/* reSkill v2, editorial. Paper + indigo, Geist + Instrument Serif.
   Light default; dark via html.dark or prefers-color-scheme. */

:root,
html.light {
  --paper: #f7f5ef;
  --paper-warm: #efece3;
  --paper-soft: #f2f0ea;
  --paper-warmer: #e3e0d6;
  --ink: #0e0e12;
  --ink-soft: #2a2a33;
  --mute: #8a8a93;
  --rule: #dad7cc;
  --rule-soft: #eceae2;
  --rule-strong: #c2bfb2;
  --indigo: #513def;
  --indigo-soft: #513def24;
  --shadow-1: 0 1px 0 0 #0000000f;
  --shadow-2: 0 40px 60px -40px #0e0e1233;
  --grid-ink: #0e0e1208;
}

html.dark,
body.dark {
  --paper: #14141a;
  --paper-warm: #1b1b22;
  --paper-soft: #181820;
  --paper-warmer: #24242c;
  --ink: #ececea;
  --ink-soft: #c7c6c0;
  --mute: #7d7c85;
  --rule: #2b2b32;
  --rule-soft: #22222a;
  --rule-strong: #3a3a42;
  --indigo: #8a7bff;
  --indigo-soft: #8a7bff28;
  --shadow-1: 0 1px 0 0 #ffffff08;
  --shadow-2: 0 40px 60px -40px #00000080;
  --grid-ink: #ececea10;
}

:root {
  --font-sans: "Geist", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  --font-mono: "Geist Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --font-serif: "Instrument Serif", ui-serif, Georgia, "Times New Roman", serif;
  --max: 1140px;
  --gutter: clamp(1.25rem, 4vw, 2rem);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  position: relative;
  min-height: 100vh;
  overflow-x: hidden;
  transition: background 180ms ease, color 180ms ease;
}

/* paper grid backdrop, single quiet 48px grid that fades out near the fold */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image:
    linear-gradient(to right, var(--grid-ink) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-ink) 1px, transparent 1px);
  background-size: 48px 48px;
  -webkit-mask-image: linear-gradient(to bottom, black 0, black 50%, transparent 90%);
  mask-image: linear-gradient(to bottom, black 0, black 50%, transparent 90%);
}

body > * { position: relative; z-index: 1; }

::selection { background: var(--indigo-soft); color: var(--ink); }

a { color: inherit; }
a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--indigo);
  outline-offset: 3px;
  border-radius: 3px;
}

code, kbd { font-family: var(--font-mono); }
.tabnum { font-variant-numeric: tabular-nums; }

/* ───── masthead ───── */
.ed-mast {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.55rem var(--gutter);
  border-top: 1px solid var(--ink);
  border-bottom: 1px solid var(--rule);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 1.5rem;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--mute);
  letter-spacing: 0.06em;
  margin-top: 1.5rem;
  margin-bottom: 2rem;
}
.ed-mast .l { text-align: left; }
.ed-mast .r {
  text-align: right;
  display: inline-flex;
  gap: 0.75rem;
  justify-content: flex-end;
  align-items: center;
}
.ed-mast .title {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 28px;
  color: var(--ink);
  letter-spacing: -0.02em;
  text-align: center;
}
.ed-mast .title i { font-style: normal; color: var(--indigo); }

.theme-toggle {
  background: transparent;
  border: 1px solid var(--rule);
  border-radius: 999px;
  padding: 3px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink-soft);
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: border-color 150ms ease, color 150ms ease;
}
.theme-toggle:hover { border-color: var(--ink); color: var(--ink); }

/* ───── hero ───── */
.ed-hero {
  max-width: var(--max);
  margin: 0 auto 3rem;
  padding: 0 var(--gutter);
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  gap: 3rem;
  align-items: start;
}
.ed-issue {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--mute);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin: 0 0 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.ed-issue::before {
  content: "";
  width: 28px;
  height: 1px;
  background: var(--ink);
}
.ed-h1 {
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: clamp(60px, 9.5vw, 136px);
  line-height: 0.88;
  letter-spacing: -0.045em;
  color: var(--ink);
  margin: 0 0 1.5rem;
}
.ed-h1 em { font-style: italic; color: var(--indigo); }
.ed-h1 em.ink { color: var(--ink); }
.ed-deck {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 24px;
  line-height: 1.35;
  color: var(--ink-soft);
  max-width: 34ch;
  margin: 0 0 1.75rem;
}
.ed-byline {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--mute);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  align-items: center;
}
.ed-byline b { color: var(--ink); font-weight: 500; }
.ed-byline .dot {
  width: 3px;
  height: 3px;
  background: var(--rule-strong);
  border-radius: 50%;
}

/* figure */
.ed-fig { position: relative; }
.ed-fig-cap {
  margin-top: 0.9rem;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--mute);
  letter-spacing: 0.04em;
  line-height: 1.55;
}
.ed-fig-cap b {
  color: var(--ink);
  font-weight: 500;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 14px;
  letter-spacing: 0;
}

/* ───── three-step strip ───── */
.ed-strip {
  max-width: var(--max);
  margin: 0 auto 2.5rem;
  padding: 1.25rem var(--gutter);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}
.ed-step {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1rem;
}
.ed-step .n {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 56px;
  line-height: 0.85;
  color: var(--indigo);
  letter-spacing: -0.02em;
}
.ed-step b {
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: 17px;
  letter-spacing: -0.012em;
  color: var(--ink);
  display: block;
  margin-bottom: 0.25rem;
}
.ed-step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.55;
  color: var(--ink-soft);
}

/* ───── close strip ───── */
.ed-close {
  max-width: var(--max);
  margin: 0 auto;
  padding: 1rem var(--gutter) 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: end;
}
.ed-close .pull {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: clamp(28px, 3.4vw, 40px);
  line-height: 1.15;
  letter-spacing: -0.015em;
  color: var(--ink);
  margin: 0;
  max-width: 22ch;
}
.install-wrap {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  max-width: 460px;
  margin-left: auto;
}
.install-wrap .lbl {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--mute);
}
.install-wrap .lbl-sub {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--mute);
  margin: 0;
}
.install-wrap .lbl-sub code {
  background: var(--paper-warm);
  border: 1px solid var(--rule);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--ink-soft);
}

/* ───── install block ───── */
.install {
  background: var(--paper-warm);
  border: 1px solid var(--rule);
  border-radius: 10px;
  padding: 12px 12px 12px 16px;
  font-family: var(--font-mono);
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 12px;
  overflow: hidden;
  box-shadow: var(--shadow-1);
}
.install-cmd {
  flex: 1;
  min-width: 0;
  overflow-x: auto;
  white-space: nowrap;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--ink);
  display: flex;
  align-items: baseline;
  gap: 0.5em;
}
.install-sigil { color: var(--mute); user-select: none; }
.install-cursor {
  display: inline-block;
  width: 8px;
  height: 1em;
  background: var(--indigo);
  vertical-align: -2px;
  margin-left: 2px;
  animation: blink 1.05s steps(1, end) infinite;
  flex: none;
}
@keyframes blink { 50% { opacity: 0; } }
.install-copy {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-soft);
  background: var(--paper);
  border: 1px solid var(--rule);
  padding: 6px 10px;
  border-radius: 6px;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}
.install-copy:hover { border-color: var(--ink); color: var(--ink); }
.install-copy.copied { border-color: var(--indigo); color: var(--indigo); }

/* ───── quiz pane (demo) ───── */
.quiz-pane {
  margin: 0;
  background: var(--paper-soft);
  border: 1px solid var(--rule);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow-1), var(--shadow-2);
}
.quiz-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--mute);
  padding: 9px 14px;
  background: var(--paper-warm);
  border-bottom: 1px solid var(--rule);
}
.quiz-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--indigo);
  box-shadow: 0 0 0 3px var(--indigo-soft);
}
.quiz-title { color: var(--ink-soft); font-weight: 500; }
.quiz-bar-sep { color: var(--rule-strong); }
.quiz-bar-spacer { flex: 1; }
.quiz-meta { color: var(--mute); }
.quiz-meta.thinking { color: var(--ink-soft); }
.quiz-body { padding: 22px 22px 18px; }
.quiz-context {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--mute);
  margin-bottom: 0.85rem;
}
.quiz-prompt {
  font-family: var(--font-sans);
  font-size: 19px;
  line-height: 1.35;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin-bottom: 1.1rem;
  max-width: 52ch;
}
.quiz-options {
  list-style: none;
  padding: 0;
  margin: 0 0 1rem;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.quiz-opt button {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 12px;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 9px 12px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--ink-soft);
  text-align: left;
  transition: background 0.12s, border-color 0.12s, color 0.12s;
}
.quiz-opt button:hover:not(:disabled) {
  background: var(--paper-warm);
  border-color: var(--rule);
  color: var(--ink);
}
.quiz-opt button:disabled { cursor: default; }
.opt-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  flex: none;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--mute);
  background: var(--paper);
  border: 1px solid var(--rule);
  border-radius: 5px;
}
.opt-text { flex: 1; min-width: 0; }
.opt-mark {
  flex: none;
  font-size: 14px;
  width: 18px;
  text-align: right;
  color: var(--mute);
}
.quiz-opt.right button {
  background: var(--paper-warm);
  border-color: var(--indigo);
  color: var(--ink);
}
.quiz-opt.right .opt-num {
  background: var(--indigo);
  color: #fff;
  border-color: var(--indigo);
}
.quiz-opt.right .opt-mark { color: var(--indigo); }
.quiz-opt.wrong button {
  background: var(--paper-warm);
  border-color: var(--rule-strong);
  color: var(--ink-soft);
}
.quiz-opt.wrong .opt-mark { color: var(--ink); }
.quiz-opt.dim button { color: var(--mute); }
.quiz-explain {
  display: flex;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--ink-soft);
  background: var(--paper);
  border: 1px dashed var(--rule);
  border-radius: 6px;
  padding: 10px 12px;
  margin-bottom: 1rem;
  line-height: 1.5;
}
.quiz-explain-label {
  color: var(--mute);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  flex: none;
}
.quiz-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--mute);
  padding-top: 0.25rem;
}
.quiz-footer .sep { color: var(--rule-strong); }
.quiz-link {
  background: transparent;
  border: 0;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--mute);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 5px;
}
.quiz-link:hover { color: var(--ink); }
.quiz-link.primary { color: var(--ink); }

kbd {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1;
  padding: 3px 6px;
  min-width: 18px;
  text-align: center;
  background: var(--paper);
  border: 1px solid var(--rule);
  border-bottom-width: 2px;
  border-radius: 4px;
  color: var(--ink-soft);
  margin: 0 1px;
  vertical-align: 1px;
}

/* ───── colophon ───── */
.ed-colophon {
  max-width: var(--max);
  margin: 2.5rem auto 2rem;
  padding: 1rem var(--gutter) 0;
  border-top: 1px solid var(--rule);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--mute);
  letter-spacing: 0.04em;
}
.colophon-links {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
}
.colophon-links .dot {
  width: 3px;
  height: 3px;
  background: var(--rule-strong);
  border-radius: 50%;
  display: inline-block;
}
.ed-colophon a {
  color: var(--ink-soft);
  text-decoration: none;
  border-bottom: 1px solid var(--rule-strong);
  padding-bottom: 1px;
  transition: color 150ms ease, border-color 150ms ease;
}
.ed-colophon a:hover { color: var(--indigo); border-color: var(--indigo); }

/* ───── responsive ───── */
@media (max-width: 880px) {
  .ed-hero,
  .ed-strip,
  .ed-close {
    grid-template-columns: 1fr;
    gap: 1.75rem;
  }
  .ed-mast {
    grid-template-columns: auto 1fr;
    gap: 0.75rem;
    text-align: left;
    font-size: 10.5px;
    padding: 0.5rem var(--gutter);
  }
  .ed-mast .title { display: none; }
  .ed-h1 {
    font-size: clamp(56px, 14vw, 96px);
    letter-spacing: -0.04em;
  }
  .ed-deck { font-size: 20px; }
  .ed-close { align-items: start; }
  .install-wrap { margin-left: 0; max-width: none; }
  .ed-close .pull { font-size: clamp(24px, 6.5vw, 32px); }
  .ed-step .n { font-size: 44px; }
  .ed-fig-cap { font-size: 10.5px; }
  .ed-colophon { font-size: 10.5px; gap: 0.5rem; }
}

@media (max-width: 520px) {
  .quiz-body { padding: 18px 16px 16px; }
  .quiz-prompt { font-size: 17px; }
}

@media (prefers-reduced-motion: reduce) {
  .install-cursor { animation: none; }
  * { transition: none !important; }
}