/* =========================================================================
   THE COLD CITY — Yung-Lung Chen
   A private literary archive beneath New York.
   Design language: Archive White ground · one impossible green line ·
   high-contrast Didone headlines · quiet bronze labels · archive-file frames.
   ========================================================================= */

/* ----------------------------------------------------------------- Tokens */
:root{
  /* Palette */
  --archive-white:#F7F4EE;
  --ink-black:#111111;
  --institution-gray:#4A4D50;
  --soft-paper:#DAD7CF;
  --bronze:#8F7850;
  --green:#137A52;
  --green-deep:#0E5C3E;
  --night-ink:#101820;

  /* Derived */
  --paper:#FBFAF6;          /* slightly lighter card fill */
  --line:#DAD7CF;
  --line-soft:rgba(17,17,17,.10);
  --ink-soft:rgba(17,17,17,.64);
  --on-dark:#EDEAE2;
  --on-dark-soft:rgba(237,234,226,.66);
  --on-dark-line:rgba(237,234,226,.16);

  /* Type */
  --serif:'Playfair Display', Georgia, 'Times New Roman', serif;
  --sans:'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;

  /* Rhythm */
  --container:1140px;
  --container-wide:1280px;
  --container-narrow:760px;
  --gutter:clamp(20px, 5vw, 48px);
  --section-y:clamp(64px, 9vw, 132px);
  --radius:3px;

  --shadow-card:0 18px 50px -28px rgba(16,24,32,.42);
  --shadow-soft:0 2px 14px -6px rgba(16,24,32,.18);
}

/* ----------------------------------------------------------------- Reset */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{
  margin:0;
  background:var(--archive-white);
  color:var(--ink-black);
  font-family:var(--sans);
  font-size:17px;
  line-height:1.65;
  font-weight:400;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
img{max-width:100%;height:auto;display:block}
a{color:inherit}
h1,h2,h3,h4{margin:0;font-family:var(--serif);font-weight:700;line-height:1.08;letter-spacing:-.01em}
p{margin:0}
ul{margin:0;padding:0;list-style:none}
button{font-family:inherit}

/* Accessible focus */
a:focus-visible,button:focus-visible,input:focus-visible{
  outline:2px solid var(--green);
  outline-offset:3px;
  border-radius:2px;
}

.skip-link{
  position:absolute;left:-9999px;top:0;z-index:200;
  background:var(--night-ink);color:#fff;padding:12px 18px;
  font-family:var(--sans);font-size:14px;font-weight:600;border-radius:0 0 3px 0;
}
.skip-link:focus{left:0}

.visually-hidden{
  position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0;
}

/* --------------------------------------------------------------- Layout */
.container{width:100%;max-width:var(--container);margin:0 auto;padding-inline:var(--gutter)}
.container--wide{max-width:var(--container-wide)}
.container--narrow{max-width:var(--container-narrow)}

.section{padding-block:var(--section-y)}
.section--tight{padding-block:clamp(48px,6vw,80px)}
.section--paper{background:var(--soft-paper)}
.section--paper-soft{background:linear-gradient(180deg,#F2EEE5,#F7F4EE)}
.section--dark{background:var(--night-ink);color:var(--on-dark)}
.section--dark h1,.section--dark h2,.section--dark h3{color:#fff}
.section--dark .lede,.section--dark p{color:var(--on-dark-soft)}
.section--dark .kicker{color:var(--bronze)}
.section + .section--dark, .section--dark + .section{border:0}

.divider{border:0;height:1px;background:var(--line);margin:0}

/* ------------------------------------------------------- Green line motif */
/* The one impossible green line — a subway line ending in a bronze token. */
.greenline{
  position:relative;display:block;height:2px;width:clamp(96px,18vw,200px);
  background:var(--green);margin:0;border:0;
}
.greenline::after{
  content:"";position:absolute;right:-5px;top:50%;width:9px;height:9px;
  transform:translateY(-50%);border-radius:50%;background:var(--bronze);
}
.greenline--full{width:100%}
.greenline--center{margin-inline:auto}
.section--dark .greenline{background:#1B9669}

/* small bronze tick used above kickers occasionally */
.kicker{
  display:inline-block;font-family:var(--sans);font-weight:600;
  font-size:12.5px;letter-spacing:.22em;text-transform:uppercase;
  color:var(--bronze);margin:0 0 18px;
}
.eyebrow{
  font-family:var(--sans);font-weight:600;font-size:13px;letter-spacing:.14em;
  text-transform:uppercase;color:var(--institution-gray);
}

/* --------------------------------------------------------------- Type scale */
.display{font-size:clamp(2.4rem,6.4vw,4.6rem);line-height:1.02;letter-spacing:-.02em}
.h-xl{font-size:clamp(2rem,4.8vw,3.3rem)}
.h-lg{font-size:clamp(1.7rem,3.6vw,2.5rem)}
.h-md{font-size:clamp(1.35rem,2.6vw,1.85rem)}
.h-sm{font-size:clamp(1.15rem,2vw,1.4rem)}

.lede{
  font-size:clamp(1.06rem,1.7vw,1.28rem);line-height:1.6;
  color:var(--institution-gray);font-weight:400;max-width:60ch;
}
.prose-serif{font-family:var(--serif);font-weight:400}
.core-lines{
  font-family:var(--serif);font-style:italic;font-weight:600;
  font-size:clamp(1.3rem,2.6vw,1.9rem);line-height:1.28;color:var(--ink-black);
  letter-spacing:-.01em;
}
.section--dark .core-lines{color:#fff}
.muted{color:var(--institution-gray)}
.text-green{color:var(--green-deep)}

/* --------------------------------------------------------------- Header */
.site-header{
  position:sticky;top:0;z-index:100;background:rgba(247,244,238,.92);
  backdrop-filter:saturate(120%) blur(8px);
  border-bottom:1px solid var(--line);
}
.site-header.is-scrolled{box-shadow:0 1px 0 rgba(17,17,17,.04),0 10px 30px -24px rgba(16,24,32,.5)}
.header-inner{
  display:flex;align-items:center;justify-content:space-between;gap:24px;
  min-height:74px;padding-block:12px;
}
.brand{display:inline-flex;align-items:center;flex-shrink:0;text-decoration:none}
.brand img{height:30px;width:auto}
.primary-nav{display:flex;align-items:center;gap:30px}
.primary-nav a{
  font-family:var(--sans);font-weight:500;font-size:15px;text-decoration:none;
  color:var(--institution-gray);position:relative;padding-block:6px;
  transition:color .18s ease;letter-spacing:.005em;
}
.primary-nav a::after{
  content:"";position:absolute;left:0;right:100%;bottom:0;height:1.5px;
  background:var(--green);transition:right .22s ease;
}
.primary-nav a:hover{color:var(--ink-black)}
.primary-nav a:hover::after,.primary-nav a[aria-current="page"]::after{right:0}
.primary-nav a[aria-current="page"]{color:var(--ink-black)}
.header-actions{display:flex;align-items:center;gap:14px}

.nav-toggle{
  display:none;align-items:center;justify-content:center;
  width:46px;height:46px;background:transparent;border:1px solid var(--line);
  border-radius:3px;cursor:pointer;color:var(--ink-black);
}
.nav-toggle svg{width:22px;height:22px}
.nav-toggle .icon-close{display:none}
.nav-toggle[aria-expanded="true"] .icon-open{display:none}
.nav-toggle[aria-expanded="true"] .icon-close{display:block}

@media (max-width:960px){
  .primary-nav,.header-actions .btn{display:none}
  .nav-toggle{display:inline-flex}
  .mobile-nav{display:block}
}

/* Mobile slide-down panel */
.mobile-nav{
  display:none;border-bottom:1px solid var(--line);background:var(--archive-white);
  overflow:hidden;max-height:0;transition:max-height .32s ease;
}
.mobile-nav.is-open{max-height:560px}
.mobile-nav-inner{padding:14px var(--gutter) 30px;display:flex;flex-direction:column;gap:4px}
.mobile-nav a{
  font-family:var(--sans);font-weight:500;font-size:18px;text-decoration:none;
  color:var(--ink-black);padding:14px 4px;border-bottom:1px solid var(--line-soft);
}
.mobile-nav a:last-of-type{border-bottom:0}
.mobile-nav .btn{margin-top:18px}

/* --------------------------------------------------------------- Buttons */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:10px;
  font-family:var(--sans);font-weight:600;font-size:15.5px;letter-spacing:.01em;
  line-height:1;text-decoration:none;cursor:pointer;
  padding:16px 26px;min-height:54px;border:1.5px solid transparent;
  border-radius:var(--radius);transition:background .18s ease,color .18s ease,border-color .18s ease,transform .12s ease;
  text-align:center;
}
.btn:active{transform:translateY(1px)}
.btn--primary{background:var(--ink-black);color:#fff;border-color:var(--ink-black)}
.btn--primary:hover{background:var(--night-ink);border-color:var(--night-ink)}
.btn--green{background:var(--green);color:#fff;border-color:var(--green)}
.btn--green:hover{background:var(--green-deep);border-color:var(--green-deep)}
.btn--ghost{background:transparent;color:var(--ink-black);border-color:rgba(17,17,17,.24)}
.btn--ghost:hover{background:var(--ink-black);color:#fff;border-color:var(--ink-black)}
.btn--bronze{background:transparent;color:var(--bronze);border-color:rgba(143,120,80,.5)}
.btn--bronze:hover{background:var(--bronze);color:#fff;border-color:var(--bronze)}
.btn--block{width:100%}
.btn .arrow{font-size:1.05em;line-height:0;transform:translateY(.5px)}

/* On dark sections */
.section--dark .btn--ghost,.footer .btn--ghost{color:#fff;border-color:rgba(237,234,226,.4)}
.section--dark .btn--ghost:hover,.footer .btn--ghost:hover{background:#fff;color:var(--night-ink)}
.section--dark .btn--primary{background:var(--archive-white);color:var(--night-ink);border-color:var(--archive-white)}
.section--dark .btn--primary:hover{background:#fff}

.btn-row{display:flex;flex-wrap:wrap;gap:14px}
.btn-row--center{justify-content:center}
@media (max-width:520px){
  .btn-row .btn{width:100%}
}

/* --------------------------------------------------------------- Archive card / frame */
.archive-frame{
  border:1px solid var(--line);background:var(--paper);
  padding:clamp(26px,4vw,52px);position:relative;border-radius:var(--radius);
}
.archive-frame--double{
  border-color:var(--line);background:transparent;
  padding:clamp(16px,2.6vw,30px);
}
.archive-card{
  background:var(--archive-white);border:1px solid var(--line);
  padding:clamp(26px,4vw,46px);box-shadow:var(--shadow-card);border-radius:var(--radius);
}
.file-tab{
  display:inline-flex;align-items:center;gap:10px;font-family:var(--sans);
  font-size:11.5px;font-weight:600;letter-spacing:.2em;text-transform:uppercase;
  color:var(--institution-gray);
}
.file-tab .dot{width:6px;height:6px;border-radius:50%;background:var(--green)}

/* --------------------------------------------------------------- Hero (split) */
.hero{padding-block:clamp(56px,8vw,110px)}
.hero-grid{
  display:grid;grid-template-columns:1.05fr .95fr;gap:clamp(36px,6vw,80px);
  align-items:center;
}
.hero-copy{max-width:38rem}
.hero-copy .display{margin:0 0 22px}
.hero-copy .lede{margin:0 0 30px}
.hero-copy .greenline{margin:0 0 28px}
.hero-visual{position:relative}
@media (max-width:880px){
  .hero-grid{grid-template-columns:1fr;gap:clamp(34px,7vw,52px)}
  .hero-visual{order:2;max-width:520px;margin-inline:auto;width:100%}
  .hero-copy{order:1;max-width:none}
}

/* --------------------------------------------------------------- Book covers */
.covers-duo{
  display:flex;gap:clamp(16px,3vw,30px);align-items:flex-end;justify-content:center;
}
.cover-frame{position:relative;flex:1 1 0;max-width:230px}
.cover-frame--lead{margin-bottom:18px}
.cover{
  width:100%;aspect-ratio:1600/2560;object-fit:cover;background:var(--soft-paper);
  border:1px solid rgba(17,17,17,.12);border-radius:2px;
  box-shadow:var(--shadow-card);
}
.cover--single{max-width:330px;width:100%}
/* graceful placeholder if a remote cover fails to load */
.cover-fallback{
  width:100%;aspect-ratio:1600/2560;border:1px solid var(--line);border-radius:2px;
  background:var(--paper);box-shadow:var(--shadow-card);
  display:none;flex-direction:column;justify-content:space-between;
  padding:22px;text-align:left;
}
.cover-fallback .ttl{font-family:var(--serif);font-weight:800;font-size:1.25rem;line-height:1.1}
.cover-fallback .lbl{font-family:var(--sans);font-size:11px;letter-spacing:.18em;text-transform:uppercase;color:var(--bronze)}
.cover-fallback .gl{height:2px;width:70%;background:var(--green);position:relative}
.cover-fallback .gl::after{content:"";position:absolute;right:-4px;top:-3px;width:8px;height:8px;border-radius:50%;background:var(--bronze)}
.is-broken .cover{display:none}
.is-broken .cover-fallback{display:flex}

.cover-caption{
  margin-top:14px;font-family:var(--sans);font-size:12.5px;letter-spacing:.04em;
  color:var(--institution-gray);text-align:center;
}

/* --------------------------------------------------------------- Numbered spec list */
.spec-list{display:flex;flex-direction:column;gap:14px;margin:0}
.spec-list li{display:flex;gap:16px;align-items:baseline}
.spec-list .num{
  font-family:var(--sans);font-size:12px;font-weight:600;letter-spacing:.08em;
  color:var(--bronze);min-width:22px;padding-top:2px;
}
.spec-list .txt{font-family:var(--sans);font-size:1.02rem;color:var(--ink-black)}
.section--dark .spec-list .txt{color:var(--on-dark)}

/* --------------------------------------------------------------- Feature bullets */
.feature-list{
  display:grid;grid-template-columns:repeat(2,minmax(0,1fr));
  gap:14px 34px;margin:0;
}
.feature-list--single{grid-template-columns:1fr}
.feature-list li{
  position:relative;padding-left:26px;font-family:var(--sans);font-size:1rem;
  color:var(--ink-black);line-height:1.5;
}
.feature-list li::before{
  content:"";position:absolute;left:0;top:.62em;width:12px;height:2px;background:var(--green);
}
.section--dark .feature-list li{color:var(--on-dark)}
@media (max-width:620px){.feature-list{grid-template-columns:1fr}}

/* --------------------------------------------------------------- Generic two-col media row */
.media-row{
  display:grid;grid-template-columns:0.85fr 1.15fr;gap:clamp(32px,6vw,72px);
  align-items:center;
}
.media-row--reverse .media-visual{order:2}
.media-row--reverse .media-copy{order:1}
.media-copy{max-width:40rem}
.media-copy .kicker{margin-bottom:14px}
.media-copy h2{margin-bottom:20px}
.media-copy .greenline{margin:24px 0}
.media-visual img{border-radius:3px}
@media (max-width:860px){
  .media-row,.media-row--reverse{grid-template-columns:1fr;gap:clamp(28px,6vw,44px)}
  .media-row--reverse .media-visual,.media-row--reverse .media-copy{order:initial}
  .media-visual{max-width:460px}
}

/* --------------------------------------------------------------- Cards grid */
.card-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:clamp(22px,3vw,34px)}
.book-card{
  display:flex;flex-direction:column;gap:0;background:var(--paper);
  border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;
}
.book-card__media{
  display:flex;gap:22px;padding:clamp(22px,3vw,30px);align-items:flex-start;
  background:var(--archive-white);border-bottom:1px solid var(--line);
}
.book-card__cover{width:120px;flex-shrink:0;position:relative}
.book-card__cover .cover{box-shadow:var(--shadow-soft)}
.book-card__intro{padding-top:4px}
.book-card__body{padding:clamp(22px,3vw,30px);display:flex;flex-direction:column;gap:18px;flex:1}
.book-card__title{font-size:1.55rem;line-height:1.1}
.book-card__subtitle{font-family:var(--sans);font-size:13.5px;color:var(--institution-gray);margin-top:6px;font-style:normal}
.book-card__desc{font-size:.99rem;color:var(--institution-gray);line-height:1.6}
.book-card .btn-row{margin-top:auto}
.book-card .btn{padding:13px 18px;min-height:48px;font-size:14.5px;flex:1 1 auto}

/* audiobook card */
.audio-card{
  background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);
  padding:clamp(26px,3.4vw,40px);display:flex;flex-direction:column;gap:18px;
}
.audio-card .kicker{margin-bottom:0}
.audio-card h2{font-size:1.6rem}

/* --------------------------------------------------------------- Reader bonus block */
.bonus-block{
  display:grid;grid-template-columns:0.78fr 1.22fr;gap:clamp(32px,6vw,72px);align-items:center;
}
.bonus-block .bonus-visual{max-width:360px}
@media (max-width:860px){
  .bonus-block{grid-template-columns:1fr;gap:clamp(28px,6vw,40px)}
  .bonus-block .bonus-visual{max-width:300px;margin-inline:auto;order:2}
  .bonus-block .bonus-copy{order:1}
}

/* --------------------------------------------------------------- Content note */
.content-note{
  border:1px solid var(--line);border-left:3px solid var(--bronze);
  background:var(--paper);padding:22px 26px;border-radius:0 3px 3px 0;
}
.content-note .label{
  font-family:var(--sans);font-size:11.5px;font-weight:600;letter-spacing:.18em;
  text-transform:uppercase;color:var(--bronze);display:block;margin-bottom:8px;
}
.content-note p{font-size:.96rem;color:var(--institution-gray);line-height:1.6}
.section--dark .content-note{background:rgba(237,234,226,.05);border-color:var(--on-dark-line);border-left-color:var(--bronze)}
.section--dark .content-note p{color:var(--on-dark-soft)}

/* --------------------------------------------------------------- Final CTA band */
.cta-band{text-align:center}
.cta-band .greenline{margin:0 auto 26px}
.cta-band h2{margin:0 auto 14px;max-width:18ch}
.cta-band .lede{margin:0 auto 30px;text-align:center}
.cta-band .btn-row{justify-content:center}

/* --------------------------------------------------------------- Series timeline */
.series-list{display:flex;flex-direction:column;border-top:1px solid var(--on-dark-line)}
.series-item{
  display:grid;grid-template-columns:auto 1fr auto;gap:24px;align-items:center;
  padding:26px 0;border-bottom:1px solid var(--on-dark-line);
}
.series-item .idx{font-family:var(--sans);font-size:13px;font-weight:600;letter-spacing:.1em;color:var(--bronze)}
.series-item .name{font-family:var(--serif);font-size:clamp(1.3rem,2.6vw,1.9rem);font-weight:700;color:#fff}
.series-item .state{font-family:var(--sans);font-size:13px;letter-spacing:.08em;text-transform:uppercase;color:var(--on-dark-soft)}
.series-item--soon .name{color:var(--on-dark-soft);font-style:italic;font-weight:600}
@media (max-width:600px){
  .series-item{grid-template-columns:auto 1fr;gap:14px 18px}
  .series-item .state{grid-column:2;justify-self:start}
}

/* --------------------------------------------------------------- Prose (legal) */
.prose{max-width:var(--container-narrow)}
.prose h2{font-size:clamp(1.3rem,2.4vw,1.7rem);margin:46px 0 14px}
.prose h2:first-of-type{margin-top:8px}
.prose h3{font-family:var(--sans);font-size:1.05rem;font-weight:700;margin:26px 0 8px}
.prose p{margin:0 0 16px;color:var(--institution-gray);line-height:1.7}
.prose ul{margin:0 0 18px;padding-left:0}
.prose ul li{position:relative;padding-left:24px;margin-bottom:9px;color:var(--institution-gray);line-height:1.6}
.prose ul li::before{content:"";position:absolute;left:0;top:.62em;width:12px;height:2px;background:var(--green)}
.prose a{color:var(--green-deep);text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px}
.prose strong{color:var(--ink-black)}
.prose address{font-style:normal;color:var(--institution-gray);line-height:1.7;margin:0 0 16px}
.prose .meta{font-size:13.5px;color:var(--institution-gray);letter-spacing:.02em}

/* --------------------------------------------------------------- Page intro */
.page-intro{padding-block:clamp(56px,8vw,104px) clamp(28px,4vw,48px)}
.page-intro .display,.page-intro h1{margin:0 0 20px}
.page-intro .lede{margin:0}
.page-intro .greenline{margin:0 0 28px}

/* --------------------------------------------------------------- Footer */
.footer{background:var(--night-ink);color:var(--on-dark)}
.footer-top{padding-block:clamp(54px,7vw,84px)}
.footer-grid{
  display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:clamp(32px,5vw,64px);
}
.footer-brand img{height:64px;width:auto;margin-bottom:4px}
.footer-brand p{color:var(--on-dark-soft);font-size:.96rem;max-width:34ch;margin-top:6px}
.footer-col .footer-h{
  font-family:var(--sans);font-size:12px;font-weight:600;letter-spacing:.18em;
  text-transform:uppercase;color:var(--bronze);margin:0 0 18px;
}
.footer-col ul{display:flex;flex-direction:column;gap:11px}
.footer-col a{
  font-family:var(--sans);font-size:15px;text-decoration:none;color:var(--on-dark);
  opacity:.82;transition:opacity .16s ease,color .16s ease;
}
.footer-col a:hover{opacity:1;color:#fff}
.footer-bottom{border-top:1px solid var(--on-dark-line);padding-block:28px 40px}
.footer-legal{font-size:13.5px;line-height:1.7;color:var(--on-dark-soft);max-width:62ch}
.footer-legal address{font-style:normal;display:inline}
.footer-legal a{color:var(--on-dark);text-decoration:underline;text-underline-offset:2px}
.footer-meta{
  display:flex;flex-wrap:wrap;gap:8px 22px;margin-top:18px;align-items:center;
  font-size:13px;color:var(--on-dark-soft);
}
@media (max-width:760px){
  .footer-grid{grid-template-columns:1fr 1fr;gap:36px 28px}
  .footer-brand{grid-column:1 / -1}
}
@media (max-width:460px){
  .footer-grid{grid-template-columns:1fr}
}

/* --------------------------------------------------------------- Helpers */
.stack-sm > * + *{margin-top:14px}
.stack-md > * + *{margin-top:22px}
.stack-lg > * + *{margin-top:34px}
.center{text-align:center}
.mx-auto{margin-inline:auto}
.maxw-prose{max-width:60ch}
.maxw-narrow{max-width:46ch}
.mt-0{margin-top:0}
.relief{color:var(--bronze)}