@font-face { font-family: 'EB Garamond'; font-weight: 500; font-display: swap; src: url(/fonts/eb-garamond-latin-500-normal.woff2) format('woff2'); }
@font-face { font-family: 'Atkinson Hyperlegible'; font-weight: 400; font-display: swap; src: url(/fonts/atkinson-hyperlegible-latin-400-normal.woff2) format('woff2'); }
@font-face { font-family: 'Atkinson Hyperlegible'; font-weight: 700; font-display: swap; src: url(/fonts/atkinson-hyperlegible-latin-700-normal.woff2) format('woff2'); }

:root {
  --paper: #E9ECEF;
  --card: #FBFBFC;
  --scan: #DCE0E5;
  --line: #C4CAD1;
  --ink: #10213A;
  --muted: #586579;
  --verify: #1F5EFF;
  --verify-dark: #1648CC;
  --fooled: #E0362C;
  --caught: #0B8F55;
  --ui: 'Atkinson Hyperlegible', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', system-ui, sans-serif;
  --scanned: 'EB Garamond', Garamond, 'Times New Roman', serif;
  --scanned-zh: 'Songti SC', STSong, 'Noto Serif SC', 'Source Han Serif SC', 'SimSun', serif;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 17px/1.55 var(--ui);
}
:lang(zh-CN) body, html:lang(zh-CN) { line-height: 1.7; }
h1, h2, h3, p { margin: 0; }
button { font: inherit; color: inherit; }
a { color: var(--verify-dark); text-underline-offset: 3px; }
:focus-visible { outline: 3px solid var(--verify); outline-offset: 2px; }
[hidden] { display: none !important; }

/* top bar */
.top {
  max-width: 1160px; margin: 0 auto; padding: 18px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; }
.brand-mark { width: 28px; height: 28px; color: var(--ink); }
.brand-name { font-weight: 700; font-size: 1.05rem; }
.brand-zh { color: var(--muted); font-size: .95rem; }
.lang {
  min-width: 56px; padding: 7px 14px; cursor: pointer;
  background: var(--card); border: 1px solid var(--line); border-radius: 3px;
  font-weight: 700; font-size: .95rem;
}
.lang:hover { border-color: var(--ink); }

/* hero */
.hero {
  max-width: 1160px; margin: 0 auto; padding: 28px 24px 0;
  display: grid; grid-template-columns: minmax(0, 1fr) 340px; gap: 48px; align-items: start;
}
.hero h1 {
  font-size: clamp(2rem, 1.2rem + 2.6vw, 3.1rem); line-height: 1.12; font-weight: 700;
  letter-spacing: -.01em; max-width: 18ch;
}
html:lang(zh-CN) .hero h1 { letter-spacing: 0; line-height: 1.25; max-width: 14em; }
.lede { margin-top: 14px; font-size: 1.15rem; color: var(--muted); max-width: 46ch; }

/* the verification widget */
.widget {
  margin-top: 28px; padding: 12px;
  background: var(--card); border: 1px solid var(--line); border-radius: 4px;
  box-shadow: 0 1px 0 rgba(16, 33, 58, .05), 0 10px 24px -16px rgba(16, 33, 58, .35);
}
.words { position: relative; border: 1px solid var(--line); line-height: 0; }
.words-art { width: 100%; height: auto; display: block; }
.words-art.stacked { display: none; }
.w-en { font: 500 96px var(--scanned); fill: #15181e; }
.w-zh { font: 700 80px var(--scanned-zh); fill: #15181e; }
.w-strike { fill: none; stroke: #15181e; stroke-width: 4.5; stroke-linecap: round; }
.refresh {
  position: absolute; right: 8px; bottom: 8px; width: 34px; height: 34px; padding: 6px;
  background: rgba(251, 251, 252, .9); border: 1px solid var(--line); border-radius: 3px; cursor: pointer;
  color: var(--muted); line-height: 0;
}
.refresh:hover { color: var(--ink); border-color: var(--ink); }
.refresh svg { width: 100%; height: 100%; }

.check-row {
  margin-top: 12px; padding: 14px 10px 8px;
  display: grid; grid-template-columns: auto minmax(0, 1fr) minmax(0, 200px); gap: 16px; align-items: center;
}
.checkbox {
  position: relative; width: 36px; height: 36px; padding: 0; border: 0; background: none; cursor: pointer;
}
.checkbox .box {
  position: absolute; inset: 0; background: #fff; border: 2px solid var(--line); border-radius: 3px;
  transition: border-color .15s;
}
.checkbox:hover .box { border-color: #8E99A7; }
.checkbox .tick { position: absolute; inset: -2px; width: 40px; height: 40px; opacity: 0; }
.checkbox .tick path {
  fill: none; stroke: var(--caught); stroke-width: 3.4; stroke-linecap: round; stroke-linejoin: round;
  stroke-dasharray: 30; stroke-dashoffset: 30;
}
.checkbox[data-state="loading"] .box {
  border-radius: 50%; border: 4px solid #BFD0FF; border-top-color: var(--verify);
  animation: spin .8s linear infinite;
}
.checkbox[data-state="done"] { cursor: default; }
.checkbox[data-state="done"] .box { opacity: 0; }
.checkbox[data-state="done"] .tick { opacity: 1; }
.checkbox[data-state="done"] .tick path { animation: draw .35s ease-out forwards; }
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes draw { to { stroke-dashoffset: 0; } }
.check-label { font-size: 1.25rem; font-weight: 700; cursor: pointer; }
.checkbox[data-state="done"] + .check-label { cursor: default; font-size: 1.05rem; }
.fine {
  font-size: .8rem; line-height: 1.45; color: var(--muted);
  border-left: 1px solid var(--line); padding-left: 14px;
}

/* chat challenge */
.chat {
  margin-top: 14px; overflow: hidden;
  background: var(--card); border: 1px solid var(--line); border-radius: 4px;
  box-shadow: 0 14px 30px -18px rgba(16, 33, 58, .45);
}
.chat-bar {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 16px 18px; background: var(--verify); color: #fff;
}
.chat-title { font-weight: 700; font-size: 1.1rem; line-height: 1.35; }
.timer { font-weight: 700; font-size: 1.5rem; font-variant-numeric: tabular-nums; }
.timer.low { color: #FFD9D6; }
.chat-meta {
  display: flex; align-items: center; gap: 12px; flex-wrap: wrap;
  padding: 10px 18px; border-bottom: 1px solid var(--line); font-size: .9rem; color: var(--muted);
}
.who { display: inline-flex; align-items: center; gap: 7px; color: var(--ink); font-weight: 700; }
.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--caught); }
.log {
  list-style: none; margin: 0; padding: 16px 18px;
  display: flex; flex-direction: column; gap: 8px;
  height: 300px; overflow-y: auto; scroll-behavior: smooth;
}
.msg { max-width: 78%; padding: 8px 13px; font-size: 1rem; line-height: 1.45; overflow-wrap: anywhere; }
.msg.them { align-self: flex-start; background: #fff; border: 1px solid var(--line); border-radius: 3px 14px 14px 14px; }
.msg.me { align-self: flex-end; background: #E4ECFF; border: 1px solid #C2D2FF; border-radius: 14px 3px 14px 14px; }
.msg.sys { align-self: center; max-width: none; padding: 2px 0; color: var(--muted); font-size: .88rem; }
.typing { align-self: flex-start; color: var(--muted); font-size: .88rem; display: flex; align-items: center; gap: 6px; }
.typing i { width: 5px; height: 5px; border-radius: 50%; background: currentColor; animation: blink 1s infinite; }
.typing i:nth-child(2) { animation-delay: .15s; }
.typing i:nth-child(3) { animation-delay: .3s; }
@keyframes blink { 50% { opacity: .2; } }
.composer { display: flex; gap: 8px; margin: 0; padding: 12px 18px 4px; border-top: 1px solid var(--line); }
.composer input {
  flex: 1; min-width: 0; padding: 10px 12px; font: inherit; font-size: .95rem; color: var(--ink);
  background: #fff; border: 1px solid #9AA6B4; border-radius: 3px;
}
.composer input:disabled { background: #F1F3F5; border-color: var(--line); }
.composer input::placeholder { color: #7A8597; }
.send {
  padding: 0 18px; border: 0; border-radius: 3px; background: var(--verify); color: #fff; font-weight: 700; cursor: pointer;
}
.send:hover:not(:disabled) { background: var(--verify-dark); }
.send:disabled { background: #E3E7EB; color: #7A8597; cursor: default; }
.note { min-height: 1.9em; padding: 2px 18px 8px; font-size: .85rem; color: var(--fooled); }

/* guess */
.guess { padding: 16px 18px 18px; border-top: 1px solid var(--line); }
.guess-head { font-weight: 700; font-size: 1.1rem; margin-bottom: 12px; }
.guess-left { margin-left: 6px; font-weight: 400; font-size: .9rem; color: var(--muted); font-variant-numeric: tabular-nums; }
.tiles { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.tile {
  position: relative; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 4px;
  min-height: 136px; padding: 12px; cursor: pointer;
  background: var(--scan); border: 2px solid transparent; border-radius: 2px;
  transition: transform .12s, border-color .12s;
}
.tile:hover { border-color: #9AA6B4; }
.tile-art { width: 70%; max-width: 200px; height: auto; }
.tile-art text { font: 500 64px var(--scanned); fill: #15181e; text-anchor: middle; }
.tile-label { font-weight: 700; font-size: 1rem; }
.tile[aria-pressed="true"] { transform: scale(.94); border-color: var(--verify); background: #D4DDF2; }
.tile-check {
  position: absolute; top: -9px; left: -9px; width: 28px; height: 28px; border-radius: 50%;
  background: var(--verify) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M6 12.5l4 4 8-9' fill='none' stroke='%23fff' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / 18px no-repeat;
  opacity: 0; transform: scale(.6); transition: opacity .12s, transform .12s;
}
.tile[aria-pressed="true"] .tile-check { opacity: 1; transform: scale(1); }
.guess-foot { display: flex; align-items: center; justify-content: flex-end; gap: 12px; margin-top: 14px; }
.verify {
  padding: 11px 30px; border: 0; border-radius: 2px; cursor: pointer;
  background: var(--verify); color: #fff; font-weight: 700; font-size: 1.05rem;
}
.verify:hover:not(:disabled) { background: var(--verify-dark); }
.verify:disabled { opacity: .4; cursor: not-allowed; }

/* reveal */
.reveal { padding: 26px 18px 22px; border-top: 1px solid var(--line); text-align: center; }
.stamp {
  display: inline-block; padding: 4px 20px; transform: rotate(-5deg);
  border: 4px solid currentColor; border-radius: 4px;
  font-weight: 700; font-size: 2.1rem; line-height: 1.3;
}
.stamp.fooled { color: var(--fooled); }
.stamp.caught { color: var(--caught); }
.stamp.none { color: var(--muted); }
.stamp.hit { animation: stamp .32s cubic-bezier(.2, 1.4, .4, 1) both; }
@keyframes stamp { from { opacity: 0; transform: rotate(-5deg) scale(1.7); } }
.reveal-text { margin: 18px auto 0; max-width: 44ch; font-size: 1.05rem; }
.reveal-sub { margin: 6px auto 0; max-width: 44ch; color: var(--muted); font-size: .92rem; }
.card {
  width: min(400px, 100%); margin: 20px auto 0; background: #fff; border: 1px solid var(--line); border-radius: 3px;
  box-shadow: 0 10px 24px -16px rgba(16, 33, 58, .45); text-align: left;
}
.card-art { display: block; width: 100%; height: auto; }
.card-art text { font: 500 58px var(--scanned); fill: #15181e; text-anchor: middle; }
.card-art text.zh { font: 700 52px var(--scanned-zh); }
.card figcaption { display: flex; justify-content: space-between; gap: 12px; padding: 8px 12px; font-size: .85rem; color: var(--muted); }
.card-url { font-weight: 700; color: var(--ink); }
.reveal-actions { margin-top: 18px; display: flex; justify-content: center; flex-wrap: wrap; gap: 10px; }
.share {
  padding: 9px 18px; border-radius: 3px; background: var(--ink); color: #fff; font-weight: 700; text-decoration: none;
}
.share:hover { background: #000; }
.again {
  padding: 9px 18px; cursor: pointer;
  background: var(--card); border: 1px solid var(--line); border-radius: 3px; font-weight: 700;
}
.again:hover { border-color: var(--ink); }

/* counter */
.counter {
  margin-top: 6px; overflow: hidden; position: sticky; top: 20px;
  background: var(--card); border: 1px solid var(--line); border-radius: 4px;
  box-shadow: 0 10px 24px -18px rgba(16, 33, 58, .35);
}
.counter-head { padding: 13px 16px; background: var(--verify); color: #fff; font-weight: 700; font-size: 1rem; }
.grid { display: grid; grid-template-columns: repeat(10, 1fr); gap: 4px; padding: 14px 16px 6px; }
.grid span { aspect-ratio: 1; background: #fff; border: 1.5px solid var(--line); border-radius: 2px; }
.grid span.hit {
  background: var(--fooled) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M5 12.5l4.5 4.5L19 7' fill='none' stroke='%23fff' stroke-width='3.2' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / 80% no-repeat;
  border-color: var(--fooled);
}
.counter-line { padding: 10px 16px 0; font-size: 1.45rem; font-weight: 700; line-height: 1.25; }
.counter-line b { color: var(--fooled); font-variant-numeric: tabular-nums; }
.counter-note { padding: 6px 16px 0; font-size: .88rem; color: var(--muted); }
.counter-live { margin: 12px 16px 16px; padding-top: 10px; border-top: 1px solid var(--line); font-size: .8rem; color: var(--muted); }

/* below the fold */
.how, .notes { max-width: 1160px; margin: 0 auto; padding: 0 24px; }
.how { margin-top: 80px; }
.how h2, .notes h2 { font-size: 1.5rem; font-weight: 700; }
.steps { list-style: none; margin: 20px 0 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.steps li { border-top: 2px solid var(--ink); padding-top: 14px; }
.steps .n { display: block; font: 500 2.6rem/1 var(--scanned); color: var(--verify); }
.steps h3 { margin-top: 8px; font-size: 1.2rem; }
.steps p { margin-top: 6px; color: var(--muted); max-width: 34ch; }
.notes { margin-top: 72px; display: grid; grid-template-columns: 1fr 1fr; gap: 56px; }
.rules ul { list-style: none; margin: 16px 0 0; padding: 0; display: grid; gap: 12px; }
.rules li {
  padding-left: 34px; max-width: 46ch;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Crect x='2' y='2' width='20' height='20' rx='2' fill='%23fff' stroke='%23C4CAD1' stroke-width='2'/%3E%3Cpath d='M6.5 12.5l3.5 3.5 7.5-8' fill='none' stroke='%230B8F55' stroke-width='2.6' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") 0 .15em / 22px no-repeat;
}
.why p { margin-top: 14px; max-width: 50ch; }
.why .why-ask { font-weight: 700; font-size: 1.2rem; }
.foot {
  max-width: 1160px; margin: 88px auto 0; padding: 24px 24px 40px; border-top: 1px solid var(--line);
  display: grid; gap: 6px; font-size: .9rem; color: var(--muted);
}
.foot-brand { color: var(--ink); font-weight: 700; }
.ca-soon { padding: 0 7px; border: 1px dashed #8E99A7; border-radius: 2px; }

@media (max-width: 880px) {
  .hero { grid-template-columns: minmax(0, 1fr); gap: 20px; padding-top: 12px; }
  .counter { position: static; margin-top: 4px; }
  .check-row { grid-template-columns: auto minmax(0, 1fr); gap: 14px; }
  .fine { grid-column: 1 / -1; border-left: 0; border-top: 1px solid var(--line); padding: 10px 0 0; }
  .steps { grid-template-columns: 1fr; gap: 20px; }
  .notes { grid-template-columns: 1fr; gap: 40px; }
  .how { margin-top: 56px; }
}
@media (max-width: 520px) {
  body { font-size: 16px; }
  .top { padding: 14px 16px; }
  .brand-zh { display: none; }
  .hero, .how, .notes { padding-left: 16px; padding-right: 16px; }
  .widget { padding: 8px; margin-top: 20px; }
  .words-art { display: none; }
  .words-art.stacked { display: block; }
  .check-row { padding: 12px 6px 4px; }
  .check-label { font-size: 1.1rem; }
  .chat-bar { padding: 13px 14px; }
  .chat-title { font-size: 1rem; }
  .chat-meta, .log, .composer, .note, .guess { padding-left: 14px; padding-right: 14px; }
  .log { height: 280px; }
  .tile { min-height: 116px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; scroll-behavior: auto !important; }
}
html:not(:lang(zh-CN)) .only-zh, html:lang(zh-CN) .only-en { display: none; }