/* ==========================================================================
   Fonts — self-hosted Geist, SIL Open Font License (see fonts/OFL.txt)
   ========================================================================== */

@font-face {
  font-family: "Geist";
  font-weight: 100 900;
  font-display: swap;
  src: url("fonts/geist.woff2") format("woff2");
}

@font-face {
  font-family: "Geist Mono";
  font-weight: 100 900;
  font-display: swap;
  src: url("fonts/geist-mono.woff2") format("woff2");
}

/* ==========================================================================
   Tokens — every color is light-dark(light, dark).
   The theme follows the system; the toggle pins it via [data-theme].
   ========================================================================== */

:root {
  color-scheme: light dark;

  --bg:         light-dark(#fafaf9, #0b0b0b);
  --surface:    light-dark(#ffffff, #121212);
  --soft:       light-dark(#f3f3f1, #191919);
  --fg:         light-dark(#0c0c0c, #ededed);
  --text:       light-dark(#3d3d3b, #b8b8b5);
  --muted:      light-dark(#6b6b68, #8e8e8a);
  --faint:      light-dark(#a1a19c, #5e5e5b);
  --line:       light-dark(#e6e5e1, #232322);
  --red:        light-dark(#d92d20, #f97066);
  --red-soft:   light-dark(rgb(217 45 32 / 8%), rgb(249 112 102 / 10%));
  --green:      light-dark(#15803d, #4ade80);
  --green-soft: light-dark(rgb(21 128 61 / 9%), rgb(74 222 128 / 9%));

  --sans: "Geist", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "Geist Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --ease: 0.15s ease;
}

:root[data-theme="light"] { color-scheme: light; }
:root[data-theme="dark"]  { color-scheme: dark; }

/* ==========================================================================
   Base
   ========================================================================== */

*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 24px;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 400 16px/1.65 var(--sans);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color 0.2s ease, color 0.2s ease;
}

::selection { background: var(--fg); color: var(--bg); }

a { color: inherit; }

h1, h2, p, ul { margin: 0; }

h1, h2 {
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

:focus-visible {
  outline: 2px solid var(--fg);
  outline-offset: 3px;
  border-radius: 6px;
}

.wrap {
  max-width: 720px;
  margin-inline: auto;
  padding-inline: 24px;
}

.skip-link {
  position: absolute;
  top: -60px;
  left: 16px;
  z-index: 10;
  padding: 10px 14px;
  border-radius: 8px;
  background: var(--fg);
  color: var(--bg);
  font-size: 14px;
  text-decoration: none;
}
.skip-link:focus { top: 16px; }

/* ==========================================================================
   Buttons
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  height: 44px;
  padding: 0 20px;
  border: 1px solid transparent;
  border-radius: 999px;
  background: var(--fg);
  color: var(--bg);
  font: 500 15px/1 var(--sans);
  text-decoration: none;
  cursor: pointer;
  transition: opacity var(--ease), background-color var(--ease);
}
.btn:hover { opacity: 0.85; }
.btn:active { transform: translateY(1px); }

.btn-ghost {
  min-width: 92px;
  height: 32px;
  padding: 0 14px;
  border-color: var(--line);
  background: transparent;
  color: var(--fg);
  font-size: 13px;
}
.btn-ghost:hover {
  opacity: 1;
  background: var(--soft);
}

.btn-icon {
  min-width: 0;
  width: 36px;
  height: 36px;
  padding: 0;
}
.btn-icon svg { width: 16px; height: 16px; }

/* ==========================================================================
   Header
   ========================================================================== */

.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
  text-decoration: none;
}
.brand-mark { width: 20px; height: 20px; }
.brand-mark rect { fill: var(--fg); }
.brand-mark path { stroke: var(--bg); }

/* ==========================================================================
   Hero
   ========================================================================== */

.hero {
  padding: clamp(72px, 14vw, 140px) 0 clamp(72px, 11vw, 112px);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 28px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 12.5px;
}
.eyebrow::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--green);
}

/* "no ___" — the phrase is typed, erased and struck through by main.js */
.title {
  display: flex;
  align-items: baseline;
  gap: 0.22em;
  margin-bottom: 24px;
  font-size: clamp(2.75rem, 12.5vw, 5.75rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.055em;
  white-space: nowrap;
}

.strike {
  position: relative;
  color: var(--faint);
}
.strike::after {
  content: "";
  position: absolute;
  top: 54%;
  right: -0.04em;
  left: -0.04em;
  height: 0.07em;
  min-height: 3px;
  border-radius: 999px;
  background: var(--red);
  transform-origin: left center;
  transition: transform 0.45s cubic-bezier(0.65, 0, 0.35, 1);
}
.strike.is-clear::after {
  transform: scaleX(0);
  transition-duration: 0.2s;
}

.caret {
  align-self: center;
  width: 0.06em;
  min-width: 3px;
  height: 0.82em;
  margin-left: -0.16em;
  border-radius: 2px;
  background: var(--fg);
  animation: blink 1.1s steps(1) infinite;
}

@keyframes blink { 50% { opacity: 0; } }

.subtitle {
  max-width: 36em;
  margin-bottom: 36px;
  color: var(--muted);
  font-size: 1.0625rem;
  line-height: 1.6;
  text-wrap: pretty;
}

/* ==========================================================================
   Sections
   ========================================================================== */

.section {
  padding: 72px 0;
  border-top: 1px solid var(--line);
}

.section-head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 20px;
}
.section-head h2 {
  font-size: clamp(1.5rem, 3.4vw, 1.9rem);
  letter-spacing: -0.03em;
}

.num {
  color: var(--faint);
  font-family: var(--mono);
  font-size: 13px;
}

.prose {
  margin-bottom: 20px;
  color: var(--text);
}
.prose p + p { margin-top: 14px; }

.note {
  margin-top: 32px;
  padding: 16px 18px;
  border-radius: 12px;
  background: var(--soft);
  color: var(--text);
  font-size: 15px;
}
.note strong {
  color: var(--fg);
  font-weight: 600;
}

/* ==========================================================================
   Chat mock
   ========================================================================== */

.chat {
  margin-bottom: 28px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface);
}

.chat-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 18px;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 12.5px;
}

.pill {
  padding: 3px 9px;
  border-radius: 999px;
  font-size: 11.5px;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}
.pill-no  { color: var(--red);   background: var(--red-soft); }
.pill-yes { color: var(--green); background: var(--green-soft); }

.chat-body {
  display: grid;
  gap: 18px;
  padding: 20px 18px;
}

.msg {
  display: flex;
  gap: 12px;
}

.avatar {
  flex: none;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--soft);
  color: var(--muted);
  font-size: 13px;
  font-weight: 600;
}

.msg-meta {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 14px;
  line-height: 1.5;
}
.msg-meta b { font-weight: 600; }
.msg-meta time {
  color: var(--faint);
  font-family: var(--mono);
  font-size: 11.5px;
}

.msg-text {
  font-size: 15px;
  line-height: 1.5;
}

/* ==========================================================================
   Example lines
   ========================================================================== */

.lines {
  display: grid;
  gap: 10px;
  padding: 0;
  list-style: none;
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.5;
}
.lines li {
  display: flex;
  align-items: baseline;
  gap: 12px;
}
.lines li::before {
  flex: none;
  font-size: 12px;
}

.lines-no li { color: var(--muted); }
.lines-no li::before { content: "✕"; color: var(--red); }
.lines-no s {
  text-decoration-color: var(--red);
  text-decoration-thickness: 1.5px;
}

.lines-yes li::before { content: "✓"; color: var(--green); }

/* ==========================================================================
   Footer
   ========================================================================== */

.foot {
  display: grid;
  gap: 20px;
  padding: 32px 0 56px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13.5px;
}

.foot-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 16px;
}

.foot-share {
  color: var(--fg);
  font-size: 15px;
  font-weight: 500;
}

.foot-links {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 16px;
}
.foot-links a {
  text-decoration: none;
  transition: color var(--ease);
}
.foot-links a:hover { color: var(--fg); }

/* ==========================================================================
   Responsive & motion
   ========================================================================== */

@media (max-width: 560px) {
  .wrap { padding-inline: 16px; }
  .section { padding: 56px 0; }
  .chat-head { padding-inline: 14px; }
  .chat-body { padding: 18px 14px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  body, .btn, .foot-links a, .strike::after { transition: none; }
  .caret { animation: none; }
}