/* chatgptwatermark.app: the page is a loupe held over text. Paper, ink, and two meaning colours:
   green = a watermark "green-list" word, coral = a character you cannot see. */
@font-face { font-family: "Newsreader"; src: url(/fonts/Newsreader-normal-400-700.woff2) format("woff2"); font-weight: 400 700; font-style: normal; font-display: swap; }
@font-face { font-family: "Newsreader"; src: url(/fonts/Newsreader-italic-400-600.woff2) format("woff2"); font-weight: 400 600; font-style: italic; font-display: swap; }
@font-face { font-family: "Public Sans"; src: url(/fonts/PublicSans-normal-400-700.woff2) format("woff2"); font-weight: 400 700; font-display: swap; }
@font-face { font-family: "JetBrains Mono"; src: url(/fonts/JetBrainsMono-normal-400.woff2) format("woff2"); font-weight: 400 600; font-display: swap; }

:root {
  --paper: #f3f0e8;
  --paper-2: #ebe6da;
  --card: #fbfaf6;
  --ink: #16150f;
  --ink-2: #3c3a32;
  --muted: #6a665a;
  --rule: #d6cfbf;
  --green: #17734a;
  --green-bg: #d5eadb;
  --coral: #d9481f;
  --coral-bg: #fbd8c9;
  --focus: #17734a;
  --serif: "Newsreader", "Iowan Old Style", Georgia, serif;
  --sans: "Public Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --r: 14px;
  --gutter: clamp(16px, 4vw, 40px);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #11110e; --paper-2: #191814; --card: #1c1b17; --ink: #f1ede2; --ink-2: #d2cdbf; --muted: #a09a8a;
    --rule: #34322b; --green: #5cc790; --green-bg: #173726; --coral: #ff8a62; --coral-bg: #48210f; --focus: #5cc790;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #11110e; --paper-2: #191814; --card: #1c1b17; --ink: #f1ede2; --ink-2: #d2cdbf; --muted: #a09a8a;
  --rule: #34322b; --green: #5cc790; --green-bg: #173726; --coral: #ff8a62; --coral-bg: #48210f; --focus: #5cc790;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 400 17px/1.6 var(--sans); overflow-x: hidden; }
a { color: inherit; text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--green); }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 3px; border-radius: 4px; }
img, svg { max-width: 100%; }
.wrap { width: 100%; max-width: 1140px; margin: 0 auto; padding: 0 var(--gutter); }
.mono { font-family: var(--mono); font-size: 0.82em; letter-spacing: 0.02em; }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 16px; background: var(--ink); color: var(--paper); padding: 8px 12px; z-index: 10; }

/* ---------- Header ---------- */
.top { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 18px 0; }
.brand { display: flex; align-items: center; gap: 10px; font: 600 18px/1 var(--serif); text-decoration: none; letter-spacing: -0.01em; }
.brand svg { width: 28px; height: 28px; flex: none; }
.brand b { font-weight: 600; }
.brand i { font-style: italic; color: var(--green); font-weight: 500; }
.nav { display: flex; align-items: center; gap: 18px; font-size: 15px; }
.nav a { text-decoration: none; color: var(--ink-2); }
.nav a:hover { color: var(--ink); }
.nav .acct { border: 1px solid var(--ink); border-radius: 999px; padding: 7px 14px; color: var(--ink); }
.theme-btn { background: none; border: 1px solid var(--rule); border-radius: 999px; width: 34px; height: 34px; color: var(--ink); cursor: pointer; display: grid; place-items: center; }
@media (max-width: 640px) { .nav .hide-s { display: none; } .nav { gap: 12px; } }

/* ---------- Hero ---------- */
.hero { padding: clamp(18px, 4vw, 46px) 0 10px; }
.eyebrow { font: 500 13px/1.3 var(--mono); text-transform: uppercase; letter-spacing: 0.12em; color: var(--muted); margin: 0 0 14px; display: flex; align-items: center; gap: 10px; }
.eyebrow::before { content: ""; width: 26px; height: 1px; background: var(--muted); }
h1 { font: 500 clamp(42px, 6.6vw, 88px)/0.95 var(--serif); letter-spacing: -0.035em; margin: 0; max-width: 13ch; }
h1 em { font-style: italic; color: var(--green); font-weight: 400; }
.lede { font: 400 clamp(19px, 2.1vw, 23px)/1.45 var(--serif); color: var(--ink-2); max-width: 40ch; margin: 22px 0 0; }
.lede strong { color: var(--ink); font-weight: 600; }
.hero-grid { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: clamp(20px, 4vw, 56px); align-items: end; }
@media (max-width: 880px) { .hero-grid { grid-template-columns: 1fr; } }

/* The loupe: a specimen line where hidden characters develop under a lens on load */
.specimen { position: relative; background: var(--card); border: 1px solid var(--rule); border-radius: var(--r); padding: 18px 18px 14px; box-shadow: 0 1px 0 var(--rule); }
.specimen p { margin: 0; font: 400 18px/1.75 var(--serif); }
.specimen .cap { display: flex; justify-content: space-between; font: 500 12px/1 var(--mono); color: var(--muted); margin-top: 12px; text-transform: uppercase; letter-spacing: 0.08em; }
.hc { display: inline-block; font: 600 10px/1 var(--mono); color: var(--coral); background: var(--coral-bg); border-radius: 4px; padding: 3px 4px; margin: 0 2px; vertical-align: 2px; letter-spacing: 0.04em; }
.specimen .hc { opacity: 0; transform: translateY(3px); animation: develop 420ms var(--ease) forwards; }
.specimen .hc:nth-of-type(1) { animation-delay: 0.3s; } .specimen .hc:nth-of-type(2) { animation-delay: 0.5s; }
.specimen .hc:nth-of-type(3) { animation-delay: 0.7s; } .specimen .hc:nth-of-type(4) { animation-delay: 0.9s; }
@media (max-width: 600px) { .specimen { display: none; } }
@keyframes develop { to { opacity: 1; transform: none; } }

/* ---------- Tool ---------- */
.tool { margin: clamp(26px, 4vw, 44px) 0 0; background: var(--card); border: 1.5px solid var(--ink); border-radius: calc(var(--r) + 4px); overflow: hidden; }
.tool-tabs { display: flex; border-bottom: 1.5px solid var(--ink); }
.tool-tabs button { flex: 1; font: 600 15px/1.2 var(--sans); padding: 15px 12px; background: var(--paper-2); color: var(--ink-2); border: 0; cursor: pointer; display: flex; gap: 8px; align-items: center; justify-content: center; }
.tool-tabs button + button { border-left: 1.5px solid var(--ink); }
.tool-tabs button[aria-selected="true"] { background: var(--card); color: var(--ink); box-shadow: inset 0 -3px 0 var(--green); }
.tool-tabs .tag { font: 600 11px/1 var(--mono); border-radius: 999px; padding: 4px 7px; background: var(--green-bg); color: var(--green); }
.tool-body { display: grid; grid-template-columns: 1fr 1fr; min-height: 360px; }
.pane { padding: 16px; display: flex; flex-direction: column; gap: 10px; min-width: 0; }
.pane + .pane { border-left: 1px solid var(--rule); }
.pane-h { display: flex; justify-content: space-between; align-items: center; font: 500 12px/1 var(--mono); text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); }
textarea { width: 100%; flex: 1; min-height: 260px; resize: vertical; border: 1px solid var(--rule); border-radius: 10px; background: var(--paper); color: var(--ink); padding: 14px; font: 400 16px/1.6 var(--sans); }
textarea:focus { outline: 2px solid var(--focus); outline-offset: 0; }
.out { flex: 1; min-height: 260px; border: 1px dashed var(--rule); border-radius: 10px; padding: 14px; overflow: auto; white-space: pre-wrap; word-break: break-word; font: 400 16px/1.6 var(--sans); color: var(--ink); }
.out:empty::before { content: attr(data-empty); color: var(--muted); }
.row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; justify-content: space-between; }
.btn { appearance: none; border: 1.5px solid var(--ink); background: var(--ink); color: var(--paper); font: 600 15px/1 var(--sans); padding: 13px 18px; border-radius: 999px; cursor: pointer; transition: transform 140ms var(--ease), background 140ms; text-decoration: none; display: inline-flex; align-items: center; gap: 8px; }
.btn:hover { transform: translateY(-2px); color: var(--paper); }
.btn:active { transform: scale(0.97); }
.btn:disabled { opacity: 0.5; cursor: wait; transform: none; }
.btn.alt { background: transparent; color: var(--ink); }
.btn.alt:hover { color: var(--ink); background: var(--paper-2); }
.btn.green { background: var(--green); border-color: var(--green); color: #fff; }
.meta { font: 500 13px/1.4 var(--mono); color: var(--muted); }
.found { display: flex; flex-wrap: wrap; gap: 6px; font-size: 14px; }
.found .chip { font: 500 12px/1 var(--mono); border: 1px solid var(--coral); color: var(--coral); border-radius: 999px; padding: 5px 9px; }
.found .ok { color: var(--green); border-color: var(--green); }
.status { font-size: 14px; color: var(--ink-2); min-height: 20px; }
.status.err { color: var(--coral); }
.bar { height: 3px; background: var(--rule); border-radius: 3px; overflow: hidden; }
.bar i { display: block; height: 100%; width: 30%; background: var(--green); animation: slide 1.6s var(--ease) infinite; }
@keyframes slide { from { transform: translateX(-100%); } to { transform: translateX(340%); } }
@media (max-width: 760px) { .tool-tabs button { font-size: 14px; padding: 13px 8px; } .tool-tabs .tag { display: none; } .tool-body { grid-template-columns: 1fr; } .pane + .pane { border-left: 0; border-top: 1px solid var(--rule); } }

/* ---------- TL;DR + sections ---------- */
.tldr { margin: clamp(34px, 5vw, 56px) 0 0; display: grid; grid-template-columns: 180px 1fr; gap: 24px; border-top: 1.5px solid var(--ink); padding-top: 20px; }
.tldr h2 { font: 600 13px/1.3 var(--mono); text-transform: uppercase; letter-spacing: 0.12em; margin: 4px 0 0; color: var(--muted); }
.tldr p { margin: 0; font: 400 clamp(19px, 2vw, 22px)/1.5 var(--serif); max-width: 62ch; }
@media (max-width: 700px) { .tldr { grid-template-columns: 1fr; gap: 8px; } }

section.q { padding: clamp(46px, 7vw, 86px) 0 0; }
.q-head { display: grid; grid-template-columns: 180px 1fr; gap: 24px; align-items: baseline; }
.q-num { font: 600 13px/1 var(--mono); color: var(--green); letter-spacing: 0.08em; }
h2 { font: 500 clamp(30px, 4.2vw, 50px)/1.05 var(--serif); letter-spacing: -0.02em; margin: 0; max-width: 20ch; }
h3 { font: 600 19px/1.3 var(--sans); margin: 26px 0 6px; }
.q-body { display: grid; grid-template-columns: 180px 1fr; gap: 24px; margin-top: 18px; }
.q-body > div { max-width: 68ch; }
.q-body p { margin: 0 0 14px; }
.capsule { font: 400 21px/1.5 var(--serif); color: var(--ink); }
.src { font: 500 12.5px/1.5 var(--mono); color: var(--muted); }
.src a { color: var(--muted); }
@media (max-width: 700px) { .q-head, .q-body { grid-template-columns: 1fr; gap: 8px; } .q-body > aside { display: none; } }

/* two-layer diagram */
.layers { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin: 18px 0; }
.layer { border: 1px solid var(--rule); border-radius: var(--r); padding: 16px; background: var(--card); }
.layer h3 { margin-top: 0; }
.layer .verdict { font: 600 12px/1 var(--mono); text-transform: uppercase; letter-spacing: 0.08em; }
.layer.a .verdict { color: var(--coral); } .layer.b .verdict { color: var(--green); }
@media (max-width: 640px) { .layers { grid-template-columns: 1fr; } }

/* figures table */
table.fig { width: 100%; border-collapse: collapse; margin: 14px 0 6px; font-size: 15px; }
.fig th, .fig td { text-align: left; padding: 10px 8px; border-bottom: 1px solid var(--rule); }
.fig th { font: 600 12px/1.2 var(--mono); text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); }
.fig td.n { font: 600 22px/1 var(--serif); }
.meterline { height: 8px; background: var(--paper-2); border-radius: 8px; overflow: hidden; min-width: 80px; }
.meterline i { display: block; height: 100%; background: var(--green); border-radius: 8px; }

/* ---------- Green-list demo ---------- */
.demo { margin-top: 20px; background: var(--card); border: 1.5px solid var(--ink); border-radius: calc(var(--r) + 4px); padding: clamp(16px, 3vw, 26px); }
.demo-text { font: 400 19px/1.95 var(--serif); margin: 0 0 16px; }
.demo-text span { border-radius: 4px; padding: 1px 2px; transition: background 220ms, color 220ms; }
.demo-text .g { background: var(--green-bg); color: var(--green); }
.demo-text .r { background: transparent; color: var(--ink-2); text-decoration: underline dotted var(--muted); text-underline-offset: 4px; }
.demo-text .sw { box-shadow: inset 0 -2px 0 var(--coral); }
.demo-ctl { display: grid; grid-template-columns: 1fr auto; gap: 18px; align-items: center; border-top: 1px solid var(--rule); padding-top: 16px; }
.demo-ctl label { font: 600 14px/1.3 var(--sans); display: block; margin-bottom: 6px; }
input[type=range] { width: 100%; accent-color: var(--green); }
.gauge { text-align: right; min-width: 170px; }
.gauge .z { font: 500 44px/1 var(--serif); }
.gauge .v { font: 600 12px/1.3 var(--mono); text-transform: uppercase; letter-spacing: 0.08em; }
.gauge .v.hit { color: var(--green); } .gauge .v.miss { color: var(--coral); }
.demo-legend { display: flex; flex-wrap: wrap; gap: 14px; font-size: 13.5px; color: var(--muted); margin-top: 12px; }
.demo-legend b { font-weight: 600; }
@media (max-width: 600px) { .demo-ctl { grid-template-columns: 1fr; } .gauge { text-align: left; } }

/* ---------- Pricing ---------- */
.plans { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-top: 18px; }
.plan { border: 1px solid var(--rule); border-radius: var(--r); padding: 20px; background: var(--card); display: flex; flex-direction: column; gap: 10px; }
.plan.feat { border: 1.5px solid var(--ink); box-shadow: 6px 6px 0 var(--green-bg); }
.plan h3 { margin: 0; font: 600 20px/1.2 var(--serif); }
.price { font: 500 46px/1 var(--serif); letter-spacing: -0.02em; }
.price small { font: 400 15px/1 var(--sans); color: var(--muted); letter-spacing: 0; }
.plan ul { list-style: none; padding: 0; margin: 4px 0 8px; font-size: 15px; }
.plan li { padding: 5px 0; border-bottom: 1px dotted var(--rule); }
.plan .btn { justify-content: center; margin-top: auto; }
.plan .fine { font-size: 12.5px; color: var(--muted); }
@media (max-width: 860px) { .plans { grid-template-columns: 1fr; } }

.plans.four { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 1000px) { .plans.four { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) { .plans.four { grid-template-columns: 1fr; } }
.billing-toggle { display: inline-flex; border: 1.5px solid var(--ink); border-radius: 999px; padding: 3px; margin-top: 18px; gap: 2px; }
.billing-toggle button { border: 0; background: none; color: var(--ink-2); font: 600 14px/1 var(--sans); padding: 9px 14px; border-radius: 999px; cursor: pointer; }
.billing-toggle button[aria-pressed="true"] { background: var(--ink); color: var(--paper); }
.billing-toggle .save { font: 600 11px/1 var(--mono); color: var(--green); margin-left: 4px; }
.billing-toggle button[aria-pressed="true"] .save { color: var(--green-bg); }

/* ---------- Footer ---------- */
footer { margin-top: clamp(60px, 9vw, 110px); border-top: 1.5px solid var(--ink); padding: 26px 0 40px; font-size: 14px; color: var(--ink-2); }
.foot { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 24px; }
.foot h4 { font: 600 12px/1 var(--mono); text-transform: uppercase; letter-spacing: 0.1em; color: var(--muted); margin: 0 0 10px; }
.foot ul { list-style: none; padding: 0; margin: 0; }
.foot li { margin: 0 0 6px; }
.legal-line { margin-top: 22px; font-size: 12.5px; color: var(--muted); max-width: 90ch; }
@media (max-width: 700px) { .foot { grid-template-columns: 1fr; } }

/* ---------- Dialog ---------- */
dialog { border: 1.5px solid var(--ink); border-radius: 18px; padding: 22px; max-width: 420px; width: calc(100% - 32px); background: var(--card); color: var(--ink); }
dialog::backdrop { background: rgb(15 14 10 / 0.55); }
dialog h2 { font-size: 30px; margin-bottom: 6px; }
dialog p { margin: 0 0 14px; color: var(--ink-2); font-size: 15px; }
dialog input { width: 100%; font: 400 17px/1.3 var(--sans); padding: 12px 14px; border-radius: 10px; border: 1px solid var(--rule); background: var(--paper); color: var(--ink); margin-bottom: 12px; }
dialog input.code { font: 600 26px/1 var(--mono); letter-spacing: 0.4em; text-align: center; }
dialog .x { position: absolute; top: 12px; right: 12px; background: none; border: 0; font-size: 22px; cursor: pointer; color: var(--muted); }
dialog [data-signin-msg] { color: var(--coral); font-size: 14px; min-height: 18px; margin: 0; }
.linkbtn { background: none; border: 0; color: var(--ink-2); text-decoration: underline; cursor: pointer; font: inherit; font-size: 14px; padding: 0; }

/* ---------- Legal/account pages ---------- */
.doc { max-width: 760px; padding-top: 20px; }
.doc h1 { font-size: clamp(40px, 6vw, 64px); max-width: none; margin-bottom: 8px; }
.doc h2 { font-size: 26px; margin: 34px 0 8px; max-width: none; }
.doc p, .doc li { color: var(--ink-2); }
.acct-card { border: 1.5px solid var(--ink); border-radius: var(--r); padding: 20px; background: var(--card); margin: 18px 0; }
.acct-card .big { font: 500 52px/1 var(--serif); }

.reveal { opacity: 0; transform: translateY(16px); transition: opacity 420ms var(--ease), transform 420ms var(--ease); }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .specimen .hc { animation: none; opacity: 1; transform: none; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .bar i { animation: none; width: 100%; opacity: 0.4; }
  .btn, .btn:hover { transform: none; }
  .demo-text span { transition: none; }
}