/* =====================================================================
   davinci254254’s Tech Den — clean product-page style
   ===================================================================== */

:root {
  color-scheme: light;
  --bg: #ffffff;
  --bg-2: #f5f5f7;
  --card: #ffffff;
  --text: #1d1d1f;
  --text-2: #6e6e73;
  --text-3: #86868b;
  --rule: #d2d2d7;
  --link: #0066cc;
  --btn: #0071e3;
  --btn-hover: #0077ed;
  --eyebrow: #bf4800;
  --chip: #e8e8ed;
  --nav-bg: rgba(250, 250, 252, .8);
  --nav-ink: rgba(0, 0, 0, .8);
  --dark: #000000;
  --dark-card: #1d1d1f;
  --dark-text: #f5f5f7;
  --dark-text-2: #86868b;
  --dark-link: #2997ff;
  --logo-ink: #ffffff;
  --shadow: 0 2px 6px rgba(0, 0, 0, .04), 0 10px 30px rgba(0, 0, 0, .06);
  --shadow-hover: 0 4px 10px rgba(0, 0, 0, .06), 0 22px 50px rgba(0, 0, 0, .12);
  --grad: linear-gradient(90deg, #0090f7 0%, #ba62fc 38%, #f2416b 72%, #f55600 100%);

  --font: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text', 'Inter', 'Helvetica Neue', Helvetica, Arial, 'PingFang SC', sans-serif;
  --mono: ui-monospace, 'SF Mono', SFMono-Regular, Menlo, monospace;
  --ease: cubic-bezier(.28, .11, .32, 1);
  --max: 980px;
  --gutter: max(22px, env(safe-area-inset-left));
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #000000; --bg-2: #161617; --card: #1d1d1f;
    --text: #f5f5f7; --text-2: #a1a1a6; --text-3: #86868b; --rule: #424245;
    --link: #2997ff; --eyebrow: #ff791b; --chip: #2a2a2d;
    --nav-bg: rgba(22, 22, 23, .8); --nav-ink: rgba(255, 255, 255, .8);
    --dark: #0d0d0e; --logo-ink: #000000;
    --shadow: 0 0 0 1px rgba(255,255,255,.06); --shadow-hover: 0 0 0 1px rgba(255,255,255,.14), 0 22px 50px rgba(0,0,0,.6);
  }
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #000000; --bg-2: #161617; --card: #1d1d1f;
  --text: #f5f5f7; --text-2: #a1a1a6; --text-3: #86868b; --rule: #424245;
  --link: #2997ff; --eyebrow: #ff791b; --chip: #2a2a2d;
  --nav-bg: rgba(22, 22, 23, .8); --nav-ink: rgba(255, 255, 255, .8);
  --dark: #0d0d0e; --logo-ink: #000000;
  --shadow: 0 0 0 1px rgba(255,255,255,.06); --shadow-hover: 0 0 0 1px rgba(255,255,255,.14), 0 22px 50px rgba(0,0,0,.6);
}

/* ------------------------------------------------------------- base */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 100px; }
body {
  margin: 0; min-height: 100vh; display: flex; flex-direction: column;
  background: var(--bg); color: var(--text);
  font: 400 17px/1.47 var(--font); letter-spacing: -.022em;
  -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; font-synthesis: none;
  overflow-x: hidden;
}
body.is-grey { background: var(--bg-2); }
main { flex: 1; }
a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }
cite { font-style: italic; }
button { font: inherit; color: inherit; letter-spacing: inherit; }
:focus-visible { outline: 2px solid var(--btn); outline-offset: 3px; border-radius: 6px; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--text); color: var(--bg); padding: 8px 14px; border-radius: 8px; z-index: 200; }
.skip:focus { left: 8px; }
.nowrap { white-space: nowrap; }
.muted { color: var(--text-3); }
.grad { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; -webkit-text-fill-color: transparent; }

.eyebrow { margin: 0 0 8px; font-size: 17px; font-weight: 600; letter-spacing: -.02em; color: var(--eyebrow); }
.eyebrow--center { text-align: center; }
.eyebrow a:hover { text-decoration: underline; }

/* buttons & links */
.ctas { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 14px 34px; margin: 0; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; min-width: 28px;
  padding: 11px 22px; border-radius: 980px; background: var(--btn); color: #fff;
  font-size: 17px; font-weight: 400; line-height: 1.18; letter-spacing: -.022em; white-space: nowrap;
  transition: background .2s;
}
.btn:hover { background: var(--btn-hover); }
.btn--sm { padding: 4px 11px; font-size: 12px; letter-spacing: -.01em; }
.btn--lg { padding: 14px 28px; font-size: 17px; }
.link { color: var(--link); font-size: 17px; white-space: nowrap; }
.link:hover, a:hover > .ctas .link { text-decoration: underline; }
.chev { display: inline-block; margin-left: 2px; font-size: 1.15em; line-height: 1; transform: translateY(1px); }

/* ------------------------------------------------------------- global nav */
.gnav { position: sticky; top: 0; z-index: 60; height: 48px; background: var(--nav-bg); backdrop-filter: saturate(180%) blur(20px); -webkit-backdrop-filter: saturate(180%) blur(20px); }
.gnav__in { max-width: 1024px; height: 100%; margin: 0 auto; padding: 0 var(--gutter); display: flex; align-items: center; gap: 24px; }
.gnav__brand { display: inline-flex; align-items: center; gap: 8px; font-size: 14px; font-weight: 600; letter-spacing: -.01em; color: var(--text); white-space: nowrap; flex-shrink: 0; }
.logo { width: 20px; height: 20px; color: var(--text); transition: transform .4s var(--ease); }
.gnav__brand:hover .logo { transform: rotate(-8deg); }
.gnav__links { flex: 1; display: flex; justify-content: flex-end; gap: 30px; }
.gnav__links a { font-size: 12.5px; letter-spacing: -.01em; color: var(--nav-ink); opacity: .9; transition: color .2s, opacity .2s; }
.gnav__links a:hover, .gnav__links a[aria-current] { color: var(--text); opacity: 1; }
.gnav__links a[aria-current] { font-weight: 600; }
.gnav__theme { width: 32px; height: 32px; display: grid; place-items: center; border: 0; background: none; cursor: pointer; color: var(--nav-ink); border-radius: 50%; margin-right: -6px; }
.gnav__theme svg { width: 16px; height: 16px; }
.gnav__theme:hover { color: var(--text); background: var(--chip); }

/* local nav (product sub-nav) */
.lnav { position: sticky; top: 48px; z-index: 55; height: 52px; background: var(--nav-bg); backdrop-filter: saturate(180%) blur(20px); -webkit-backdrop-filter: saturate(180%) blur(20px); border-bottom: 1px solid color-mix(in srgb, var(--rule) 70%, transparent); }
.lnav__in { max-width: 1024px; height: 100%; margin: 0 auto; padding: 0 var(--gutter); display: flex; align-items: center; justify-content: space-between; }
.lnav__title { font-size: 21px; font-weight: 600; letter-spacing: .011em; }
.lnav__links { display: flex; align-items: center; gap: 24px; font-size: 12px; }
.lnav__links a:not(.btn) { color: var(--nav-ink); }
.lnav__links a:not(.btn):hover { color: var(--link); }

/* ------------------------------------------------------------- hero */
.hero { text-align: center; padding: 64px var(--gutter) 0; overflow: hidden; }
.hero__eyebrow { margin: 0 0 6px; font-size: 21px; font-weight: 600; color: var(--eyebrow); letter-spacing: .01em; }
.hero__title { margin: 0 auto; max-width: 14ch; font-size: clamp(44px, 7.4vw, 88px); line-height: 1.04; font-weight: 600; letter-spacing: -.028em; }
.hero__sub { margin: 18px auto 26px; max-width: 30ch; font-size: clamp(21px, 2.3vw, 28px); line-height: 1.18; font-weight: 400; letter-spacing: .004em; }
.hero__sub cite { font-style: normal; font-weight: 500; }
.hero__stage { position: relative; display: grid; place-items: center; padding: 64px 0 80px; }
.stage-shadow { position: absolute; bottom: 52px; left: 50%; width: min(440px, 70vw); height: 40px; transform: translateX(-46%); background: radial-gradient(ellipse, rgba(0, 0, 0, .28), transparent 68%); filter: blur(8px); z-index: -1; }

/* ------------------------------------------------------------- bands */
.band { padding: clamp(80px, 10vw, 128px) var(--gutter); background: var(--bg); }
.band--dark { background: var(--dark); color: var(--dark-text); --text-3: var(--dark-text-2); --link: var(--dark-link); }
.band--grey { background: var(--bg-2); }
.band--tight { padding: 12px; }
.band__in { max-width: var(--max); margin: 0 auto; }
.band__title { margin: 0 auto; text-align: center; font-size: clamp(40px, 5.6vw, 64px); line-height: 1.06; font-weight: 600; letter-spacing: -.025em; }
.band__sub { margin: 20px auto 0; max-width: 34em; text-align: center; font-size: clamp(19px, 1.9vw, 21px); line-height: 1.38; color: var(--text-3); letter-spacing: .011em; }
.band--dark .eyebrow { color: #ff791b; }

/* ------------------------------------------------------------- 3D book */
.book3d { --w: clamp(200px, 22vw, 260px); --t: 32px; display: block; width: var(--w); aspect-ratio: 5 / 7; perspective: 1600px; color: var(--ink); }
.book3d--hero { --w: clamp(230px, 30vw, 340px); --t: 40px; }
.book3d__body { position: relative; width: 100%; height: 100%; transform-style: preserve-3d; transform: rotateY(-26deg) rotateX(3deg); transition: transform 1s var(--ease); }
.book3d:hover .book3d__body, .book3d:focus-visible .book3d__body { transform: rotateY(-10deg) rotateX(1deg) translateY(-8px); }
.book3d__cover, .book3d__back { position: absolute; inset: 0; border-radius: 3px 10px 10px 3px; }
.book3d__cover {
  transform: translateZ(calc(var(--t) / 2)); overflow: hidden;
  display: flex; flex-direction: column; padding: 11% 11% 9% 14%; text-align: left; letter-spacing: 0;
  background:
    linear-gradient(90deg, rgba(0,0,0,.34) 0, rgba(255,255,255,.12) 2.4%, rgba(0,0,0,.12) 3.6%, transparent 7%),
    linear-gradient(160deg, rgba(255,255,255,.14), transparent 40%, rgba(0,0,0,.22)),
    var(--cover);
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.06);
}
.book3d__cover::after { content: ''; position: absolute; inset: 5.5% 6% 5.5% 9%; border: 1px solid color-mix(in srgb, var(--ink) 45%, transparent); border-radius: 2px; pointer-events: none; }
.book3d__back { transform: translateZ(calc(var(--t) / -2)); background: color-mix(in srgb, var(--cover) 70%, #000); box-shadow: 34px 40px 70px rgba(0, 0, 0, .28); }
.book3d__pages { position: absolute; top: 1.6%; bottom: 1.6%; width: var(--t); left: calc(100% - var(--t) / 2 - 3px); transform: rotateY(90deg); background: repeating-linear-gradient(90deg, #f6f2e8 0 1.5px, #ddd4c2 1.5px 2.5px), #f1ebdd; box-shadow: inset 0 0 12px rgba(0,0,0,.22); }
.cover__kicker { position: relative; z-index: 1; font: 600 9px/1.3 var(--font); letter-spacing: .18em; text-transform: uppercase; opacity: .82; }
.cover__art { position: relative; z-index: 1; width: 100%; margin: auto 0 14%; }
.cover__title { position: relative; z-index: 1; font-size: clamp(19px, 2.1vw, 27px); line-height: 1.06; font-weight: 600; letter-spacing: -.02em; text-wrap: balance; }
.book3d--hero .cover__title { font-size: clamp(22px, 2.6vw, 32px); }
.cover__by { position: relative; z-index: 1; margin-top: 10%; font-size: 11.5px; line-height: 1.35; opacity: .78; letter-spacing: 0; }

/* ------------------------------------------------------------- playground */
.playground { margin: 56px 0 0; display: grid; grid-template-columns: minmax(0, 1fr) 300px; background: var(--dark-card); border-radius: 28px; overflow: hidden; text-align: left; --pg-accent: #2997ff; }
.playground__chart { padding: 28px 16px 18px 22px; min-width: 0; }
.playground__chart svg { width: 100%; height: auto; overflow: visible; touch-action: pan-y; cursor: crosshair; }
.playground__controls { padding: 28px; display: flex; flex-direction: column; gap: 22px; background: rgba(255,255,255,.03); }
.playground__cap { grid-column: 1 / -1; padding: 16px 28px 20px; font-size: 13px; color: var(--dark-text-2); border-top: 1px solid rgba(255,255,255,.08); letter-spacing: -.01em; }
.pg-grid line { stroke: rgba(255,255,255,.08); }
.pg-axis text { fill: var(--dark-text-2); font: 500 11px var(--font); letter-spacing: 0; }
.pg-payoff { fill: none; stroke: rgba(255,255,255,.45); stroke-width: 1.5; stroke-dasharray: 5 5; }
.pg-value { fill: none; stroke: var(--pg-accent); stroke-width: 3; stroke-linejoin: round; stroke-linecap: round; }
.pg-area { fill: url(#pg-fill); }
.pg-stop { stop-color: var(--pg-accent); }
.pg-strike { stroke: rgba(255,255,255,.18); stroke-dasharray: 2 4; }
.pg-cursor line { stroke: rgba(255,255,255,.3); }
.pg-cursor circle { fill: #fff; stroke: var(--pg-accent); stroke-width: 3; }
.pg-cursor text { fill: var(--dark-text); font: 600 12px var(--font); letter-spacing: 0; }
.seg { display: grid; grid-template-columns: 1fr 1fr; padding: 3px; border-radius: 12px; background: rgba(255,255,255,.08); }
.seg button { border: 0; background: transparent; padding: 8px 0; border-radius: 9px; cursor: pointer; font-weight: 500; font-size: 14px; color: var(--dark-text-2); transition: background .25s, color .25s; }
.seg button[aria-pressed="true"] { background: #636366; color: #fff; box-shadow: 0 3px 8px rgba(0,0,0,.2); }
.slider { display: grid; gap: 10px; font-size: 14px; color: var(--dark-text-2); }
.slider > span { display: flex; justify-content: space-between; }
.slider output { font-weight: 600; color: var(--dark-text); font-variant-numeric: tabular-nums; }
.slider input { -webkit-appearance: none; appearance: none; width: 100%; height: 22px; background: transparent; cursor: pointer; margin: 0; }
.slider input::-webkit-slider-runnable-track { height: 4px; border-radius: 4px; background: linear-gradient(90deg, var(--pg-accent) var(--p, 50%), rgba(255,255,255,.16) var(--p, 50%)); }
.slider input::-moz-range-track { height: 4px; border-radius: 4px; background: rgba(255,255,255,.16); }
.slider input::-moz-range-progress { height: 4px; border-radius: 4px; background: var(--pg-accent); }
.slider input::-webkit-slider-thumb { -webkit-appearance: none; width: 22px; height: 22px; margin-top: -9px; border-radius: 50%; background: #fff; border: 0; box-shadow: 0 1px 4px rgba(0,0,0,.35); transition: transform .2s; }
.slider input::-moz-range-thumb { width: 22px; height: 22px; border-radius: 50%; background: #fff; border: 0; box-shadow: 0 1px 4px rgba(0,0,0,.35); }
.slider input:active::-webkit-slider-thumb { transform: scale(1.12); }
.readout { margin: auto 0 0; display: grid; }
.readout > div { display: flex; justify-content: space-between; align-items: baseline; padding: 10px 0; border-top: 1px solid rgba(255,255,255,.08); }
.readout dt { font-size: 14px; color: var(--dark-text-2); }
.readout dt small { font-size: inherit; }
.readout dd { margin: 0; font-size: 24px; font-weight: 600; letter-spacing: -.02em; font-variant-numeric: tabular-nums; color: var(--dark-text); }

/* ------------------------------------------------------------- stats & features */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin: 64px 0 56px; text-align: center; }
.stats dt { font-size: clamp(44px, 5.4vw, 64px); line-height: 1.05; font-weight: 700; letter-spacing: -.03em; padding-bottom: 4px; }
.stats dd { margin: 6px 0 0; font-size: 17px; font-weight: 600; color: var(--text-2); }
.stats > div:nth-child(2) dt { background-position: 33% 0; }
.stats dt.grad { background-size: 400% 100%; }
.stats > div:nth-child(1) dt { background-position: 0 0; }
.stats > div:nth-child(3) dt { background-position: 66% 0; }
.stats > div:nth-child(4) dt { background-position: 100% 0; }
.features { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.feature-card { background: var(--bg-2); border-radius: 18px; padding: 28px 24px 30px; text-align: left; }
.band--grey .feature-card { background: var(--card); }
.feature-card__icon { display: block; width: 40px; height: 40px; color: var(--btn); margin-bottom: 18px; }
.feature-card p { margin: 0; font-size: 19px; line-height: 1.26; font-weight: 600; letter-spacing: -.02em; }

/* ------------------------------------------------------------- promo grid */
.promo-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.promo { position: relative; display: flex; flex-direction: column; align-items: center; text-align: center; min-height: 520px; padding: 56px 32px; border-radius: 22px; overflow: hidden; transition: transform .5s var(--ease); }
.promo:hover { transform: scale(1.008); }
.promo--light { background: var(--bg-2); }
.promo--dark { background: var(--dark); color: var(--dark-text); --text-3: var(--dark-text-2); --link: var(--dark-link); }
.promo .eyebrow { font-size: 14px; }
.promo__title { margin: 0; font-size: clamp(32px, 3.6vw, 44px); line-height: 1.08; font-weight: 600; letter-spacing: -.025em; text-wrap: balance; max-width: 16ch; }
.promo__sub { margin: 12px 0 18px; max-width: 30ch; font-size: 19px; line-height: 1.32; color: var(--text-3); }
.promo:hover .link { text-decoration: underline; }
.promo--light::after { /* decorative: printed page */
  content: ''; position: absolute; left: 50%; bottom: -60px; width: 300px; height: 210px; transform: translateX(-50%) rotate(-4deg); border-radius: 14px; background:
    repeating-linear-gradient(180deg, transparent 0 22px, var(--rule) 22px 23px) 28px 40px / calc(100% - 56px) 100% no-repeat,
    linear-gradient(var(--text) 0 0) 28px 22px / 46% 7px no-repeat, var(--card);
  box-shadow: var(--shadow-hover); transition: transform .8s var(--ease);
}
.promo--light:hover::after { transform: translateX(-50%) rotate(-1deg) translateY(-8px); }
.promo__shelf { position: absolute; bottom: 0; left: 50%; transform: translateX(-50%); display: flex; align-items: flex-end; gap: 6px; height: 200px; padding: 0 14px 14px; border-bottom: 6px solid #2c2c2e; }
.promo__shelf i { display: block; width: 34px; border-radius: 3px 3px 1px 1px; transition: transform .6s var(--ease); }
.promo__shelf i:nth-child(1) { height: 160px; background: #5c1e17; }
.promo__shelf i:nth-child(2) { height: 132px; width: 26px; border: 1.5px dashed #48484a; }
.promo__shelf i:nth-child(3) { height: 148px; border: 1.5px dashed #48484a; }
.promo__shelf i:nth-child(4) { height: 118px; width: 22px; border: 1.5px dashed #3a3a3c; transform-origin: bottom left; transform: rotate(8deg); }
.promo--dark:hover .promo__shelf i:nth-child(1) { transform: translateY(-10px); }

/* ------------------------------------------------------------- page heads */
.page-head { max-width: var(--max); margin: 0 auto; padding: clamp(56px, 8vw, 96px) var(--gutter) 40px; }
.page-head--center { text-align: center; }
.page-title { margin: 0; font-size: clamp(44px, 6.8vw, 80px); line-height: 1.05; font-weight: 600; letter-spacing: -.03em; }
.page-sub { margin: 14px 0 0; max-width: 32em; font-size: clamp(19px, 2vw, 24px); line-height: 1.3; color: var(--text-2); letter-spacing: .005em; }
.page-head--center .page-sub { margin-inline: auto; }

.chips { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 36px; }
.chip { display: inline-flex; gap: 8px; align-items: center; padding: 8px 18px; border-radius: 980px; border: 0; background: var(--chip); cursor: pointer; font-size: 14px; font-weight: 500; color: var(--text); transition: background .2s, color .2s; }
.chip span { color: var(--text-3); font-weight: 400; }
.chip:hover { background: color-mix(in srgb, var(--chip) 80%, var(--text) 8%); }
.chip[aria-pressed="true"] { background: var(--text); color: var(--bg); }
.chip[aria-pressed="true"] span { color: color-mix(in srgb, var(--bg) 70%, transparent); }

/* ------------------------------------------------------------- tiles (writing) */
.tiles-wrap { max-width: var(--max); margin: 0 auto; padding: 0 var(--gutter) 40px; }
.tiles { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.tiles--two { grid-template-columns: repeat(2, 1fr); }
.post-tile[hidden] { display: none; }
.post-tile a { display: flex; flex-direction: column; height: 100%; background: var(--card); border-radius: 18px; overflow: hidden; box-shadow: var(--shadow); transition: box-shadow .4s var(--ease), transform .4s var(--ease); }
.post-tile a:hover { box-shadow: var(--shadow-hover); transform: translateY(-3px); }
.post-tile--big { grid-column: 1 / -1; }
.post-tile--big a { flex-direction: row; }
.post-tile--big .tile-art { flex: 1.35; aspect-ratio: auto; min-height: 340px; }
.post-tile--big .post-tile__body { flex: 1; justify-content: center; padding: 40px; }
.post-tile--big .post-tile__title { font-size: clamp(28px, 3vw, 36px); }
.post-tile__body { display: flex; flex-direction: column; gap: 6px; padding: 22px 24px 26px; flex: 1; }
.post-tile .eyebrow { font-size: 12px; font-weight: 600; letter-spacing: .02em; text-transform: uppercase; color: var(--text-2); margin: 0; }
.post-tile__title { font-size: 21px; line-height: 1.2; font-weight: 600; letter-spacing: -.02em; text-wrap: balance; }
.post-tile time { margin-top: auto; padding-top: 10px; font-size: 14px; color: var(--text-2); }
.tile-art { aspect-ratio: 16 / 10; position: relative; display: grid; place-items: center; overflow: hidden; }
.tile-art--book { background: radial-gradient(circle at 50% 120%, color-mix(in srgb, var(--cover) 55%, #fff) 0%, color-mix(in srgb, var(--cover) 20%, #f5f5f7) 60%); }
:root[data-theme="dark"] .tile-art--book { background: radial-gradient(circle at 50% 120%, color-mix(in srgb, var(--cover) 70%, #000), #161617 65%); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .tile-art--book { background: radial-gradient(circle at 50% 120%, color-mix(in srgb, var(--cover) 70%, #000), #161617 65%); } }
.tile-art__book { width: 30%; max-width: 150px; aspect-ratio: 5 / 7; border-radius: 2px 6px 6px 2px; background: linear-gradient(90deg, rgba(0,0,0,.35) 0 4%, rgba(255,255,255,.14) 6%, transparent 11%), var(--cover); box-shadow: 10px 16px 30px rgba(0,0,0,.28); display: flex; align-items: flex-end; padding: 10% 10% 12% 14%; transform: rotate(-4deg); transition: transform .6s var(--ease); }
.post-tile a:hover .tile-art__book { transform: rotate(0) translateY(-6px); }
.tile-art__book span { font-size: clamp(9px, 1vw, 13px); line-height: 1.08; font-weight: 600; color: #f1e6cc; letter-spacing: -.01em; }
.tile-art--essay { background: radial-gradient(circle at 15% 20%, #cfe4ff, transparent 50%), radial-gradient(circle at 85% 30%, #f2d3ff, transparent 55%), radial-gradient(circle at 50% 100%, #ffd9c9, transparent 60%), #f5f5f7; }
:root[data-theme="dark"] .tile-art--essay { background: radial-gradient(circle at 15% 20%, #0b3a6e, transparent 50%), radial-gradient(circle at 85% 30%, #4b1d66, transparent 55%), radial-gradient(circle at 50% 100%, #5e2412, transparent 60%), #161617; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .tile-art--essay { background: radial-gradient(circle at 15% 20%, #0b3a6e, transparent 50%), radial-gradient(circle at 85% 30%, #4b1d66, transparent 55%), radial-gradient(circle at 50% 100%, #5e2412, transparent 60%), #161617; } }
.tile-art--essay span { font-size: clamp(96px, 11vw, 150px); font-weight: 300; line-height: 1; color: var(--text); opacity: .82; transition: transform .6s var(--ease); }
.post-tile a:hover .tile-art--essay span { transform: translateY(-6px); }
.post-tile--big time { margin-top: 14px; }
.empty { font-size: 19px; color: var(--text-2); padding: 40px 0; text-align: center; }

/* ------------------------------------------------------------- article */
.article { max-width: 740px; margin: 0 auto; padding: 0 var(--gutter); }
.article__head { padding: clamp(48px, 7vw, 80px) 0 8px; }
.article__head .eyebrow { font-size: 12px; font-weight: 600; letter-spacing: .04em; text-transform: uppercase; color: var(--text-2); margin-bottom: 6px; }
.article__date { margin: 0 0 14px; font-size: 14px; color: var(--text-2); }
.article__title { margin: 0; font-size: clamp(36px, 5.2vw, 52px); line-height: 1.08; font-weight: 700; letter-spacing: -.028em; text-wrap: balance; }
.article__dek { margin: 18px 0 0; font-size: clamp(19px, 2vw, 22px); line-height: 1.4; color: var(--text-2); font-weight: 400; letter-spacing: .005em; }
.bookcard { display: flex; gap: 20px; align-items: center; margin-top: 32px; padding: 18px 22px; background: var(--bg-2); border-radius: 18px; }
.bookcard__mini { flex: none; width: 50px; height: 70px; border-radius: 2px 5px 5px 2px; background: linear-gradient(90deg, rgba(0,0,0,.35) 0 6%, rgba(255,255,255,.14) 9%, transparent 16%), var(--cover); box-shadow: 4px 6px 14px rgba(0,0,0,.2); }
.bookcard dl { margin: 0; display: flex; flex-wrap: wrap; gap: 10px 34px; }
.bookcard dt { font-size: 12px; font-weight: 600; color: var(--text-2); }
.bookcard dd { margin: 0; font-size: 15px; }
.rating { color: #ff9f0a; letter-spacing: .05em; }
.rating span { color: var(--rule); }

.prose { padding: 32px 0 8px; font-size: 19px; line-height: 1.58; letter-spacing: -.012em; }
.prose > * { margin: 0 0 1.1em; }
.prose h2 { font-size: clamp(26px, 3vw, 32px); line-height: 1.15; font-weight: 600; letter-spacing: -.022em; margin: 1.8em 0 .5em; }
.prose h3 { font-size: 21px; font-weight: 600; margin: 1.6em 0 .4em; }
.prose a { color: var(--link); }
.prose a:hover { text-decoration: underline; }
.prose strong { font-weight: 600; }
.prose ul, .prose ol { padding-left: 1.3em; }
.prose li { margin: .4em 0; }
.prose blockquote { margin: 1.6em 0; padding: 4px 0 4px 22px; border-left: 3px solid var(--rule); font-size: 1.1em; color: var(--text-2); }
.prose code { font: .84em var(--mono); background: var(--bg-2); padding: .12em .4em; border-radius: 6px; }
.prose pre { font: 14px/1.6 var(--mono); background: var(--bg-2); padding: 20px 22px; border-radius: 14px; overflow-x: auto; }
.prose pre code { background: none; padding: 0; font-size: inherit; }
.prose hr { border: 0; height: 1px; background: var(--rule); margin: 2.4em 0; }
.prose img { border-radius: 14px; margin: 1.6em auto; }
.prose .math-block { overflow-x: auto; overflow-y: hidden; margin: 1.6em 0; padding: 22px 16px; background: var(--bg-2); border-radius: 18px; text-align: center; }
.prose .katex { font-size: 1.05em; }
.prose .math-block .katex { font-size: 1.28em; }
.article__foot { padding-bottom: 24px; }
.tags { display: flex; flex-wrap: wrap; gap: 8px; margin: 16px 0 0; }
.tags span { font-size: 13px; padding: 5px 12px; border-radius: 980px; background: var(--bg-2); color: var(--text-2); }
.more-reading { background: var(--bg-2); padding: 64px var(--gutter) 80px; margin-top: 56px; }
.more-reading > * { max-width: var(--max); margin-inline: auto; }
.more-reading__title { font-size: 28px; font-weight: 600; letter-spacing: -.02em; margin-bottom: 24px; }
.about .prose { padding-top: 8px; }

/* ------------------------------------------------------------- library */
.lineup { max-width: var(--max); margin: 0 auto; padding: 24px var(--gutter) 96px; display: grid; grid-template-columns: repeat(2, 1fr); gap: 48px 24px; }
.lineup__item { display: flex; flex-direction: column; align-items: center; text-align: center; }
.lineup__stage { height: 420px; display: grid; place-items: center; width: 100%; }
.lineup__status { margin: 18px 0 4px; font-size: 12px; font-weight: 600; letter-spacing: .02em; color: var(--eyebrow); }
.lineup__name { margin: 0; font-size: 28px; line-height: 1.14; font-weight: 600; letter-spacing: -.02em; max-width: 14em; text-wrap: balance; }
.lineup__tag { margin: 8px 0 22px; font-size: 15px; color: var(--text-2); }
.lineup__item--soon .lineup__status { color: var(--text-3); }
.ghost-book { width: clamp(200px, 22vw, 260px); aspect-ratio: 5 / 7; border: 2px dashed var(--rule); border-radius: 6px 12px 12px 6px; display: grid; place-items: center; color: var(--text-3); font-size: 17px; font-weight: 500; }
.ctas--center { justify-content: center; }
.features + .ctas { margin-top: 56px; }

/* ------------------------------------------------------------- footer */
.gfoot { background: var(--bg-2); color: var(--text-2); font-size: 12px; line-height: 1.33; letter-spacing: -.01em; }
body.is-grey .gfoot { border-top: 1px solid var(--rule); }
.gfoot__in { max-width: var(--max); margin: 0 auto; padding: 18px var(--gutter) 22px; }
.gfoot__notes { padding: 14px 0 18px; border-bottom: 1px solid var(--rule); }
.gfoot__notes p { margin: 0; }
.gfoot__cols { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; padding: 22px 0 26px; }
.gfoot__cols div { display: flex; flex-direction: column; gap: 8px; }
.gfoot__cols h3 { margin: 0 0 4px; font-size: 12px; font-weight: 600; color: var(--text); }
.gfoot__cols a { color: var(--text-2); }
.gfoot__cols a:hover { color: var(--text); text-decoration: underline; }
.gfoot__legal { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px; padding-top: 14px; border-top: 1px solid var(--rule); color: var(--text-3); }
.gfoot__legal p { margin: 0; }

/* ------------------------------------------------------------- 404 */
.nf__code { margin: 0 0 8px; font-size: clamp(80px, 14vw, 160px); font-weight: 700; line-height: 1; letter-spacing: -.05em; }
.nf .ctas { margin-top: 28px; }

/* ------------------------------------------------------------- motion */
.js .reveal { opacity: 0; transform: translateY(24px); transition: opacity 1s var(--ease), transform 1s var(--ease); transition-delay: var(--d, 0s); }
.js .reveal.is-in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .reveal { opacity: 1; transform: none; transition: none; }
  .book3d__body, .promo, .post-tile a, .tile-art__book, .logo { transition: none; }
}

/* ------------------------------------------------------------- responsive */
@media (max-width: 1068px) {
  .features { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 900px) {
  .playground { grid-template-columns: 1fr; }
  .playground__controls { display: grid; grid-template-columns: 1fr 1fr; gap: 20px 28px; }
  .playground__controls .seg, .playground__controls .readout { grid-column: 1 / -1; }
  .readout { grid-template-columns: repeat(3, 1fr); gap: 16px; }
  .readout > div { flex-direction: column; gap: 4px; }
  .promo-grid { grid-template-columns: 1fr; }
  .tiles { grid-template-columns: repeat(2, 1fr); }
  .post-tile--big a { flex-direction: column; }
  .post-tile--big .tile-art { min-height: 0; aspect-ratio: 16 / 9; }
  .post-tile--big .post-tile__body { padding: 24px 26px 28px; }
}
@media (max-width: 734px) {
  body { font-size: 17px; }
  .gnav__in { gap: 14px; }
  .gnav__links { gap: 16px; }
  .gnav__brand { font-size: 13px; gap: 7px; }
  .gnav__links a { font-size: 12px; }
  .lnav__title { font-size: 19px; }
  .lnav__links a:not(.btn) { display: none; }
  .hero { padding-top: 44px; }
  .hero__stage { padding: 48px 0 64px; }
  .stats { grid-template-columns: repeat(2, 1fr); row-gap: 36px; margin: 48px 0 40px; }
  .features { grid-template-columns: 1fr; gap: 12px; }
  .feature-card { display: flex; gap: 18px; align-items: center; padding: 20px; }
  .feature-card__icon { margin: 0; flex: none; width: 34px; height: 34px; }
  .feature-card p { font-size: 17px; }
  .playground { margin-top: 40px; border-radius: 22px; }
  .playground__chart { padding: 18px 8px 8px 10px; }
  .playground__controls { grid-template-columns: 1fr; padding: 22px 20px; }
  .playground__cap { padding: 14px 20px 18px; }
  .readout dt small { display: block; font-size: 12px; }
  .readout dd { font-size: 21px; }
  .pg-axis text { font-size: 19px; }
  .pg-cursor text { font-size: 20px; }
  .promo { min-height: 480px; padding: 44px 24px; }
  .tiles, .tiles--two { grid-template-columns: 1fr; }
  .lineup { grid-template-columns: 1fr; padding-bottom: 64px; }
  .lineup__stage { height: 360px; }
  .prose { font-size: 18px; }
  .bookcard { align-items: flex-start; }
  .gfoot__cols { grid-template-columns: 1fr 1fr; }
}
/* Phones: the full site name stays on one line; theme follows the system setting */
@media (max-width: 430px) {
  .gnav__in { padding: 0 16px; gap: 10px; }
  .gnav__links { gap: 12px; }
  .gnav__theme { display: none; }
}
@media (max-width: 360px) {
  .gnav__in { padding: 0 12px; gap: 8px; }
  .gnav__links { gap: 10px; }
  .gnav__brand { font-size: 12px; gap: 6px; }
  .gnav__links a { font-size: 11px; }
  .gnav__links a[href="/about/"] { display: none; }
}