/* tennowtech.com — hand-authored. Colours and fonts come only from tokens.css.
   Layout modelled on brilliant.org/about: centred hero, then rows of
   "heading left / prose right", a collapsible method list and a dark close. */

*, *::before, *::after { box-sizing: border-box; }
/* Section tints are brand tokens mixed into paper, so no new colours exist.
   Like brilliant.org/about, colour carries the ideals and steps back for the
   reasoning: hero → approach is vivid (tint-* gradients; .rev flips the
   direction so neighbours read as separate), learners is .calm and method
   returns to colour in green, the app's "correct" — the loop that gets you there. */
:root {
  --hdr: 69px;   /* measured height of .hdr */
  --tint-gold:  color-mix(in oklab, var(--progress) 14%, var(--paper));
  --tint-red:   color-mix(in oklab, var(--accent) 7%, var(--paper));
  --tint-green: color-mix(in oklab, var(--correct) 9%, var(--paper));
  --tint-ink:   color-mix(in oklab, var(--ink) 6%, var(--paper));
  /* Motion: iOS's sheet curve for anything that moves, a slight overshoot for
     things you touch. */
  --ease: cubic-bezier(.32, .72, 0, 1);
  --ease-pop: cubic-bezier(.34, 1.4, .64, 1);
}
html { scroll-behavior: smooth; scroll-padding-top: var(--hdr); }
/* No overflow-x: hidden on body — it breaks the sticky header. */
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink-body);
  font-family: var(--text);
  font-size: 17px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
img, svg { display: block; max-width: 100%; }
a { color: var(--link); }
a:hover { color: var(--link-hover); }
h1, h2, h3 { color: var(--ink); font-family: var(--display); margin: 0; line-height: 1.25; letter-spacing: -0.01em; }

.wrap { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 24px; }

.skip { position: absolute; left: -999px; top: 8px; background: var(--ink); color: var(--on-ink); padding: 8px 12px; z-index: 20; }
.skip:focus { left: 8px; }

/* ── header ─────────────────────────────────────────── */
.hdr {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 14px 24px;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
  transition: background-color .3s, border-color .3s;
}
/* Like an iOS nav bar: no hairline at the top, frosted once content scrolls
   under it. site.js sets .hdr--top; without JS the hairline simply stays. */
.hdr--top { border-bottom-color: transparent; }
@supports (backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px)) {
  .hdr:not(.hdr--top) {
    background: color-mix(in oklab, var(--paper) 78%, transparent);
    -webkit-backdrop-filter: saturate(1.8) blur(18px);
    backdrop-filter: saturate(1.8) blur(18px);
  }
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); }
.brand__mark { border-radius: 7px; }
.brand__name { font-family: var(--wordmark); font-weight: 600; font-size: 20px; white-space: nowrap; }
.nav { display: flex; align-items: center; gap: 24px; font-size: 15px; }
/* Keep :not(.btn) — plain `.nav a` out-specifies .btn. */
.nav a:not(.btn) { position: relative; text-decoration: none; color: var(--ink-2); transition: color .2s; }
.nav a:not(.btn):hover { color: var(--ink); }
/* Underline grows in from the left, leaves to the right. */
.nav a:not(.btn)::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -3px; height: 1.5px;
  background: currentColor; border-radius: 1px;
  transform: scaleX(0); transform-origin: right; transition: transform .35s var(--ease);
}
.nav a:not(.btn):hover::after { transform: scaleX(1); transform-origin: left; }
.nav__sep { width: 1px; height: 18px; background: var(--line); }
.lang { color: var(--ink-muted); font-size: 14px; white-space: nowrap; }
.lang .on { color: var(--ink); font-weight: 600; }

.btn {
  display: inline-block;
  padding: 10px 18px;
  border-radius: 999px;
  background: var(--accent-fill);
  color: var(--on-accent-fill);
  font-weight: 600;
  text-decoration: none;
  line-height: 1.3;
  transition: transform .45s var(--ease-pop), filter .2s, box-shadow .3s var(--ease);
}
.btn:hover { color: var(--on-accent-fill); filter: brightness(1.08); }
/* Press: a quick squeeze, released with a little spring. */
.btn:active { transform: scale(.95); transition-duration: .1s; }
.btn--light { background: var(--on-ink); color: var(--ink); }
.btn--light:hover { color: var(--ink); transform: translateY(-2px); box-shadow: 0 14px 30px -12px color-mix(in oklab, var(--accent) 70%, transparent); }
.btn--light:active { transform: scale(.95); }

/* ── hero ───────────────────────────────────────────── */
.hero {
  /* Short of a full screen so the belt below peeks in. */
  min-height: calc(86svh - var(--hdr));
  display: flex; flex-direction: column; justify-content: center;
  text-align: center; padding: 72px 0 56px;
  background:
    radial-gradient(70% 90% at 0% 10%, color-mix(in oklab, var(--progress) 24%, var(--paper)), transparent 70%),
    radial-gradient(60% 80% at 100% 20%, color-mix(in oklab, var(--accent) 12%, var(--paper)), transparent 70%),
    radial-gradient(60% 70% at 80% 100%, color-mix(in oklab, var(--correct) 15%, var(--paper)), transparent 70%),
    var(--paper);
}
.hero h1 { font-size: clamp(36px, 6vw, 68px); line-height: 1.15; font-weight: 700; }
/* English lines are ~18.6em wide; size to the column so it stays two lines. */
.hero h1:lang(en) { font-size: clamp(28px, 5vw, 56px); }
.hero__eyebrow, .hero h1 { animation: rise .9s var(--ease) both; }
.hero h1 { animation-delay: .12s; }
@keyframes rise { from { opacity: 0; translate: 0 16px; } }
.hero__eyebrow { margin: 0 0 20px; font-size: 15px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-muted); }


/* ── heading-left / prose-right rows ────────────────── */
/* One section per screen: each fills the viewport below the sticky header. */
.row {
  min-height: calc(100svh - var(--hdr));
  display: flex; align-items: center;
  padding: 120px 0;
}
/* Top-anchored where content changes height (the method accordion): centred,
   the whole block would drift upward as a step opens. */
.row--top { align-items: flex-start; padding-top: clamp(120px, 20svh, 200px); }
.tint-gold  { --tint: var(--tint-gold); }
.tint-red   { --tint: var(--tint-red); }
.tint-green { --tint: var(--tint-green); }
.tint-ink   { --tint: var(--tint-ink); }
[class*="tint-"] { background: linear-gradient(90deg, var(--paper), var(--tint)); }
[class*="tint-"].rev { background: linear-gradient(90deg, var(--tint), var(--paper)); }
/* The reasoning half: flat paper, alternating with paper-tint, hairline between. */
.calm { background: var(--paper); border-top: 1px solid var(--line); }

.row__grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 2fr); gap: 64px; }
.row__grid > * { max-width: 100%; }
.row h2 { font-size: clamp(30px, 3.4vw, 44px); line-height: 1.25; }
.prose p { margin: 0 0 1.1em; }
.prose p:last-child { margin-bottom: 0; }
.lead { font-size: clamp(21px, 2.1vw, 26px); line-height: 1.5; color: var(--ink); font-weight: 500; }

/* Index cards: ruled lines and a red margin like a vocabulary card, set
   slightly askew and squared up on hover. Line pitch = line-height (28px). */
.tenets { list-style: none; margin: 44px 0 0; padding: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
.tenets li {
  position: relative; padding: 18px 20px 20px 34px; font-size: 15px; line-height: 28px;
  background:
    repeating-linear-gradient(transparent 0 27px, var(--line) 27px 28px) 0 18px / 100% calc(100% - 18px) no-repeat,
    var(--surface-raised);
  box-shadow: 0 1px 0 var(--line), 0 12px 20px -16px color-mix(in oklab, var(--ink) 50%, transparent);
  transform: rotate(-.8deg); transition: transform .25s ease;
}
/* The red margin is a real box, not a background stop: a hard-edged 1.5px
   gradient aliases into broken segments once the card is rotated. */
.tenets li::before {
  content: ""; position: absolute; top: 0; bottom: 0; left: 22px;
  border-left: 1.5px solid color-mix(in oklab, var(--accent) 45%, transparent);
}
.tenets li:nth-child(2n) { transform: rotate(.7deg); }
.tenets li:hover { transform: none; }
.tenets strong { display: block; color: var(--ink); font-size: 17px; }


/* ── statement belt (brilliant.org/about's "We help people excel…" strip) ──
   Marks are the app's hand: 圈 is the grading circle from BrushMarks.swift in
   `correct`; the highlighter is `progress` gold; the underline is the seal red. */
.belt {
  padding: 72px 0;
  text-align: center;
  background: linear-gradient(90deg,
    color-mix(in oklab, var(--accent) 4%, var(--paper)),
    color-mix(in oklab, var(--progress) 8%, var(--paper)));
}
.belt__text {
  max-width: 920px; margin: 0 auto;
  font-family: var(--display); font-weight: 600; color: var(--ink);
  font-size: clamp(26px, 3.6vw, 46px); line-height: 1.6; letter-spacing: -0.01em;
  text-wrap: balance;
}
.mk { position: relative; white-space: nowrap; isolation: isolate; }
/* Marks never wrap: an absolutely positioned SVG on a split inline box lands in
   the wrong place. The longest phrase still fits at 320px. The circle overhangs
   its word, so it gets room or it cuts into the next 字 (CJK has no spaces). */
.mk--circle { margin-inline: .2em; }
.mk__svg { position: absolute; max-width: none; overflow: visible; pointer-events: none; }
.mk__svg path { vector-effect: non-scaling-stroke; }
.mk--circle .mk__svg { left: -0.32em; right: -0.32em; top: -0.12em; bottom: -0.06em; width: calc(100% + 0.64em); height: calc(100% + 0.18em); }
.mk--circle path { fill: none; stroke: var(--correct); stroke-width: 3.5; stroke-linecap: round; }
.mk--hl .mk__svg { left: -3%; width: 106%; top: 48%; height: 46%; z-index: -1; }
.mk--hl path { fill: var(--progress); opacity: .45; }
.mk--ul .mk__svg { left: 0; width: 100%; bottom: -0.12em; height: 0.32em; }
.mk--ul path { fill: none; stroke: var(--accent); stroke-width: 4; stroke-linecap: round; }
/* Body-text circle: roomier and finer than the belt's, or it strikes the glyphs. */
.prose .mk--circle { margin-inline: .5em; }
.prose .mk--circle .mk__svg { left: -0.6em; right: auto; top: -0.3em; bottom: auto; width: calc(100% + 1.2em); height: calc(100% + 0.55em); }
.prose .mk--circle path { stroke-width: 2.2; }
.mk--ul2 .mk__svg { left: -2%; width: 104%; bottom: -0.34em; height: 0.42em; }
.mk--ul2 path { fill: none; stroke: var(--accent); stroke-width: 2; stroke-linecap: round; }

/* Drawn in, left to right like a pen, once the belt scrolls into view; static
   (fully drawn) without JS. A clip wipe, not stroke-dashoffset: dashes go wrong
   with vector-effect: non-scaling-stroke. */
.belt--pending .mk__svg { clip-path: inset(0 100% 0 0); }
.belt--drawn .mk__svg { animation: mk-wipe .6s cubic-bezier(.4, 0, .2, 1) both; }
.belt--drawn .mk--hl .mk__svg { animation-delay: .1s; }
.belt--drawn .mk--circle .mk__svg { animation-delay: .6s; }
.belt--drawn .mk--ul .mk__svg { animation-delay: 1.1s; }
@keyframes mk-wipe { from { clip-path: inset(0 100% 0 0); } to { clip-path: inset(0 0 0 0); } }

/* ── method: heading left, collapsible list right ─────── */
.row__note { margin: 20px 0 0; color: var(--ink-muted); font-size: 16px; line-height: 1.7; }
.acc { background: var(--surface-raised); border: 1px solid var(--line); border-radius: 16px; padding: 4px 24px; overflow: hidden; }
.acc__item + .acc__item { border-top: 1px solid var(--line); }
.acc__h { margin: 0; font: inherit; }
.acc__btn {
  display: flex; align-items: center; gap: 14px; width: 100%;
  padding: 20px 0; border: 0; background: transparent;
  font: inherit; font-weight: 600; color: var(--ink); font-size: 17px; text-align: left;
  cursor: pointer; -webkit-tap-highlight-color: transparent;
}
.acc__btn:focus-visible { outline: 2px solid var(--ink); outline-offset: 4px; border-radius: 4px; }
.acc__btn::after {
  content: ""; margin-left: auto; flex: none;
  width: 9px; height: 9px;
  border-right: 2px solid var(--ink-2); border-bottom: 2px solid var(--ink-2);
  transform: translateY(-3px) rotate(45deg); transition: transform .5s var(--ease);
}
.acc__btn[aria-expanded="true"]::after { transform: translateY(2px) rotate(-135deg); }
/* Ma Shan Zheng: numerals only. */
.acc__n { font-family: var(--brush); font-size: 26px; font-weight: 400; line-height: 1; color: var(--accent); width: 1.1em; text-align: center; }

/* Panels are open by default, so the steps read fine without JS. With JS
   (html.js, set inline in <head> so there's no open-then-shut flash on load)
   they start collapsed. Height animates via grid rows 0fr → 1fr: the
   browser interpolates the real content height, so there is nothing to measure
   and nothing to race; reversing mid-way is just another transition. */
.acc__panel { display: grid; grid-template-rows: 1fr; }
.acc__inner { min-height: 0; overflow: hidden; }
.acc__inner p { margin: 0; padding: 0 0 22px calc(1.1em * 26 / 17 + 14px); color: var(--ink-body); font-size: 16px; }
.js .acc__panel { grid-template-rows: 0fr; transition: grid-template-rows .5s var(--ease); }
.js .acc__item.is-open .acc__panel { grid-template-rows: 1fr; }
.js .acc__inner p { opacity: 0; translate: 0 -4px; transition: opacity .2s, translate .5s var(--ease); }
.js .acc__item.is-open .acc__inner p { opacity: 1; translate: none; transition-duration: .4s, .5s; transition-delay: .08s, 0s; }

/* ── join (dark close, like Brilliant's careers block) ─ */
.join {
  min-height: calc(100svh - var(--hdr));
  display: flex; align-items: center;
  text-align: center; padding: 120px 0;
  color: var(--on-ink-muted);
  background:
    radial-gradient(60% 80% at 50% 120%, color-mix(in oklab, var(--accent) 35%, var(--ink)), transparent 70%),
    var(--ink);
}
.join .join__tag {
  display: inline-block; margin: 0 0 20px; padding: 4px 14px;
  border: 1px solid var(--line-dark); border-radius: 999px;
  font-size: 13px; letter-spacing: 0.08em; color: var(--accent-dark);
}
.join h2 { color: var(--on-ink); font-size: clamp(30px, 4.5vw, 46px); }
.join p { max-width: 760px; margin: 20px auto 36px; font-size: 18px; }

/* ── footer ─────────────────────────────────────────── */
/* Brand block left, link columns right, a quiet legal bar, and one oversized
   brushed 十 bleeding off the corner — the "ten" in Ten Now. Ma Shan Zheng
   stays numerals-only: 十 is one. */
.foot {
  position: relative; overflow: hidden; isolation: isolate;
  background: var(--ink); color: var(--on-ink-muted);
  padding: 80px 0 36px; border-top: 1px solid var(--line-dark); font-size: 14px;
}
.foot a { color: var(--on-link); text-decoration: none; transition: color .2s; }
.foot a:hover { color: var(--on-ink); }

.foot__top { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: 64px; }
.foot .brand { color: var(--on-ink); }
.foot .brand__mark { border-radius: 8px; }
.foot__tag {
  max-width: 22em; margin: 20px 0 0;
  font-family: var(--display); font-weight: 500; color: var(--on-link);
  font-size: 17px; line-height: 1.5;
  text-wrap: balance;
}
.foot__co { margin: 24px 0 0; color: var(--on-ink-faint); font-size: 13px; line-height: 1.8; font-variant-numeric: tabular-nums; }

.foot__grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; padding-top: 6px; }
.foot__h {
  margin: 0 0 16px; color: var(--on-ink-faint);
  font-family: var(--text); font-size: 12px; font-weight: 600;
  letter-spacing: 0.12em; text-transform: uppercase;
}
.foot ul { list-style: none; margin: 0; padding: 0; }
.foot li { margin-bottom: 10px; font-size: 15px; }
/* Leaving the site: a small arrow that nudges out on hover. */
.foot a.ext::after {
  content: "↗"; display: inline-block; margin-left: 4px;
  font-size: .8em; opacity: .5;
  transition: transform .35s var(--ease), opacity .2s;
}
.foot a.ext:hover::after { transform: translate(2px, -2px); opacity: 1; }

.foot__legal {
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 24px;
  margin-top: 72px; padding-top: 24px; border-top: 1px solid var(--line-dark);
  color: var(--on-ink-faint); font-size: 12px;
}
.foot__mark {
  position: absolute; z-index: -1; right: -0.08em; bottom: -0.28em;
  font-family: var(--brush); font-size: clamp(220px, 34vw, 460px); line-height: 1;
  color: color-mix(in oklab, var(--on-ink) 5%, var(--ink));
  pointer-events: none; user-select: none;
}

/* ── scroll reveal ──────────────────────────────────── */
/* site.js adds .rv-on and tags each piece .rv, then .in as it scrolls into
   view; --d staggers a section's pieces. `translate`, not `transform`, so the
   tilted index cards keep their rotation. Hover transitions get no delay. */
.rv-on .rv {
  opacity: 0; translate: 0 22px;
  transition: opacity .8s var(--ease), translate .9s var(--ease),
              transform .5s var(--ease-pop), box-shadow .4s var(--ease);
  transition-delay: var(--d, 0ms), var(--d, 0ms), 0ms, 0ms;
}
.rv-on .rv.in { opacity: 1; translate: none; }
/* Index cards keep their original quiet square-up on hover. */
.rv-on .tenets .rv {
  transition: opacity .8s var(--ease), translate .9s var(--ease), transform .25s ease;
  transition-delay: var(--d, 0ms), var(--d, 0ms), 0ms;
}

/* ── narrow ─────────────────────────────────────────── */
@media (max-width: 820px) {
  .row__grid, .tenets { grid-template-columns: minmax(0, 1fr); }
  .row__grid { gap: 20px; }
  /* `>` keeps the language link: it sits inside .lang and must survive. */
  .nav > a:not(.btn), .nav__sep { display: none; }
  .hero { padding-top: 72px; }
  .row, .join { min-height: 0; padding: 88px 0; }
  .foot__top { grid-template-columns: minmax(0, 1fr); gap: 48px; }
  .foot { padding-top: 64px; }
  .belt { padding: 48px 0; }
}
@media (max-width: 420px) {
  .hdr { padding: 12px 16px; }
  .wrap { padding: 0 16px; }
  .nav { gap: 12px; }
  .nav .btn { padding: 8px 12px; font-size: 14px; white-space: nowrap; }
  /* No room for "EN / 繁中": show only the way out to the other language. */
  .lang .on, .lang__sep { display: none; }
  .brand { gap: 8px; }
  .brand__name { font-size: 17px; }
  .foot__grid { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
}
/* Smallest phones: the mark alone carries the brand; the CTA and the way out
   to the other language matter more than the wordmark. */
@media (max-width: 370px) {
  .brand__name { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
}

/* ── reduced motion: everything lands in its final state at once ── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important; animation-delay: 0s !important;
    transition-duration: .01ms !important; transition-delay: 0s !important;
  }
  html { scroll-behavior: auto; }
}