/* Tacit 2 on the web: white page, #F4F4F4 panels at 6 px, black rules and buttons, no shadows. */
@font-face { font-family: 'IBM Plex Sans'; font-weight: 400; font-style: normal; font-display: swap; src: url('/assets/fonts/IBMPlexSans-Regular.woff2') format('woff2'); }
@font-face { font-family: 'IBM Plex Sans'; font-weight: 500; font-style: normal; font-display: swap; src: url('/assets/fonts/IBMPlexSans-Medium.woff2') format('woff2'); }
@font-face { font-family: 'IBM Plex Sans'; font-weight: 600; font-style: normal; font-display: swap; src: url('/assets/fonts/IBMPlexSans-SemiBold.woff2') format('woff2'); }
@font-face { font-family: 'IBM Plex Sans'; font-weight: 700 800; font-style: normal; font-display: swap; src: url('/assets/fonts/IBMPlexSans-Bold.woff2') format('woff2'); }
@font-face { font-family: 'IBM Plex Mono'; font-weight: 400; font-style: normal; font-display: swap; src: url('/assets/fonts/IBMPlexMono-Regular.woff2') format('woff2'); }
@font-face { font-family: 'IBM Plex Mono'; font-weight: 500; font-style: normal; font-display: swap; src: url('/assets/fonts/IBMPlexMono-Medium.woff2') format('woff2'); }
@font-face { font-family: 'IBM Plex Mono'; font-weight: 600; font-style: normal; font-display: swap; src: url('/assets/fonts/IBMPlexMono-SemiBold.woff2') format('woff2'); }

:root {
  color-scheme: light;
  --page: #ffffff;
  --panel: #f4f4f4;
  --ink: #111111;
  --text: #333333;
  --muted: #666666;
  --line: #dddddd;
  --image-line: #e5e5e5;
  --radius: 6px;
  --rule: 3px;
  --max: 1080px;
  --gutter: 16px;
  --sans: 'IBM Plex Sans', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --mono: 'IBM Plex Mono', ui-monospace, 'SF Mono', Menlo, monospace;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--page);
  color: var(--ink);
  font: 400 17px/1.5 var(--sans);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  /* the footer sits at the bottom of a short page (the studio page is one screen) */
  min-height: 100vh; min-height: 100svh;
  display: flex; flex-direction: column;
}
main { flex: 1 0 auto; }
img { max-width: 100%; height: auto; }
a { color: inherit; }

h1, h2, h3 { font-weight: 700; margin: 0; }
h1 { font-size: clamp(34px, 6vw, 56px); line-height: 1.04; letter-spacing: -0.025em; }
h2 { font-size: clamp(26px, 4vw, 36px); line-height: 1.1; letter-spacing: -0.02em; }
h3 { font-size: 22px; line-height: 1.2; letter-spacing: -0.015em; }
p { margin: 0 0 1em; color: var(--text); }

.container { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 var(--gutter); }
.data-label { font: 500 11px/1.4 var(--mono); text-transform: uppercase; letter-spacing: 0.08em; }
.num, .mono { font-family: var(--mono); }
.visually-hidden {
  position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; }
.skip { position: absolute; left: var(--gutter); top: -100px; background: var(--ink); color: #fff; padding: 8px 12px; border-radius: var(--radius); z-index: 10; }
.skip:focus { top: 8px; }

/* header */
.site-header { background: var(--panel); }
.header-row { display: flex; justify-content: space-between; align-items: center; min-height: 60px; }
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; }
.brand-mark { display: block; width: 32px; height: 32px; }
.wordmark { font-weight: 800; font-size: 22px; letter-spacing: -0.02em; }
.lang-switch { font: 500 13px var(--mono); color: var(--muted); }
.lang-switch a { display: inline-flex; align-items: center; justify-content: center; min-width: 44px; min-height: 44px; text-decoration: none; padding: 0 4px; }
.lang-switch a:hover { color: var(--ink); }
.lang-current { color: var(--ink); font-weight: 600; border-bottom: 2px solid var(--ink); }

/* sections, panels, rules */
main { display: block; padding-bottom: 64px; }
.rule { border: 0; border-top: var(--rule) solid var(--ink); margin: 0; }
.section { border-top: var(--rule) solid var(--ink); padding: 40px 0 56px; }
.panel { background: var(--panel); border-radius: var(--radius); padding: 24px; }
.shot { display: block; border-radius: 26px; border: 1px solid var(--image-line); background: var(--page); }

/* buttons and form */
.button, .waitlist button {
  display: inline-flex; align-items: center; justify-content: center;
  border: 0; border-radius: var(--radius);
  background: var(--ink); color: #fff;
  font: 600 15px var(--sans); padding: 14px 22px; min-height: 48px;
  cursor: pointer; text-decoration: none;
}
.button:hover, .waitlist button:hover { background: #333; }
.waitlist button:disabled { background: #666; cursor: progress; }

.waitlist { max-width: 460px; }
.waitlist-row { display: flex; border: 1.5px solid var(--ink); border-radius: var(--radius); overflow: hidden; background: var(--page); }
.waitlist-row:focus-within { outline: 2px solid var(--ink); outline-offset: 2px; }
.waitlist input[type=email] {
  flex: 1; min-width: 0; border: 0; border-radius: 0; background: transparent;
  padding: 14px 16px; font: 400 16px var(--sans); color: var(--ink); outline: none;
}
.waitlist-row button { border-radius: 0; }
.waitlist .hp { position: absolute; left: -10000px; width: 1px; height: 1px; overflow: hidden; }
.form-status { min-height: 1.5em; margin: 10px 0 0; font-size: 15px; }
.form-status[data-kind=invalid], .form-status[data-kind=unavailable] { color: #b00020; }
.form-status[data-kind=ok] { color: var(--ink); font-weight: 500; }
.signup-ok { display: none; margin: 10px 0 0; font-weight: 500; color: var(--ink); }
.signup-ok:target { display: block; }
.fine { font: 400 12px/1.5 var(--mono); color: var(--muted); }

/* footer */
.site-footer { background: var(--ink); color: #fff; font-size: 15px; }
.footer-row { display: flex; flex-direction: column; gap: 16px; padding-top: 32px; padding-bottom: 36px; }
.footer-nav { display: flex; gap: 24px; }
.footer-nav a { text-decoration: none; border-bottom: 1px solid #777; }
.footer-nav a:hover { border-color: #fff; }
.footer-note { margin: 0; color: #bbb; text-transform: none; letter-spacing: 0.02em; }
.site-footer :focus-visible { outline-color: #fff; }

@media (min-width: 900px) {
  :root { --gutter: 40px; }
  .section { padding: 64px 0 88px; }
  .footer-row { flex-direction: row; justify-content: space-between; align-items: center; }
}

/* ---- landing page ---- */
.section h2 { margin-bottom: 14px; }
.section .eyebrow { color: #555; margin: 0 0 10px; }
h2.eyebrow { font: 500 11px/1.4 var(--mono); letter-spacing: 0.08em; }
.section > h2:not(.eyebrow) + p, .label-intro p, .plans-head > p { max-width: 34em; }

/* hero (C2): screenshot on grey, then a black rule, headline, sentence, form */
.hero-panel {
  background: var(--panel);
  margin: 0 calc(-1 * var(--gutter));
  padding: 16px 40px 0;
  height: 340px; height: clamp(260px, 42svh, 380px);
  overflow: hidden;
  display: flex; justify-content: center; align-items: flex-start;
}
.hero-shot { width: 100%; max-width: 300px; border-radius: 26px 26px 0 0; }
.hero-copy { border-top: var(--rule) solid var(--ink); padding: 20px 0 24px; }
.hero h1 { margin-bottom: 12px; }
.lead { font-size: 17px; margin-bottom: 18px; }
.waitlist .fine { margin: 10px 0 0; }
.waitlist input::placeholder { color: #767676; opacity: 1; }

/* the label */
.label-intro { margin-bottom: 24px; }
.facts { border: 2px solid var(--ink); padding: 10px 12px 4px; max-width: 400px; background: var(--page); }
.facts table { width: 100%; border-collapse: collapse; }
.facts caption { text-align: left; padding-bottom: 6px; }
.facts-title { display: block; font-weight: 800; font-size: 28px; line-height: 1; letter-spacing: -0.02em; }
.facts-sub { display: block; font-size: 13px; margin-top: 4px; }
.facts th, .facts td { border-top: 1px solid var(--ink); padding: 6px 0; font-size: 14px; vertical-align: top; }
.facts th { text-align: left; font-weight: 700; padding-right: 12px; }
.facts td { text-align: right; font-family: var(--mono); font-size: 13px; white-space: nowrap; }
.facts .light th { font-weight: 400; }
.facts .thick > * { border-top-width: 7px; }

/* four features: text beside a small screenshot on phones, grey cards on wide screens */
.features { display: grid; }
.feature { display: grid; grid-template-columns: minmax(0, 1fr) 120px; gap: 16px; align-items: center; padding: 20px 0; border-top: 1px solid var(--line); }
.feature:first-child { border-top: 0; padding-top: 8px; }
.feature h3 { font-size: 18px; margin-bottom: 6px; }
.feature p { font-size: 15px; margin: 0; }
.feature .shot { width: 120px; border-radius: 14px; }

/* free and premium */
.plans { display: grid; gap: 40px; margin-top: 8px; }
.plan-title { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; border-bottom: var(--rule) solid var(--ink); padding-bottom: 10px; font-size: 20px; }
.plan-title .num { font-size: 14px; font-weight: 600; white-space: nowrap; }
.plan-list, .prices { margin: 0; }
.plan-list div, .prices div { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; padding: 11px 0; border-bottom: 1px solid var(--line); }
.plan-list dt, .prices dt { font-size: 16px; }
.plan-list dd, .prices dd { margin: 0; font: 500 14px var(--mono); text-align: right; white-space: nowrap; }
.prices { margin-top: 24px; padding: 4px 20px; }
.prices div:last-child { border-bottom: 0; }
.prices dd { font-weight: 600; font-size: 15px; }
.plan-after { margin: 16px 0 0; }

/* the note */
.note { margin: 20px 0 0; padding: 28px 24px; }
.note blockquote { margin: 0; }
.note blockquote p { margin: 0; font-size: 22px; line-height: 1.35; font-weight: 500; letter-spacing: -0.01em; color: var(--ink); }
.note figcaption { margin-top: 18px; font-weight: 600; }

/* sign-up again */
.signup { padding-bottom: 24px; }
.signup h2 { margin-bottom: 20px; }

@media (min-width: 900px) {
  .section .eyebrow { font-size: 12px; }

  .hero { display: grid; grid-template-columns: minmax(0, 1fr) clamp(340px, 42vw, 460px); gap: clamp(40px, 6vw, 72px); align-items: center; padding: 56px 0 72px; }
  .hero-panel { grid-column: 2; grid-row: 1; margin: 0; border-radius: var(--radius); height: 600px; padding-top: 52px; }
  .hero-shot { width: 340px; max-width: 100%; border-radius: 30px 30px 0 0; }
  .hero-copy { grid-column: 1; grid-row: 1; padding: 28px 0 0; }
  .hero h1 { font-size: clamp(48px, 5.4vw, 68px); line-height: 1.02; margin-bottom: 22px; }
  .lead { font-size: 19px; max-width: 470px; margin-bottom: 30px; }

  .label-section { display: grid; grid-template-columns: minmax(0, 1fr) 400px; gap: clamp(48px, 8vw, 96px); align-items: start; }
  .label-intro { margin: 0; }
  .facts { padding: 14px 16px 6px; }
  .facts-title { font-size: 34px; }
  .facts-sub { font-size: 14px; }
  .facts th, .facts td { padding: 7px 0; font-size: 15px; }
  .facts td { font-size: 14px; }
  .facts .thick > * { border-top-width: 8px; }

  .features { grid-template-columns: 1fr 1fr; gap: 24px; margin-top: 24px; }
  .feature, .feature:first-child { display: flex; flex-direction: column; background: var(--panel); border: 0; border-radius: var(--radius); padding: 36px 40px 0; overflow: hidden; }
  .feature h3 { font-size: 24px; margin-bottom: 8px; }
  .feature p { font-size: 16px; max-width: 420px; }
  .feature-crop { margin-top: 36px; height: 380px; overflow: hidden; display: flex; justify-content: center; align-items: flex-start; }
  .feature .shot { width: 280px; border-radius: 24px 24px 0 0; }
  /* the check-in sheet sits at the bottom of its screenshot, so that card crops from the top */
  .feature.from-bottom .feature-crop { height: 340px; margin-bottom: 40px; align-items: flex-end; }
  .feature.from-bottom .shot { border-radius: 0 0 24px 24px; }
  /* the weight chart is a wide crop: full card width, natural height */
  .feature.chart { justify-content: center; }
  .feature.chart .feature-crop { height: auto; margin-bottom: 40px; }
  .feature.chart .shot { width: 100%; border-radius: 8px; }

  .plans-head { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 64px; align-items: end; margin-bottom: 40px; }
  .plans-head > p { margin: 0; }
  .plans-head h2 { margin-bottom: 0; }
  .plans { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 64px; align-items: start; }
  .prices { margin-top: 28px; }
  .plan-after { margin-top: 18px; }

  .about { text-align: center; }
  .about > *, .about > .eyebrow { max-width: 680px; margin-left: auto; margin-right: auto; }
  .note { margin-top: 28px; padding: 48px 56px; }
  .note blockquote p { font-size: 28px; }
  .note figcaption { margin-top: 24px; }

  .signup { padding-bottom: 48px; display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 64px; align-items: center; }
  .signup h2 { margin: 0; font-size: 40px; }
}

/* ---- support and privacy: one readable column ---- */
.doc { max-width: 680px; padding-top: 40px; }
.doc-head { border-bottom: var(--rule) solid var(--ink); padding-bottom: 20px; margin-bottom: 28px; }
.doc-head .eyebrow { color: #555; margin: 0 0 10px; }
.doc h1 { font-size: clamp(34px, 6vw, 48px); }
.doc-date { margin: 14px 0 0; color: var(--muted); }
.doc-box { margin-bottom: 8px; }
.doc-box p:last-child { margin-bottom: 0; }
.doc section { padding-top: 32px; }
.doc h2 { font-size: 22px; line-height: 1.2; letter-spacing: -0.015em; margin-bottom: 10px; }
.doc h3 { font-size: 17px; line-height: 1.3; letter-spacing: 0; margin: 22px 0 6px; }
.doc ul { margin: 0 0 1em; padding-left: 22px; color: var(--text); }
.doc li { margin-bottom: 6px; }
.doc li::marker { color: var(--ink); }
.doc a { text-underline-offset: 2px; overflow-wrap: anywhere; }
.doc code { font: 400 0.88em var(--mono); background: var(--panel); border-radius: 3px; padding: 1px 4px; color: var(--ink); }
.doc strong, .ui { font-weight: 600; color: var(--ink); }

@media (min-width: 900px) {
  .doc { padding-top: 64px; }
  .doc-head { padding-bottom: 28px; margin-bottom: 36px; }
  .doc section { padding-top: 40px; }
  .doc h2 { font-size: 26px; }
}

/* ---- studio page (tacit-software.com): one calm screen ---- */
.studio { padding: 40px 0 48px; }
.studio h1 { border-top: var(--rule) solid var(--ink); padding-top: 20px; max-width: 15em; font-size: clamp(32px, 6vw, 60px); }
.studio .nowrap { white-space: nowrap; }
.studio-card { display: flex; align-items: center; gap: 16px; margin-top: 40px; max-width: 520px; text-decoration: none; }
.studio-card:hover { background: #ececec; }
.studio-card-mark { flex: none; width: 56px; height: 56px; }
.studio-card-text { display: flex; flex-direction: column; gap: 2px; min-width: 0; flex: 1; }
.studio-card-name { font-weight: 700; font-size: 20px; letter-spacing: -0.015em; color: var(--ink); }
.studio-card-line { color: var(--text); font-size: 16px; }
.studio-card-when { margin-top: 6px; color: #555; }
.studio-card-arrow { flex: none; font: 500 22px var(--mono); color: var(--ink); }

@media (min-width: 900px) {
  .studio { padding: 80px 0 80px; }
  .studio h1 { padding-top: 32px; line-height: 1.06; }
  .studio-card { margin-top: 64px; padding: 28px 32px; gap: 20px; }
  .studio-card-mark { width: 64px; height: 64px; }
  .studio-card-name { font-size: 22px; }
}