/* ============================================================
   AutoOptm — design system
   Anthropic-adjacent: warm paper, high-contrast ink, one signal
   colour, generous type scale, restraint everywhere except the
   two or three places where motion actually explains something.
   No webfonts: Google Fonts is unreliable behind the GFW and
   Vercel/Cloudflare both recommend self-hosting for CN traffic.
   Swap in self-hosted woff2 later via --font / --mono only.
   ============================================================ */

:root {
  --paper:   #FCFCFB;
  --paper-2: #F6F5F1;
  --card:    #FFFFFF;
  --ink:     #16161A;
  --ink-2:   #4A4D52;
  --ink-3:   #90939A;
  --hair:    #E7E6E2;
  --hair-2:  #F1F0EC;
  --signal:  #1A3FE0;
  --signal-soft: rgba(26, 63, 224, .08);
  --clay:    #C1603F;
  --good:    #1F7A4D;

  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
          "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
          "Liberation Mono", monospace;

  --w: 1140px;
  --ease: cubic-bezier(.22, .61, .36, 1);
  --ease-out: cubic-bezier(.16, 1, .3, 1);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper:   #0E0E10;
    --paper-2: #141416;
    --card:    #1A1A1D;
    --ink:     #F2F1EE;
    --ink-2:   #A8ABB2;
    --ink-3:   #6B6E75;
    --hair:    #2A2A2E;
    --hair-2:  #202024;
    --signal:  #6E8BFF;
    --signal-soft: rgba(110, 139, 255, .12);
    --clay:    #E0866198;
  }
}
:root[data-theme="dark"] {
  --paper: #0E0E10; --paper-2: #141416; --card: #1A1A1D;
  --ink: #F2F1EE; --ink-2: #A8ABB2; --ink-3: #6B6E75;
  --hair: #2A2A2E; --hair-2: #202024;
  --signal: #6E8BFF; --signal-soft: rgba(110, 139, 255, .12);
}

* { 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(--paper);
  color: var(--ink);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.65;
  font-weight: 400;
  letter-spacing: -.003em;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "tnum";
}

.wrap { max-width: var(--w); margin: 0 auto; padding: 0 28px; }
.narrow { max-width: 760px; }

/* ---------- type ---------- */
h1, h2, h3 { margin: 0; letter-spacing: -.035em; font-weight: 500; line-height: 1.08; }
h1 { font-size: clamp(40px, 6.6vw, 76px); }
h2 { font-size: clamp(28px, 3.8vw, 42px); line-height: 1.14; }
h3 { font-size: 18px; letter-spacing: -.015em; line-height: 1.4; }
p  { margin: 0 0 16px; color: var(--ink-2); }
p:last-child { margin-bottom: 0; }
strong { font-weight: 550; color: var(--ink); }
a { color: inherit; text-decoration: none; }
.lead { font-size: clamp(17px, 2vw, 20px); line-height: 1.6; color: var(--ink-2); max-width: 34em; }

.eyebrow {
  font-family: var(--mono); font-size: 11px; font-weight: 500;
  letter-spacing: .18em; text-transform: uppercase; color: var(--ink-3);
  display: flex; align-items: baseline; gap: 10px; margin: 0 0 18px;
}
.eyebrow i { font-style: normal; color: var(--signal); }

/* ---------- nav ---------- */
header.nav {
  position: sticky; top: 0; z-index: 60;
  border-bottom: 1px solid transparent;
  transition: border-color .3s, background .3s, backdrop-filter .3s;
}
header.nav.stuck {
  background: color-mix(in srgb, var(--paper) 82%, transparent);
  backdrop-filter: saturate(1.6) blur(14px);
  -webkit-backdrop-filter: saturate(1.6) blur(14px);
  border-bottom-color: var(--hair);
}
.nav-in { display: flex; align-items: center; gap: 28px; height: 62px; }
.logo { font-weight: 600; letter-spacing: -.04em; font-size: 18px; display: flex; align-items: center; gap: 9px; }
.logo .mark {
  width: 17px; height: 17px; position: relative; flex: 0 0 auto;
}
.logo .mark::before, .logo .mark::after {
  content: ""; position: absolute; width: 11px; height: 11px; border-radius: 3px;
}
.logo .mark::before { left: 0; top: 0; background: var(--ink); }
.logo .mark::after  { right: 0; bottom: 0; background: var(--signal); mix-blend-mode: multiply; }
@media (prefers-color-scheme: dark) { .logo .mark::after { mix-blend-mode: screen; } }
.nav-links { display: flex; gap: 24px; margin-left: 8px; }
.nav-links a { font-size: 14.5px; color: var(--ink-2); transition: color .18s; }
.nav-links a:hover { color: var(--ink); }
.nav-right { margin-left: auto; display: flex; align-items: center; gap: 12px; }

.ghost {
  font-family: var(--mono); font-size: 11.5px; letter-spacing: .06em;
  border: 1px solid var(--hair); border-radius: 7px; padding: 5px 9px;
  color: var(--ink-3); background: transparent; cursor: pointer;
  transition: border-color .18s, color .18s;
}
.ghost:hover { border-color: var(--ink-3); color: var(--ink); }

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--ink); color: var(--paper);
  font-size: 14.5px; font-weight: 500; letter-spacing: -.01em;
  padding: 9px 18px; border-radius: 9px; border: 1px solid var(--ink);
  cursor: pointer; white-space: nowrap;
  transition: transform .22s var(--ease-out), box-shadow .22s, opacity .18s;
}
.btn:hover { transform: translateY(-1px); box-shadow: 0 6px 20px -6px rgba(0,0,0,.28); }
.btn:active { transform: translateY(0); }
.btn.primary { background: var(--signal); border-color: var(--signal); color: #fff; }
.btn.quiet { background: transparent; color: var(--ink); border-color: var(--hair); }
.btn.quiet:hover { border-color: var(--ink-3); box-shadow: none; }
.btn.lg { font-size: 16px; padding: 13px 24px; border-radius: 11px; }
.btn .arr { transition: transform .25s var(--ease-out); }
.btn:hover .arr { transform: translateX(3px); }

/* ---------- hero ---------- */
.hero { position: relative; padding: 84px 0 24px; overflow: hidden; }
.hero::before {
  /* pointer-tracked spotlight; set --mx/--my from JS */
  content: ""; position: absolute; inset: -40% -10% auto -10%; height: 900px;
  background: radial-gradient(520px 380px at var(--mx, 50%) var(--my, 30%),
              var(--signal-soft), transparent 68%);
  pointer-events: none; opacity: 0; transition: opacity .8s;
}
.hero.lit::before { opacity: 1; }
.hero-grid { display: grid; grid-template-columns: 1fr; gap: 44px; position: relative; }
@media (min-width: 1000px) {
  .hero-grid { grid-template-columns: minmax(0,1.05fr) minmax(0,.95fr); gap: 56px; align-items: center; }
}
h1 .rot { color: var(--signal); }
.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 30px; }
.hero-note { font-family: var(--mono); font-size: 12px; color: var(--ink-3); margin-top: 18px; letter-spacing: .01em; }

/* ---------- speedup visual ---------- */
.gauge {
  border: 1px solid var(--hair); border-radius: 14px; background: var(--card);
  padding: 22px 24px 20px; box-shadow: 0 1px 2px rgba(0,0,0,.03);
}
.gauge-head { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 20px; }
.gauge-head .t { font-family: var(--mono); font-size: 11px; letter-spacing: .12em; text-transform: uppercase; color: var(--ink-3); }
.gauge-head .r { font-size: 38px; font-weight: 500; letter-spacing: -.04em; color: var(--signal); font-variant-numeric: tabular-nums; }
.track { margin-bottom: 14px; }
.track .lbl { display: flex; justify-content: space-between; font-family: var(--mono); font-size: 11.5px; color: var(--ink-3); margin-bottom: 6px; }
.track .lbl b { font-weight: 400; color: var(--ink-2); }
.bar { height: 8px; border-radius: 5px; background: var(--hair-2); overflow: hidden; }
.bar > span { display: block; height: 100%; border-radius: 5px; width: 0; transition: width 1.1s var(--ease-out); }
.bar.base > span { background: var(--ink-3); }
.bar.opt  > span { background: var(--signal); }

.findings { border-top: 1px solid var(--hair); margin-top: 18px; padding-top: 14px; }
.find {
  display: grid; grid-template-columns: 1fr auto auto; gap: 0 14px; align-items: baseline;
  font-family: var(--mono); font-size: 12px; line-height: 2.1; color: var(--ink-2);
  opacity: 0; transform: translateY(4px);
}
.find.in { opacity: 1; transform: none; transition: opacity .45s, transform .45s var(--ease-out); }
.find em { font-style: normal; color: var(--signal); }
.find s { text-decoration: none; color: var(--ink-3); }
.find.rolled em { color: var(--ink-3); }
.quote {
  display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap;
  border-top: 1px solid var(--hair); margin-top: 12px; padding-top: 13px;
  font-family: var(--mono); font-size: 12px; color: var(--ink-2);
}
.quote em { font-style: normal; color: var(--signal); }
.pill {
  background: var(--signal); color: #fff; font-size: 11.5px; letter-spacing: .03em;
  padding: 6px 13px; border-radius: 20px; font-family: var(--font);
}

/* ---------- proof strip ---------- */
.strip { border-top: 1px solid var(--hair); border-bottom: 1px solid var(--hair); margin-top: 64px; }
.strip-in { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0; }
@media (min-width: 760px) { .strip-in { grid-template-columns: repeat(4, 1fr); } }
.stat { padding: 26px 0 24px; border-right: 1px solid var(--hair); }
.stat:last-child { border-right: 0; }
@media (max-width: 759px) { .stat:nth-child(2n) { border-right: 0; } .stat:nth-child(-n+2) { border-bottom: 1px solid var(--hair); } }
.stat .n { font-size: 30px; font-weight: 500; letter-spacing: -.04em; font-variant-numeric: tabular-nums; }
.stat .c { font-size: 13px; color: var(--ink-3); margin-top: 2px; }

/* ---------- sections ---------- */
section { padding: 96px 0; }
section.tint { background: var(--paper-2); }
.sec-head { max-width: 640px; margin-bottom: 48px; }
.sec-head p { margin-top: 18px; font-size: 17px; }

.cols { display: grid; gap: 28px; grid-template-columns: 1fr; }
@media (min-width: 800px) { .cols.c2 { grid-template-columns: 1fr 1fr; } .cols.c4 { grid-template-columns: repeat(4, 1fr); gap: 20px; } }
@media (min-width: 560px) and (max-width: 799px) { .cols.c4 { grid-template-columns: 1fr 1fr; } }

.step { border-top: 1px solid var(--hair); padding-top: 18px; }
.step .k { font-family: var(--mono); font-size: 11px; letter-spacing: .14em; color: var(--signal); margin-bottom: 10px; }
.step h3 { margin-bottom: 8px; }
.step p { font-size: 14.5px; margin: 0; }

figure { margin: 0; }
figure svg { display: block; width: 100%; height: auto; }
.sv-l { font-size: 12px; fill: var(--ink); font-weight: 500; }
.sv-s { font-size: 11px; fill: var(--ink-3); }
.sv-a { font-size: 12px; fill: var(--signal); font-weight: 500; }
.sv-box { fill: none; stroke: var(--hair); stroke-width: 1.25; }
.sv-acc { fill: none; stroke: var(--signal); stroke-width: 1.25; }
.sv-line { stroke: var(--hair); stroke-width: 1.25; fill: none; }
.sv-draw { stroke-dasharray: var(--len); stroke-dashoffset: var(--len); }
.in .sv-draw { stroke-dashoffset: 0; transition: stroke-dashoffset 1s var(--ease-out) var(--d, 0s); }

table { width: 100%; border-collapse: collapse; font-size: 15px; }
th, td { text-align: left; padding: 15px 16px 15px 0; border-bottom: 1px solid var(--hair); vertical-align: top; line-height: 1.55; }
th { font-family: var(--mono); font-size: 10.5px; letter-spacing: .14em; text-transform: uppercase; color: var(--ink-3); font-weight: 500; }
td { color: var(--ink-2); }
td:first-child { color: var(--ink); font-weight: 500; }
td.us { color: var(--ink); }

.note { border-left: 2px solid var(--signal); padding-left: 20px; margin-top: 32px; }
.note p { color: var(--ink); font-size: 16.5px; }

/* ---------- pricing ---------- */
.plans { display: grid; gap: 20px; grid-template-columns: 1fr; align-items: start; }
@media (min-width: 900px) { .plans { grid-template-columns: repeat(4, 1fr); } }
@media (min-width: 600px) and (max-width: 899px) { .plans { grid-template-columns: 1fr 1fr; } }
.plan {
  border: 1px solid var(--hair); border-radius: 14px; background: var(--card);
  padding: 24px 22px 22px; display: flex; flex-direction: column; min-height: 100%;
  transition: transform .28s var(--ease-out), box-shadow .28s, border-color .28s;
}
.plan:hover { transform: translateY(-3px); box-shadow: 0 14px 34px -18px rgba(0,0,0,.3); }
.plan.feature { border-color: var(--signal); box-shadow: 0 0 0 1px var(--signal); }
.plan .name { font-family: var(--mono); font-size: 11px; letter-spacing: .14em; text-transform: uppercase; color: var(--ink-3); }
.plan .price { font-size: 34px; font-weight: 500; letter-spacing: -.04em; margin: 14px 0 2px; font-variant-numeric: tabular-nums; }
.plan .price small { font-size: 14px; font-weight: 400; color: var(--ink-3); letter-spacing: 0; }
.plan .cr { font-family: var(--mono); font-size: 12.5px; color: var(--signal); margin-bottom: 16px; }
.plan ul { list-style: none; margin: 0 0 20px; padding: 0; }
.plan li { font-size: 14px; color: var(--ink-2); padding: 6px 0 6px 20px; position: relative; line-height: 1.5; }
.plan li::before { content: ""; position: absolute; left: 2px; top: 13px; width: 7px; height: 7px; border-radius: 2px; background: var(--hair); }
.plan li.on::before { background: var(--signal); }
.plan .cta { margin-top: auto; }
.plan .btn { width: 100%; justify-content: center; }
.badge2x {
  display: inline-flex; align-items: center; gap: 6px; font-family: var(--mono);
  font-size: 10.5px; letter-spacing: .1em; text-transform: uppercase;
  color: var(--signal); background: var(--signal-soft);
  padding: 3px 9px; border-radius: 20px; margin-left: 8px;
}
.badge2x::before { content: ""; width: 5px; height: 5px; border-radius: 50%; background: var(--signal); animation: blip 2.4s var(--ease) infinite; }
@keyframes blip { 0%, 100% { opacity: 1; transform: scale(1); } 50% { opacity: .35; transform: scale(.7); } }
@media (prefers-reduced-motion: reduce) { .badge2x::before { animation: none; } }

.rates { font-family: var(--mono); font-size: 13.5px; }
.rates td:first-child { color: var(--ink); }
.rates td:last-child { text-align: right; color: var(--signal); white-space: nowrap; }

/* ---------- cta ---------- */
.endcta { text-align: center; padding: 110px 0; }
.endcta h2 { max-width: 15em; margin: 0 auto 22px; }
.endcta .hero-cta { justify-content: center; }

footer { border-top: 1px solid var(--hair); padding: 40px 0 56px; }
.foot { display: flex; flex-wrap: wrap; gap: 20px 32px; align-items: center; font-size: 13px; color: var(--ink-3); }
.foot a { color: var(--ink-3); } .foot a:hover { color: var(--ink); }
.foot .sp { margin-left: auto; }

/* ---------- reveal ----------
   Scoped to html.js on purpose. Content must be READABLE BY DEFAULT and the
   animation layered on top; the inverse (CSS hides, JS reveals) means any
   failure of the reveal path — no JS, a script error, a tab that is never
   painted so IntersectionObserver never delivers — leaves the entire page
   blank. The .js class is set by an inline script in <head>, before first
   paint, so there is no flash of visible-then-hidden content. */
.js .rv { opacity: 0; transform: translateY(14px); }
.js .rv.in { opacity: 1; transform: none; transition: opacity .7s var(--ease-out) var(--d, 0s), transform .7s var(--ease-out) var(--d, 0s); }
@media (prefers-reduced-motion: reduce) {
  .js .rv, .js .rv.in { opacity: 1; transform: none; transition: none; }
  .bar > span { transition: none; }
  .find { opacity: 1; transform: none; }
  .in .sv-draw { transition: none; stroke-dashoffset: 0; }
}

/* i18n: every string ships both languages; JS flips the html[lang] attr */
html[lang="en"] .zh, html[lang="zh"] .en { display: none; }

@media (max-width: 720px) {
  .wrap { padding: 0 20px; }
  section { padding: 68px 0; }
  .nav-links { display: none; }
  .hero { padding-top: 52px; }
}