/* ============ reset ============ */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body,h1,h2,h3,h4,p,ol,ul,figure,blockquote{margin:0}
ol,ul{padding:0;list-style:none}
a{color:inherit;text-decoration:none}
img,svg{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0}
table{border-collapse:collapse;width:100%}
:focus-visible{outline:2px solid #3EC6B0;outline-offset:3px;border-radius:2px}
@media (prefers-reduced-motion: no-preference){html{scroll-behavior:smooth}}

/* ============ tokens ============ */
:root{
  --ink:#0B2B26;
  --ink-deep:#061A17;
  --ink-soft:#123A33;
  --gold:#C9A24B;
  --gold-deep:#A8842C;
  --amber:#E08A3C;
  --teal:#3EC6B0;
  --bronze:#8C7A5B;
  --coral:#E2725B;
  --paper:#F5F0E6;
  --graphite:#2A2E2B;
  --line:#4A5A5A;

  --font-head:"PingFang SC","Source Han Sans SC","Noto Sans SC","Microsoft YaHei",system-ui,sans-serif;
  --font-ui:"PingFang SC","Source Han Sans SC","Noto Sans SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Songti SC","Source Han Serif SC","Noto Serif SC",Georgia,"Times New Roman",serif;
  --font-mono:"JetBrains Mono","Roboto Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --rail-w:19rem;
  --content-max:74rem;
  --radius:2px;
  --edge:1px solid rgba(74,90,90,.5);
  --hairline:1px solid rgba(201,162,75,.28);
  --shadow-1:0 1px 0 rgba(255,255,255,.03),0 14px 30px -24px rgba(0,0,0,.95);
  --ease:cubic-bezier(.2,.7,.3,1);
  --progress:0%;
}

/* ============ base ============ */
body{
  min-height:100vh;
  background-color:var(--ink);
  background-image:
    radial-gradient(58rem 40rem at 112% -12%, rgba(62,198,176,.10), transparent 62%),
    radial-gradient(46rem 34rem at -12% 108%, rgba(201,162,75,.10), transparent 62%);
  background-repeat:no-repeat;
  background-attachment:fixed;
  color:var(--paper);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.75;
  letter-spacing:.01em;
}
main{display:block}
#main-content{display:block;scroll-margin-top:5.5rem}
@media (min-width:1024px){
  body{padding-left:var(--rail-w)}
}

/* ============ skip link ============ */
.skip-link{
  position:fixed;top:.8rem;left:.8rem;z-index:140;
  transform:translateY(-220%);
  padding:.62rem 1.05rem;
  background:var(--paper);color:var(--graphite);
  font-family:var(--font-ui);font-weight:700;font-size:.85rem;letter-spacing:.06em;
  border-radius:var(--radius);
  box-shadow:0 10px 26px -16px rgba(0,0,0,.9);
  transition:transform .18s var(--ease);
}
.skip-link:focus{transform:translateY(0)}

/* ============ header / rail ============ */
.site-header{
  position:sticky;top:0;z-index:120;
  background:linear-gradient(180deg,rgba(6,26,23,.97),rgba(11,43,38,.99));
  border-bottom:1px solid rgba(201,162,75,.35);
  backdrop-filter:blur(10px);
}
.site-header__inner{
  position:relative;
  display:flex;align-items:center;justify-content:space-between;gap:1rem;
  padding:.7rem clamp(1rem,4vw,1.6rem);
}
.rail-glow{display:none}

/* brand */
.brand{min-width:0}
.brand__link{display:flex;align-items:center;gap:.7rem}
.brand__mark{
  display:grid;place-items:center;
  width:2.5rem;height:2.5rem;flex:0 0 auto;
  font-family:var(--font-mono);font-weight:700;font-size:.72rem;letter-spacing:-.02em;
  color:#221905;
  background:linear-gradient(180deg,var(--gold),var(--gold-deep));
  border-radius:var(--radius);
  box-shadow:0 0 0 1px rgba(201,162,75,.5),0 0 22px -8px rgba(201,162,75,.85);
}
.brand__text{display:flex;flex-direction:column;line-height:1.3;min-width:0}
.brand__name{
  font-family:var(--font-head);font-weight:800;
  font-size:1.02rem;letter-spacing:.06em;color:var(--paper);
  white-space:nowrap;
}
.brand__tagline{
  font-family:var(--font-ui);font-size:.7rem;letter-spacing:-.01em;color:var(--bronze);
  white-space:nowrap;
}

/* nav toggle */
.nav-toggle{
  display:inline-flex;align-items:center;gap:.55rem;
  padding:.5rem .7rem;
  border:1px solid rgba(201,162,75,.45);border-radius:var(--radius);
  color:var(--gold);cursor:pointer;
  font-family:var(--font-ui);font-size:.76rem;font-weight:700;letter-spacing:.16em;
  transition:color .18s var(--ease),border-color .18s var(--ease),background .18s var(--ease);
}
.nav-toggle:hover{background:rgba(201,162,75,.12)}
.nav-toggle__bars{display:grid;gap:3px;width:1.05rem}
.nav-toggle__bars i{display:block;height:1.5px;background:currentColor;transition:transform .22s var(--ease),opacity .22s var(--ease)}
.site-header[data-open="true"] .nav-toggle{color:var(--teal);border-color:rgba(62,198,176,.55);background:rgba(62,198,176,.1)}
.site-header[data-open="true"] .nav-toggle__bars i:nth-child(1){transform:translateY(4.5px) rotate(45deg)}
.site-header[data-open="true"] .nav-toggle__bars i:nth-child(2){opacity:0}
.site-header[data-open="true"] .nav-toggle__bars i:nth-child(3){transform:translateY(-4.5px) rotate(-45deg)}

/* nav panel (mobile first) */
.site-nav{
  position:absolute;left:0;right:0;top:100%;
  display:grid;gap:1.1rem;
  padding:1rem clamp(1rem,4vw,1.6rem) 1.5rem;
  background:linear-gradient(180deg,rgba(7,28,25,.99),rgba(6,22,19,.99));
  border-bottom:1px solid rgba(201,162,75,.32);
  box-shadow:0 26px 40px -30px rgba(0,0,0,.95);
  max-height:0;overflow:hidden;visibility:hidden;opacity:0;
  transition:max-height .3s var(--ease),opacity .2s var(--ease),visibility .3s var(--ease);
}
.site-header[data-open="true"] .site-nav{
  max-height:min(84vh,34rem);overflow-y:auto;visibility:visible;opacity:1;
}
.site-nav__label{
  font-family:var(--font-ui);font-size:.68rem;font-weight:700;
  letter-spacing:.26em;color:var(--bronze);
}
.nav-index{display:grid;gap:.12rem}
.nav-index__item{display:block}
.nav-index__link{
  position:relative;
  display:grid;grid-template-columns:2.3rem 1fr;align-items:center;gap:.4rem;
  padding:.58rem .6rem .58rem .85rem;
  border-left:1px solid rgba(74,90,90,.5);
  font-family:var(--font-ui);font-size:.92rem;font-weight:700;letter-spacing:.02em;
  color:rgba(245,240,230,.8);
  transition:color .18s var(--ease),background .18s var(--ease),border-color .18s var(--ease);
}
.nav-index__link::after{
  content:"";position:absolute;left:-1px;top:0;bottom:0;width:1px;
  background:var(--teal);transform:scaleY(0);transform-origin:center;
  transition:transform .22s var(--ease);
}
.nav-index__num{
  font-family:var(--font-mono);font-size:.72rem;font-weight:400;
  letter-spacing:.02em;color:var(--bronze);
  transition:color .18s var(--ease);
}
.nav-index__text{display:block;min-width:0}
.nav-index__link:hover{color:var(--paper);background:rgba(62,198,176,.07)}
.nav-index__link:hover::after{transform:scaleY(1)}
.nav-index__link:hover .nav-index__num{color:var(--teal)}
.nav-index__link[aria-current="page"]{
  color:var(--gold);
  background:linear-gradient(90deg,rgba(201,162,75,.16),transparent 72%);
  border-left-color:rgba(201,162,75,.6);
}
.nav-index__link[aria-current="page"]::after{transform:scaleY(1);background:var(--gold)}
.nav-index__link[aria-current="page"] .nav-index__num{color:var(--gold)}

/* rail actions */
.rail-actions{display:grid;gap:.7rem;padding-top:1rem;border-top:var(--hairline)}
.rail-note{
  font-family:var(--font-ui);font-size:.72rem;line-height:1.65;
  letter-spacing:-.005em;color:rgba(140,122,91,.95);
}

/* progress */
.reading-progress{
  position:absolute;left:0;right:0;bottom:0;height:2px;
  background:rgba(62,198,176,.16);overflow:hidden;
}
.reading-progress__bar{
  display:block;height:100%;width:var(--progress);
  background:linear-gradient(90deg,var(--teal),var(--gold));
  transition:width .12s linear;
}

/* desktop rail */
@media (min-width:1024px){
  .site-header{
    position:fixed;inset:0 auto 0 0;width:var(--rail-w);
    border-bottom:0;border-right:1px solid rgba(201,162,75,.3);
    background:linear-gradient(165deg,#06201C 0%,#0B2B26 52%,#08211D 100%);
    backdrop-filter:none;
  }
  .site-header__inner{
    flex-direction:column;align-items:stretch;justify-content:flex-start;gap:0;
    height:100%;padding:1.9rem 1.5rem 1.6rem;
    overflow-y:auto;
  }
  .rail-glow{
    display:block;position:absolute;inset:0;pointer-events:none;
    background:
      radial-gradient(18rem 14rem at 8% 100%,rgba(62,198,176,.16),transparent 70%),
      radial-gradient(14rem 12rem at 100% 0%,rgba(201,162,75,.12),transparent 72%);
  }
  .brand{position:relative;z-index:1}
  .nav-toggle{display:none}
  .site-nav{
    position:static;flex:1 1 auto;display:flex;flex-direction:column;gap:1.35rem;
    max-height:none;overflow:visible;visibility:visible;opacity:1;
    margin-top:1.7rem;padding:1.6rem 0 0;
    background:none;border:0;border-top:var(--hairline);box-shadow:none;
  }
  .rail-actions{margin-top:auto}
  .reading-progress{
    left:auto;right:0;top:0;bottom:0;width:2px;height:auto;
    background:rgba(62,198,176,.12);
  }
  .reading-progress__bar{
    width:100%;height:var(--progress);
    background:linear-gradient(180deg,var(--teal),var(--gold));
    transition:height .12s linear;
  }
}

/* ============ buttons ============ */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.5rem;
  padding:.7rem 1.05rem;
  border:1px solid transparent;border-radius:var(--radius);
  font-family:var(--font-ui);font-weight:700;font-size:.85rem;letter-spacing:.08em;
  cursor:pointer;
  transition:background .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease),transform .18s var(--ease),box-shadow .22s var(--ease);
}
.btn--gold{
  background:linear-gradient(180deg,var(--gold),var(--gold-deep));
  color:#221905;
  box-shadow:0 12px 26px -20px rgba(201,162,75,.95);
}
.btn--gold:hover{background:linear-gradient(180deg,#D9B45E,#B8912F);transform:translateY(-1px)}
.btn--ghost{border-color:rgba(62,198,176,.5);color:var(--teal);background:rgba(62,198,176,.07)}
.btn--ghost:hover{border-color:var(--teal);background:rgba(62,198,176,.16)}
.btn--bronze{border-color:rgba(140,122,91,.6);color:var(--bronze);background:transparent}
.btn--bronze:hover{color:var(--paper);border-color:var(--bronze);background:rgba(140,122,91,.14)}
.btn--coral{border-color:rgba(226,114,91,.5);color:var(--coral);background:rgba(226,114,91,.08)}
.btn--coral:hover{background:rgba(226,114,91,.18)}

/* ============ chips ============ */
.chip{
  display:inline-flex;align-items:center;gap:.4rem;
  padding:.28rem .62rem;border:1px solid;border-radius:999px;
  font-family:var(--font-ui);font-size:.7rem;font-weight:700;letter-spacing:.08em;
}
.chip--gold{border-color:rgba(201,162,75,.5);color:var(--gold);background:rgba(201,162,75,.1)}
.chip--teal{border-color:rgba(62,198,176,.5);color:var(--teal);background:rgba(62,198,176,.1)}
.chip--bronze{border-color:rgba(140,122,91,.55);color:var(--bronze);background:rgba(140,122,91,.1)}
.chip--coral{border-color:rgba(226,114,91,.55);color:var(--coral);background:rgba(226,114,91,.1)}

/* ============ footer ============ */
.site-footer{
  margin-top:clamp(3rem,7vw,5.5rem);
  padding:clamp(2rem,5vw,3.5rem) clamp(1rem,4vw,2rem) clamp(1.4rem,3vw,2rem);
  border-top:1px solid rgba(201,162,75,.3);
  background:linear-gradient(180deg,rgba(6,26,23,.35),rgba(4,17,15,.95));
}
.site-footer__inner{max-width:var(--content-max);margin-inline:auto}
.footer-grid{display:grid;grid-template-columns:1fr;gap:2rem}
.footer-brand__mark{
  font-family:var(--font-head);font-weight:800;font-size:1.12rem;letter-spacing:.07em;
  color:var(--paper);
}
.footer-brand__line{
  margin-top:.4rem;
  font-family:var(--font-ui);font-size:.76rem;font-weight:700;
  letter-spacing:-.01em;color:var(--gold);
}
.footer-brand__note{
  margin-top:.9rem;max-width:34rem;
  font-size:.94rem;line-height:1.8;color:rgba(245,240,230,.72);
}
.footer-nav{display:grid;align-content:start}
.footer-col__title{
  margin-bottom:.85rem;
  font-family:var(--font-ui);font-size:.7rem;font-weight:700;
  letter-spacing:.24em;color:var(--bronze);
}
.footer-list{display:grid;gap:.55rem}
.footer-list a{
  display:inline-block;
  font-family:var(--font-ui);font-size:.9rem;letter-spacing:.02em;
  color:rgba(245,240,230,.84);
  border-bottom:1px solid transparent;padding-bottom:.12rem;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.footer-list a:hover{color:var(--gold);border-bottom-color:rgba(201,162,75,.6)}
.footer-list--plain li{
  font-family:var(--font-mono);font-size:.82rem;letter-spacing:.01em;
  color:rgba(245,240,230,.78);word-break:break-all;
}
.footer-contact{display:grid;align-content:start}
.footer-contact__meta{
  margin-top:.7rem;
  font-family:var(--font-ui);font-size:.82rem;line-height:1.7;
  color:rgba(245,240,230,.62);
}
.footer-contact__meta .chip{margin-top:.2rem}
.footer-base{
  margin-top:2.2rem;padding-top:1.2rem;
  border-top:var(--edge);
  display:flex;flex-wrap:wrap;gap:.6rem 1.8rem;
  align-items:baseline;justify-content:space-between;
  font-family:var(--font-ui);font-size:.78rem;color:rgba(245,240,230,.6);
}
.footer-base__copy{letter-spacing:.02em}
.footer-base__contact{
  font-family:var(--font-mono);letter-spacing:.01em;
  color:rgba(140,122,91,.95);
}
@media (min-width:768px){
  .footer-grid{grid-template-columns:1.7fr 1fr 1.2fr;gap:2.4rem}
}
@media (min-width:1024px){
  .footer-grid{grid-template-columns:2fr 1fr 1.3fr;gap:3rem}
}

/* ============ content layout ============ */
.wrap{
  width:100%;max-width:var(--content-max);margin-inline:auto;
  padding-inline:clamp(1rem,4vw,2rem);
}
.page{padding-block:clamp(1.8rem,5vw,3.5rem) 0}
.section{margin-top:clamp(2.5rem,6vw,4.5rem)}
.section__head{display:grid;gap:.5rem;max-width:48rem;margin-bottom:1.5rem}
.section__eyebrow{
  font-family:var(--font-mono);font-size:.72rem;letter-spacing:.22em;
  text-transform:uppercase;color:var(--teal);
}
.section__title{
  font-family:var(--font-head);font-weight:800;
  font-size:clamp(1.6rem,3.4vw,2.2rem);line-height:1.22;letter-spacing:.01em;
  color:var(--paper);
}
.section__title--stable{letter-spacing:.03em}
.section__title--archive{letter-spacing:-.01em;color:rgba(245,240,230,.86)}
.section__lead{max-width:44rem;font-size:1.02rem;color:rgba(245,240,230,.74)}
.lede{font-size:clamp(1.05rem,2.2vw,1.2rem);line-height:1.85;color:rgba(245,240,230,.85)}

/* ============ grids ============ */
.grid{display:grid;gap:clamp(1rem,2.5vw,1.6rem)}
.grid--2,.grid--3,.grid--split,.grid--offset{grid-template-columns:1fr}
@media (min-width:768px){
  .grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
  .grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
}
@media (min-width:1024px){
  .grid--split{grid-template-columns:1.5fr 1fr}
  .grid--offset{grid-template-columns:1fr 1.18fr;align-items:start}
}

/* ============ cards ============ */
.card{
  position:relative;display:grid;gap:.6rem;
  padding:1.15rem 1.2rem 1.3rem;
  border:1px solid rgba(74,90,90,.5);border-radius:var(--radius);
  background:linear-gradient(180deg,rgba(245,240,230,.05),rgba(245,240,230,.015));
  box-shadow:var(--shadow-1);
  transition:transform .22s var(--ease),border-color .22s var(--ease),box-shadow .22s var(--ease);
}
.card:hover{
  transform:translateY(-2px);
  border-color:rgba(62,198,176,.55);
  box-shadow:0 20px 36px -28px rgba(62,198,176,.85);
}
.card--stable{
  border-color:rgba(201,162,75,.45);
  background:linear-gradient(180deg,rgba(201,162,75,.1),rgba(245,240,230,.02));
}
.card--archive{
  border-color:rgba(140,122,91,.45);
  background:linear-gradient(180deg,rgba(140,122,91,.08),rgba(245,240,230,.015));
}
.card__index{
  font-family:var(--font-mono);font-size:.7rem;letter-spacing:.16em;
  color:var(--bronze);
}
.card__title{
  font-family:var(--font-head);font-weight:800;font-size:1.15rem;line-height:1.35;
  color:var(--paper);
}
.card__body{font-size:.95rem;line-height:1.8;color:rgba(245,240,230,.72)}
.card__meta{
  display:flex;flex-wrap:wrap;gap:.5rem;
  font-family:var(--font-ui);font-size:.74rem;color:var(--bronze);
}
.card__link{position:absolute;inset:0;z-index:1;border-radius:var(--radius)}

/* ============ aside note ============ */
.aside-note{
  display:grid;gap:.5rem;
  padding:1rem 1.1rem;
  border-left:2px solid var(--bronze);
  background:linear-gradient(90deg,rgba(140,122,91,.13),transparent 82%);
  font-size:.92rem;line-height:1.8;color:rgba(245,240,230,.8);
}
.aside-note--teal{border-left-color:var(--teal);background:linear-gradient(90deg,rgba(62,198,176,.13),transparent 82%)}
.aside-note--coral{border-left-color:var(--coral);background:linear-gradient(90deg,rgba(226,114,91,.14),transparent 82%)}
.aside-note__title{
  font-family:var(--font-ui);font-weight:700;font-size:.86rem;letter-spacing:.06em;
  color:var(--paper);
}

/* ============ breadcrumb ============ */
.breadcrumb{margin-bottom:1.25rem}
.breadcrumb__list{
  display:flex;flex-wrap:wrap;align-items:center;gap:.5rem;
  font-family:var(--font-ui);font-size:.76rem;color:var(--bronze);
}
.breadcrumb__item{display:inline-flex;align-items:center;gap:.5rem}
.breadcrumb__item + .breadcrumb__item::before{content:"/";color:rgba(140,122,91,.7)}
.breadcrumb__link{
  color:rgba(245,240,230,.74);
  border-bottom:1px solid transparent;padding-bottom:.1rem;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.breadcrumb__link:hover{color:var(--gold);border-bottom-color:rgba(201,162,75,.6)}
.breadcrumb__item[aria-current="page"]{color:var(--paper)}

/* ============ compare table ============ */
.compare-wrap{
  overflow-x:auto;border:1px solid rgba(74,90,90,.45);border-radius:var(--radius);
  background:rgba(6,26,23,.45);
}
.compare{width:100%;min-width:34rem;font-size:.92rem}
.compare caption{
  caption-side:top;text-align:left;padding:.9rem 1rem .2rem;
  font-family:var(--font-ui);font-size:.74rem;letter-spacing:.16em;color:var(--bronze);
}
.compare th,.compare td{
  padding:.8rem 1rem;text-align:left;vertical-align:top;
  border-bottom:1px solid rgba(74,90,90,.42);
}
.compare thead th{
  font-family:var(--font-ui);font-size:.8rem;letter-spacing:.06em;
  color:var(--gold);border-bottom-color:rgba(201,162,75,.5);
}
.compare tbody tr{transition:background .18s var(--ease)}
.compare tbody tr:hover{background:rgba(62,198,176,.06)}
.compare tbody tr:last-child th,.compare tbody tr:last-child td{border-bottom:0}
.compare__key{font-family:var(--font-ui);font-weight:700;color:var(--paper);white-space:nowrap}
.compare__num{font-family:var(--font-mono);color:var(--teal)}

/* ============ segmented control ============ */
.seg{
  display:inline-flex;border:1px solid rgba(74,90,90,.55);border-radius:var(--radius);
  overflow:hidden;
}
.seg__btn{
  padding:.45rem .9rem;cursor:pointer;
  font-family:var(--font-ui);font-size:.78rem;font-weight:700;letter-spacing:.06em;
  color:rgba(245,240,230,.72);background:transparent;
  transition:background .18s var(--ease),color .18s var(--ease);
}
.seg__btn:hover{color:var(--paper);background:rgba(245,240,230,.05)}
.seg__btn[aria-selected="true"]{background:rgba(201,162,75,.18);color:var(--gold)}

/* ============ entry link ============ */
.entry-link{
  display:inline-flex;align-items:center;gap:.45rem;
  font-family:var(--font-ui);font-weight:700;font-size:.86rem;letter-spacing:.06em;
  color:var(--teal);
  border-bottom:1px solid rgba(62,198,176,.35);padding-bottom:.15rem;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.entry-link:hover{color:var(--gold);border-bottom-color:rgba(201,162,75,.6)}
.entry-link--gold{color:var(--gold);border-bottom-color:rgba(201,162,75,.4)}
.entry-link--gold:hover{color:var(--paper);border-bottom-color:rgba(245,240,230,.55)}
.entry-link--bronze{color:var(--bronze);border-bottom-color:rgba(140,122,91,.45)}
.entry-link--bronze:hover{color:var(--gold);border-bottom-color:rgba(201,162,75,.6)}

/* ============ figure / image containers ============ */
.figure{margin:0;display:grid;gap:.65rem}
.figure__frame{
  position:relative;overflow:hidden;
  aspect-ratio:16/9;
  border:1px solid rgba(74,90,90,.5);border-radius:var(--radius);
  background:linear-gradient(140deg,#08211D,#0B2B26 58%,#123A33);
}
.figure__frame::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:linear-gradient(180deg,rgba(6,26,23,0),rgba(6,26,23,.55));
}
.figure__img{
  width:100%;height:100%;object-fit:cover;
  filter:saturate(.92) contrast(1.04);
}
.figure__caption{
  font-family:var(--font-ui);font-size:.76rem;line-height:1.65;
  color:var(--bronze);
}
.figure--wide .figure__frame{aspect-ratio:21/9}
.figure--tall .figure__frame{aspect-ratio:3/4}
.figure--square .figure__frame{aspect-ratio:1/1}
.figure--phone .figure__frame{aspect-ratio:9/19}

/* ============ toc ============ */
.toc{display:grid;gap:.4rem}
.toc__link{
  display:block;padding:.35rem 0 .35rem .9rem;
  border-left:1px solid rgba(74,90,90,.5);
  font-family:var(--font-ui);font-size:.84rem;letter-spacing:.02em;
  color:rgba(245,240,230,.7);
  transition:color .18s var(--ease),border-color .18s var(--ease),background .18s var(--ease);
}
.toc__link:hover{color:var(--paper);border-left-color:rgba(62,198,176,.7)}
.toc__link[data-active="true"]{
  color:var(--gold);border-left-color:var(--gold);
  background:linear-gradient(90deg,rgba(201,162,75,.12),transparent 80%);
}

/* ============ section states / reveal ============ */
[data-section]{scroll-margin-top:5.5rem}
[data-section][data-current="true"] .section__eyebrow{color:var(--gold)}
[data-reveal]{
  opacity:0;transform:translateY(10px);
  transition:opacity .55s var(--ease),transform .55s var(--ease);
}
[data-reveal][data-visible="true"]{opacity:1;transform:none}

/* ============ to top ============ */
.to-top{
  position:fixed;right:1.1rem;bottom:1.1rem;z-index:100;
  width:2.6rem;height:2.6rem;display:grid;place-items:center;
  border:1px solid rgba(201,162,75,.45);border-radius:50%;
  background:rgba(6,26,23,.92);color:var(--gold);
  font-family:var(--font-mono);font-size:1rem;cursor:pointer;
  opacity:0;visibility:hidden;transform:translateY(10px);
  transition:opacity .25s var(--ease),transform .25s var(--ease),visibility .25s var(--ease),border-color .2s var(--ease);
}
.to-top[data-show="true"]{opacity:1;visibility:visible;transform:none}
.to-top:hover{border-color:var(--teal);color:var(--teal)}

/* ============ reduced motion ============ */
@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{
    animation-duration:.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.01ms !important;
    scroll-behavior:auto !important;
  }
  [data-reveal]{opacity:1;transform:none}
}