nav a:hover,.site-nav a.active{color:var(--teal);font-weight:600}

.ads-top-bar{background:var(--teal-soft);border-bottom:1px solid var(--line);padding:.5rem 0}
#applist{display:flex;align-items:center;gap:1rem;flex-wrap:wrap}
.applist-title{font-size:.78rem;color:var(--muted);white-space:nowrap}
#ads{display:flex;gap:.75rem;flex-wrap:wrap}
.ads-item figure{margin:0;text-align:center}
.ads-item img{border-radius:8px}
.ads-item .caption{font-size:.68rem;color:var(--muted);margin-top:.2rem;max-width:65px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

.page-wrap{max-width:var(--content);margin:0 auto;padding:2rem 1.25rem 4rem}

.hero-band{
  background:repeating-linear-gradient(-55deg,var(--teal-soft),var(--teal-soft) 12px,#fff 12px,#fff 24px);
  border:1px solid var(--line);border-left:5px solid var(--coral);border-radius:0 16px 16px 0;
  padding:2rem 1.85rem 1.75rem;margin-bottom:2.25rem;
}
.hero-tag{display:inline-block;font-size:.76rem;font-weight:600;color:var(--coral);background:#fff;border:1px solid var(--coral);padding:.22rem .75rem;border-radius:4px;margin-bottom:.85rem}
.hero-band h1{font-size:1.58rem;line-height:1.38;font-weight:700;margin-bottom:.85rem;color:var(--ink);max-width:660px}
.hero-lead{font-size:1rem;color:var(--muted);margin-bottom:.65rem;text-align:justify;max-width:700px}
.hero-chips{display:flex;flex-wrap:wrap;gap:.45rem;margin-top:1.1rem}
.hero-chips span{font-size:.76rem;background:#fff;border:1px solid var(--line);color:var(--muted);padding:.22rem .65rem;border-radius:4px}

.section-jump{display:flex;flex-wrap:wrap;gap:.55rem;margin-bottom:1.5rem;padding-bottom:1.15rem;border-bottom:2px dotted var(--line)}
.section-jump a{font-size:.82rem;color:var(--muted);background:var(--coral-soft);padding:.32rem .75rem;border-radius:4px;border:1px solid var(--line)}
.section-jump a:hover{color:var(--coral);text-decoration:none;border-color:var(--coral)}

.stack-zone{position:relative;padding:1.5rem 0 3.5rem;perspective:1200px}
.stack-card{
  position:relative;background:#fff;border:1px solid var(--line);border-left:4px solid var(--teal);
  border-radius:var(--card-radius);padding:1.55rem 1.65rem 1.45rem;
  margin-bottom:-2.1rem;
  box-shadow:var(--shadow,0 4px 18px rgba(20,33,61,.06));
  transform:translateX(var(--shift,0)) scale(var(--scale,1)) translateY(var(--lift,0));
  transform-origin:center top;transition:transform .32s ease,box-shadow .32s ease,border-color .32s;
  z-index:var(--z,1);cursor:pointer;
}
.stack-card:last-child{margin-bottom:0}
.stack-card:nth-child(1){--shift:-4px;--scale:.992}
.stack-card:nth-child(2){--shift:8px;--scale:.985}
.stack-card:nth-child(3){--shift:-10px;--scale:.978}
.stack-card:nth-child(4){--shift:12px;--scale:.971}
.stack-card:nth-child(5){--shift:-6px;--scale:.964}
.stack-card:nth-child(6){--shift:14px;--scale:.957}
.stack-card:nth-child(7){--shift:-8px;--scale:.95}
.stack-card:nth-child(8){--shift:6px;--scale:.943}
.stack-card:nth-child(9){--shift:-2px;--scale:.936}
.stack-card.is-front{
  --shift:0;--scale:1;--lift:-8px;
  z-index:90!important;
  --shadow:0 20px 48px rgba(13,148,136,.16);
  border-left-color:var(--coral);border-color:#99f6e4;
}
.stack-card:focus{outline:2px solid var(--teal);outline-offset:3px}
.stack-card:focus:not(:focus-visible){outline:none}

.card-meta{display:flex;align-items:center;gap:.65rem;margin-bottom:.7rem}
.card-step{
  flex-shrink:0;width:30px;height:30px;border-radius:50%;background:var(--coral);color:#fff;
  display:flex;align-items:center;justify-content:center;font-size:.74rem;font-weight:700;
}
.card-tag{font-size:.72rem;font-weight:600;color:var(--teal);letter-spacing:.05em;text-transform:uppercase}
.stack-card h2{font-size:1.06rem;color:var(--ink);margin-bottom:.72rem;font-weight:600;line-height:1.44;border-bottom:1px dashed var(--line);padding-bottom:.45rem}
.stack-card p{margin-bottom:.9rem;text-align:justify;color:#243047}
.stack-card ul{margin:.6rem 0 1rem 1.15rem;color:#243047}
.stack-card li{margin-bottom:.38rem}
.stack-card figure{margin:1.1rem 0;border-radius:8px;overflow:hidden;border:1px solid var(--line)}
.stack-card figcaption{font-size:.82rem;color:var(--muted);padding:.5rem .75rem;background:var(--teal-soft);text-align:center}

.tip-strip{
  background:var(--coral-soft);border-left:4px solid var(--coral);
  padding:.82rem 1rem;border-radius:0 6px 6px 0;font-size:.91rem;margin:1rem 0;color:#9a3412;
}

.bottom-links{display:flex;flex-wrap:wrap;gap:.65rem;margin-top:2.25rem;padding-top:1.5rem;border-top:1px solid var(--line)}
.bottom-links a{font-size:.86rem;color:var(--muted);background:var(--teal-soft);padding:.35rem .85rem;border-radius:4px;border:1px solid var(--line)}
.bottom-links a:hover{color:var(--teal);text-decoration:none;border-color:var(--teal)}

.prose-page{max-width:var(--content);margin:0 auto;padding:2rem 1.25rem 3rem}
.prose-page h1{font-size:1.48rem;margin-bottom:1rem;color:var(--teal)}
.prose-page p{margin-bottom:.95rem}

.error-page{max-width:var(--content);margin:4rem auto;padding:2rem 1.25rem;text-align:center}
.error-page h1{font-size:3rem;color:var(--teal);margin-bottom:.5rem}

.site-footer{background:var(--teal-soft);border-top:3px solid var(--teal);padding:1.5rem 1rem;text-align:center;font-size:.82rem;color:var(--muted)}
.footer-links{display:flex;flex-wrap:wrap;justify-content:center;gap:.5rem 1rem;margin-bottom:.65rem}
.footer-links a{color:var(--muted)}
.footer-sub{font-size:.76rem;margin-top:.35rem;color:#888}

@media(max-width:640px){
  .nav-toggle{display:flex}
  .site-nav{position:absolute;top:100%;left:0;right:0;background:#fff;border-bottom:1px solid var(--line);padding:.75rem 1rem;display:none;box-shadow:0 4px 14px rgba(0,0,0,.06)}
  .site-nav.is-open{display:block}
  .site-nav ul{flex-direction:column;gap:.5rem}
  .stack-card{margin-bottom:-1.35rem;padding:1.3rem 1.15rem;--shift:0!important;--scale:1!important}
  .hero-band h1{font-size:1.32rem}
  .section-jump{display:none}
}