/* SliceFocus — landing page.
   Visual language modeled on claude.ai / anthropic.com (ADR-042 "minimal & sincere"):
   warm cream canvas, Anthropic clay accent, large literary serif headlines (Fraunces
   ≈ "Anthropic Serif"), a clean humanist sans (Inter ≈ "Anthropic Sans"), generous
   whitespace, a dark pill CTA. The product is the hero; saturation lives in the
   real app screenshots, not the page chrome. */

:root {
  --bg:        #f0eee6;  /* the signature Anthropic cream canvas */
  --surface:   #faf9f5;  /* lifted paper — screenshot frames */
  --fg:        #141413;  /* warm near-black */
  --muted:     #6f6e66;  /* warm grey, secondary text */
  --faint:     #8a897f;  /* warm grey, tertiary text */
  --accent:    #d97757;  /* Anthropic clay / coral */
  --accent-ink:#c4623f;  /* deeper clay for hover */
  --line:      #e3dacc;  /* warm hairline rules / borders */
  --btn:       #141413;  /* dark pill button */
  --btn-fg:    #faf9f5;
  --btn-hover: #2b2a26;
  --shadow: 0 28px 60px -28px rgba(38, 30, 20, 0.30);

  --serif: "Fraunces", "Iowan Old Style", "Palatino Linotype", Georgia, ui-serif, serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg:        #1a1916;
    --surface:   #22201c;
    --fg:        #ece7dd;
    --muted:     #a8a297;
    --faint:     #8d877c;
    --accent:    #e08a6b;
    --accent-ink:#ef9d80;
    --line:      #33302a;
    --btn:       #ece7dd;
    --btn-fg:    #1a1916;
    --btn-hover: #fffdf8;
    --shadow: 0 28px 60px -28px rgba(0, 0, 0, 0.6);
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 1.0625rem;        /* ~17px */
  line-height: 1.62;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* ---- Containers: a wide shell for the nav, a narrow column for reading ---- */
.shell { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 24px; }
.wrap  { width: 100%; max-width: 660px;  margin: 0 auto; padding: 0 24px; }

/* ---- Typography ---- */
h1, h2, h3 {
  font-family: var(--serif);
  font-weight: 500;
  color: var(--fg);
  line-height: 1.08;
  letter-spacing: -0.018em;
  font-variation-settings: "opsz" 144, "SOFT" 0, "WONK" 0;
}
h1 { font-size: clamp(2.7rem, 7vw, 4.1rem); margin: 0 0 0.36em; }
h2 { font-size: clamp(1.7rem, 4.2vw, 2.3rem); margin: 0 0 0.6rem; line-height: 1.12; }

p { margin: 0 0 1.1rem; }

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid var(--line);  /* fallback for browsers without color-mix() */
  border-bottom: 1px solid color-mix(in srgb, var(--accent) 35%, transparent);
}
a:hover { color: var(--accent-ink); border-bottom-color: var(--accent-ink); }

.lede {
  font-size: clamp(1.15rem, 2.4vw, 1.35rem);
  line-height: 1.5;
  color: var(--muted);
  max-width: 36ch;
  margin: 0 auto;
}

.eyebrow {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 1rem;
}

/* ---- Dark pill button (echoes claude.ai's "Try Claude") ---- */
.btn-dark {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--btn);
  color: var(--btn-fg);
  font-family: var(--sans);
  font-size: 0.95rem;
  font-weight: 500;
  line-height: 1;
  padding: 10px 18px;
  border: 0;
  border-radius: 10px;
  white-space: nowrap;
  transition: background 0.15s ease, transform 0.15s ease;
}
.btn-dark:hover { background: var(--btn-hover); color: var(--btn-fg); border: 0; transform: translateY(-1px); }

/* ---- Header / nav ---- */
.site-header { padding: 22px 0; }
.nav { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--serif);
  font-weight: 500;
  font-size: 1.3rem;
  letter-spacing: -0.01em;
  color: var(--fg);
  border: 0;
  font-variation-settings: "opsz" 40, "SOFT" 0, "WONK" 0;
}
.wordmark img { display: block; }

/* ---- Hero ---- */
.hero { text-align: center; padding: clamp(56px, 10vw, 108px) 0 clamp(44px, 8vw, 80px); }

/* Portrait product screen: rounded corners + soft shadow, centered on cream.
   No device bezel (ADR-042) — the real app screenshot is the hero. */
.hero-media {
  width: min(330px, 76vw);
  margin: clamp(40px, 6vw, 60px) auto 0;
  border-radius: 30px;
  overflow: hidden;
  background: var(--surface);
  box-shadow: var(--shadow);  /* fallback for browsers without color-mix() */
  box-shadow: var(--shadow), 0 0 0 1px color-mix(in srgb, var(--fg) 8%, transparent);
}
.hero-media img { display: block; width: 100%; height: auto; }

/* ---- App Store badge (official Apple artwork) ---- */
.appstore {
  display: inline-flex;
  margin-top: clamp(30px, 5vw, 42px);
  border: 0;
  border-radius: 9px;
  transition: opacity 0.15s ease, transform 0.15s ease;
}
.appstore:hover { opacity: 0.85; transform: translateY(-1px); }
.appstore img { display: block; height: 52px; width: auto; }

/* ---- Section rhythm ---- */
section { padding: clamp(48px, 8vw, 88px) 0; }
.section-divider { border-top: 1px solid var(--line); }

/* How it works + science intros read centered and airy, like claude.ai. */
.how, .science { text-align: center; }
.how p { max-width: 48ch; margin-left: auto; margin-right: auto; color: var(--fg); }
.science > .wrap > p { max-width: 48ch; margin-left: auto; margin-right: auto; }

/* ---- Secondary product shot (focus timer in "How it works") ---- */
.shot { width: min(290px, 68vw); margin: clamp(30px, 5vw, 46px) auto 0; }
.shot img,
.shot video {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 30px;
  background: var(--surface);
  box-shadow: var(--shadow);  /* fallback for browsers without color-mix() */
  box-shadow: var(--shadow), 0 0 0 1px color-mix(in srgb, var(--fg) 8%, transparent);
}
.shot figcaption {
  margin: 1.1rem auto 0;
  max-width: 38ch;
  font-size: 0.92rem;
  color: var(--muted);
  line-height: 1.5;
}

/* ---- Features accordion (native <details>, no JS) ---- */
.features { text-align: center; }
.feature-list {
  max-width: 600px;
  margin: clamp(28px, 5vw, 46px) auto 0;
  text-align: left;
}
.feature { border-top: 1px solid var(--line); }
.feature:last-child { border-bottom: 1px solid var(--line); }

.feature > summary {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.2rem;
  padding: clamp(15px, 3vw, 21px) 2px;
  cursor: pointer;
  list-style: none;                 /* Firefox: drop the disclosure triangle */
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(1.12rem, 2.4vw, 1.3rem);
  line-height: 1.25;
  letter-spacing: -0.012em;
  color: var(--fg);
  transition: color 0.15s ease;
  -webkit-tap-highlight-color: transparent;
}
.feature > summary::-webkit-details-marker { display: none; }   /* Safari/Chrome */
.feature > summary:hover { color: var(--accent); }
.feature > summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 6px;
}

/* Chevron marker: points down when collapsed, flips up when open */
.feature-marker {
  flex: 0 0 auto;
  width: 10px;
  height: 10px;
  margin-top: 0.4em;
  border-right: 2px solid var(--faint);
  border-bottom: 2px solid var(--faint);
  border-radius: 1px;
  transform: rotate(45deg);
  transition: transform 0.22s ease, border-color 0.15s ease;
}
.feature[open] .feature-marker { transform: rotate(-135deg); }
.feature > summary:hover .feature-marker { border-color: var(--accent); }

.feature-body { padding: 0 2px clamp(18px, 4vw, 28px); }
.feature-body p { color: var(--muted); margin: 0 0 0.4rem; }
.feature-body .shot { margin-top: clamp(18px, 4vw, 28px); }
.feature-soon {
  font-size: 0.92rem;
  font-style: italic;
  color: var(--faint);
}

@media (prefers-reduced-motion: reduce) {
  .feature-marker { transition: border-color 0.15s ease; }
}

/* ---- Science claims ---- */
.science .claims {
  list-style: none;
  max-width: 560px;
  margin: 1.7rem auto 0;
  padding: 0;
  text-align: left;
}
.science .claims li {
  padding: 1.2rem 0;
  border-top: 1px solid var(--line);
}
.science .claims li:last-child { border-bottom: 1px solid var(--line); }
.science .claim { margin: 0 0 0.3rem; font-size: 1.08rem; }
.science .cite { margin: 0; font-size: 0.9rem; color: var(--muted); }
.science .cite a { font-size: inherit; }
.science-note { margin-top: 1.7rem; font-size: 0.92rem; color: var(--faint); }

/* ---- Footer ---- */
.site-footer {
  text-align: center;
  padding: 56px 0 72px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.88rem;
}
.site-footer a { color: var(--muted); border-bottom-color: var(--line); }
.site-footer a:hover { color: var(--fg); }
.site-footer .links { margin-bottom: 0.6rem; }
.site-footer .links a { margin: 0 10px; }

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
  /* Don't shift interactive elements on hover for reduced-motion users. */
  .btn-dark:hover,
  .appstore:hover { transform: none; }
}