/* TutorBoard — marketing site
   Palette derives from the app icon + Play feature graphic:
   navy ink, classroom blue, marker pink, chalk orange. */

:root {
  --ink: #0a1a35;
  --ink-2: #12294d;
  --blue: #1e5fd0;
  --blue-soft: #e8f0fe;
  --pink: #e6265f;
  --pink-soft: #fdeaf1;
  --orange: #f59e0b;
  --orange-soft: #fef3e2;
  --green: #10905a;

  --text: #16233b;
  --muted: #5b6b85;
  --line: #e4e9f2;
  --bg: #ffffff;
  --bg-alt: #f6f8fc;

  --radius: 18px;
  --radius-lg: 28px;
  --shadow-sm: 0 1px 2px rgba(10, 26, 53, .06), 0 4px 12px rgba(10, 26, 53, .05);
  --shadow: 0 12px 32px rgba(10, 26, 53, .10), 0 2px 8px rgba(10, 26, 53, .05);
  --shadow-lg: 0 32px 80px rgba(10, 26, 53, .22);

  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
          "Helvetica Neue", Arial, sans-serif;
  --maxw: 1140px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 88px; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* height:auto is load-bearing — the width/height attributes on <img> would
   otherwise force each image to its intrinsic pixel height and squash it. */
img { max-width: 100%; height: auto; display: block; }

a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3 { line-height: 1.15; letter-spacing: -0.022em; margin: 0 0 .5em; }
h1 { font-size: clamp(2.05rem, 4vw, 3.02rem); font-weight: 800; }
h2 { font-size: clamp(1.75rem, 3.4vw, 2.6rem); font-weight: 800; }
h3 { font-size: 1.18rem; font-weight: 700; }
p { margin: 0 0 1rem; }

.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

.section { padding: 96px 0; }
.section--alt { background: var(--bg-alt); border-block: 1px solid var(--line); }

.eyebrow {
  display: inline-block;
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .13em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 14px;
}

.section-head { max-width: 680px; margin: 0 auto 56px; text-align: center; }
.section-head p { color: var(--muted); font-size: 1.1rem; margin: 0; }

.lead { font-size: 1.15rem; color: var(--muted); }

/* ── Header ─────────────────────────────────────────────── */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, .82);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s ease, box-shadow .2s ease;
}
.header.is-stuck { border-bottom-color: var(--line); box-shadow: var(--shadow-sm); }

.nav { display: flex; align-items: center; gap: 18px; height: 72px; }

.brand { display: flex; align-items: center; gap: 11px; font-weight: 800; color: var(--ink); letter-spacing: -.02em; }
.brand:hover { text-decoration: none; }
.brand img { width: 34px; height: 34px; border-radius: 9px; }
.brand span { font-size: 1.16rem; }

.nav-links { display: flex; gap: 30px; margin-left: auto; }
.nav-links a {
  color: var(--muted);
  font-weight: 600;
  font-size: .95rem;
  text-decoration: none;
  transition: color .15s ease;
}
.nav-links a:hover { color: var(--ink); }

/* ── Buttons ────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 26px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 1rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .15s ease, box-shadow .2s ease, background .2s ease;
  text-decoration: none;
  white-space: nowrap;
}
.btn:hover { text-decoration: none; transform: translateY(-2px); }

.btn--play {
  background: linear-gradient(135deg, var(--pink), #ff5c8a);
  color: #fff;
  box-shadow: 0 10px 28px rgba(230, 38, 95, .38);
}
.btn--play:hover { box-shadow: 0 16px 38px rgba(230, 38, 95, .46); }
.btn--play svg { width: 20px; height: 22px; flex: none; }
.btn--play small { display: block; font-size: .66rem; font-weight: 600; opacity: .85; letter-spacing: .06em; text-transform: uppercase; line-height: 1.2; }
.btn--play strong { display: block; font-size: 1.02rem; line-height: 1.2; }

.btn--ghost-light {
  background: rgba(255, 255, 255, .07);
  color: #fff;
  border-color: rgba(255, 255, 255, .28);
}
.btn--ghost-light:hover { background: rgba(255, 255, 255, .14); }

.btn--nav {
  padding: 10px 20px;
  font-size: .92rem;
  background: var(--ink);
  color: #fff;
}
.btn--nav:hover { background: var(--ink-2); }

.btn--outline { background: #fff; color: var(--ink); border-color: var(--line); box-shadow: var(--shadow-sm); }
.btn--outline:hover { border-color: #c9d4e6; }

/* ── Hero ───────────────────────────────────────────────── */
.hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(1100px 520px at 78% -8%, rgba(30, 95, 208, .55), transparent 60%),
    radial-gradient(760px 420px at 8% 8%, rgba(230, 38, 95, .30), transparent 62%),
    radial-gradient(700px 500px at 45% 110%, rgba(245, 158, 11, .20), transparent 60%),
    linear-gradient(165deg, #071429 0%, #0d2246 52%, #123059 100%);
  color: #fff;
  padding: 96px 0 0;
}

/* Chalk-grid texture — nods to the whiteboard without shouting */
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, .05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .05) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(circle at 50% 30%, #000 10%, transparent 72%);
  pointer-events: none;
}

.hero .wrap { position: relative; z-index: 1; }

.hero-grid {
  display: grid;
  grid-template-columns: 1.12fr .88fr;
  gap: 52px;
  align-items: center;
}

.hero h1 { color: #fff; }
.hero h1 .accent {
  background: linear-gradient(100deg, #ff7ba6, #ffc46b);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-sub {
  font-size: 1.19rem;
  color: rgba(233, 240, 252, .82);
  max-width: 30em;
  margin-bottom: 32px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 7px 16px 7px 8px;
  border-radius: 999px;
  background: rgba(255, 255, 255, .09);
  border: 1px solid rgba(255, 255, 255, .18);
  font-size: .87rem;
  font-weight: 600;
  color: rgba(233, 240, 252, .92);
  margin-bottom: 26px;
}
.hero-badge i {
  font-style: normal;
  background: var(--orange);
  color: #3a2500;
  font-weight: 800;
  font-size: .68rem;
  letter-spacing: .07em;
  padding: 3px 9px;
  border-radius: 999px;
  text-transform: uppercase;
}

.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 26px; }

.hero-note { font-size: .89rem; color: rgba(233, 240, 252, .6); margin: 0; }

.hero-visual { position: relative; }
.hero-visual .tablet { transform: perspective(1600px) rotateY(-11deg) rotateX(3deg); }

.hero-strip {
  margin-top: 84px;
  border-top: 1px solid rgba(255, 255, 255, .12);
  background: rgba(4, 12, 26, .34);
}
.hero-strip ul {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 14px 48px;
  list-style: none;
  margin: 0;
  padding: 22px 24px;
}
.hero-strip li {
  display: flex;
  align-items: center;
  gap: 9px;
  color: rgba(233, 240, 252, .8);
  font-size: .93rem;
  font-weight: 600;
}
.hero-strip svg { width: 17px; height: 17px; flex: none; color: #5ce0a0; }

/* ── Device frames ──────────────────────────────────────── */
.tablet {
  background: #0c1220;
  border-radius: 22px;
  padding: 11px;
  box-shadow: var(--shadow-lg), inset 0 0 0 1px rgba(255, 255, 255, .10);
}
.tablet img { border-radius: 12px; width: 100%; }

.phone {
  background: #0c1220;
  border-radius: 34px;
  padding: 8px;
  box-shadow: var(--shadow), inset 0 0 0 1px rgba(255, 255, 255, .09);
}
.phone img { border-radius: 27px; width: 100%; }

/* ── Features ───────────────────────────────────────────── */
.pillars { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }

.pillar {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 32px 28px;
  box-shadow: var(--shadow-sm);
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}
.pillar:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: #d4deee; }

.pillar-icon {
  width: 52px;
  height: 52px;
  border-radius: 15px;
  display: grid;
  place-items: center;
  margin-bottom: 20px;
}
.pillar-icon svg { width: 26px; height: 26px; }
.pillar-icon--pink { background: var(--pink-soft); color: var(--pink); }
.pillar-icon--blue { background: var(--blue-soft); color: var(--blue); }
.pillar-icon--orange { background: var(--orange-soft); color: #c77a00; }

.pillar p { color: var(--muted); margin: 0; font-size: .98rem; }

/* ── Alternating feature rows ───────────────────────────── */
.row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 72px;
  align-items: center;
}
.row + .row { margin-top: 112px; }
.row--flip .row-media { order: 2; }

.row-copy h2 { margin-bottom: .45em; }
.row-copy > p { color: var(--muted); font-size: 1.06rem; }

.checks { list-style: none; margin: 26px 0 0; padding: 0; display: grid; gap: 13px; }
.checks li { display: flex; gap: 12px; align-items: flex-start; font-size: .99rem; }
.checks svg { width: 21px; height: 21px; flex: none; margin-top: 2px; color: var(--green); }
.checks b { font-weight: 700; }

.tag-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 26px; }
.tag {
  font-size: .82rem;
  font-weight: 600;
  padding: 6px 13px;
  border-radius: 999px;
  background: var(--bg-alt);
  border: 1px solid var(--line);
  color: var(--muted);
}
.tag--ink { background: var(--ink); border-color: var(--ink); color: #fff; }

/* Pen-colour swatches */
.swatches { display: flex; align-items: center; gap: 9px; margin-top: 24px; }
.swatch { width: 26px; height: 26px; border-radius: 50%; box-shadow: inset 0 0 0 2px rgba(255, 255, 255, .85), var(--shadow-sm); }
.swatch-label { font-size: .87rem; color: var(--muted); margin-left: 6px; }

/* ── Steps ──────────────────────────────────────────────── */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; counter-reset: step; }
.step { position: relative; padding-top: 20px; }
.step::before {
  counter-increment: step;
  content: counter(step);
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--ink);
  color: #fff;
  font-weight: 800;
  font-size: 1.05rem;
  margin-bottom: 18px;
}
.step h3 { margin-bottom: .35em; }
.step p { color: var(--muted); margin: 0; font-size: .98rem; }

/* ── Screenshot gallery ─────────────────────────────────── */
.shots { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; align-items: start; }
.shot figcaption { margin-top: 16px; text-align: center; font-size: .92rem; color: var(--muted); }
.shot figcaption b { display: block; color: var(--text); font-weight: 700; margin-bottom: 2px; }

/* ── Privacy callout ────────────────────────────────────── */
.privacy-card {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background:
    radial-gradient(760px 400px at 88% 10%, rgba(30, 95, 208, .45), transparent 62%),
    radial-gradient(520px 320px at 4% 90%, rgba(230, 38, 95, .26), transparent 60%),
    linear-gradient(160deg, #081730, #10294f);
  color: #fff;
  padding: 66px 60px;
  box-shadow: var(--shadow-lg);
}
.privacy-card h2 { color: #fff; max-width: 15em; }
.privacy-card > p { color: rgba(233, 240, 252, .8); max-width: 46em; font-size: 1.06rem; }

.privacy-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin: 38px 0 34px;
}
.privacy-item {
  background: rgba(255, 255, 255, .07);
  border: 1px solid rgba(255, 255, 255, .15);
  border-radius: 14px;
  padding: 20px;
}
.privacy-item b { display: block; font-size: 1rem; margin-bottom: 4px; }
.privacy-item span { font-size: .87rem; color: rgba(233, 240, 252, .68); }

/* ── FAQ ────────────────────────────────────────────────── */
.faq { max-width: 780px; margin: 0 auto; }
.faq details {
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fff;
  padding: 4px 22px;
  margin-bottom: 12px;
  box-shadow: var(--shadow-sm);
}
.faq details[open] { border-color: #cfdcf1; }
.faq summary {
  cursor: pointer;
  font-weight: 700;
  padding: 18px 30px 18px 0;
  list-style: none;
  position: relative;
  font-size: 1.02rem;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "";
  position: absolute;
  right: 4px;
  top: 50%;
  width: 9px;
  height: 9px;
  border-right: 2px solid var(--muted);
  border-bottom: 2px solid var(--muted);
  transform: translateY(-65%) rotate(45deg);
  transition: transform .2s ease;
}
.faq details[open] summary::after { transform: translateY(-30%) rotate(-135deg); }
.faq p { color: var(--muted); margin: 0 0 18px; font-size: .98rem; }

/* ── Final CTA ──────────────────────────────────────────── */
.cta { text-align: center; }
.cta img.cta-icon { width: 88px; height: 88px; border-radius: 22px; margin: 0 auto 26px; box-shadow: var(--shadow); }
.cta h2 { margin-bottom: .35em; }
.cta p { color: var(--muted); font-size: 1.1rem; max-width: 34em; margin: 0 auto 32px; }

/* ── Footer ─────────────────────────────────────────────── */
.footer { background: var(--ink); color: rgba(233, 240, 252, .62); padding: 60px 0 34px; font-size: .93rem; }
.footer a { color: rgba(233, 240, 252, .82); }
.footer-top { display: flex; justify-content: space-between; gap: 40px; flex-wrap: wrap; padding-bottom: 34px; border-bottom: 1px solid rgba(255, 255, 255, .1); }
.footer .brand { color: #fff; }
.footer-blurb { max-width: 30em; margin: 14px 0 0; }
.footer-links { display: flex; gap: 44px; }
.footer-links h4 { color: #fff; font-size: .84rem; text-transform: uppercase; letter-spacing: .1em; margin: 0 0 14px; }
.footer-links ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.footer-bottom { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; padding-top: 26px; font-size: .87rem; }

/* ── Legal pages ────────────────────────────────────────── */
.legal-hero {
  background: linear-gradient(165deg, #081730, #12294d);
  color: #fff;
  padding: 76px 0 66px;
}
.legal-hero h1 { color: #fff; font-size: clamp(2rem, 4vw, 2.9rem); margin-bottom: .3em; }
.legal-hero p { color: rgba(233, 240, 252, .86); margin: 0; }
.legal-hero code { background: rgba(255, 255, 255, .1); padding: 2px 7px; border-radius: 6px; font-size: .9em; }

.legal { padding: 72px 0 96px; }
.legal-body { max-width: 760px; margin: 0 auto; }
.legal-body h2 { font-size: 1.5rem; margin: 52px 0 .5em; }
.legal-body h2:first-child { margin-top: 0; }
.legal-body h3 { margin: 30px 0 .4em; }
.legal-body p, .legal-body li { color: #3c4a63; }
.legal-body ul { padding-left: 22px; margin: 0 0 1rem; }
.legal-body li { margin-bottom: 9px; }
.legal-body strong { color: var(--text); }

.callout {
  border-left: 4px solid var(--blue);
  background: var(--blue-soft);
  border-radius: 0 14px 14px 0;
  padding: 20px 24px;
  margin: 0 0 34px;
}
.callout p { margin: 0; color: #204174; }

.summary-table { width: 100%; border-collapse: collapse; margin: 0 0 1rem; font-size: .95rem; }
.summary-table th, .summary-table td { text-align: left; padding: 13px 14px; border-bottom: 1px solid var(--line); vertical-align: top; }
.summary-table th { font-weight: 700; color: var(--ink); background: var(--bg-alt); }
.table-scroll { overflow-x: auto; }

.toc { background: var(--bg-alt); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px 30px; margin-bottom: 44px; }
.toc h2 { font-size: .84rem !important; text-transform: uppercase; letter-spacing: .1em; color: var(--muted); margin: 0 0 14px !important; }
.toc ol { margin: 0; padding-left: 20px; columns: 2; column-gap: 32px; }
.toc li { margin-bottom: 7px; }

/* ── Responsive ─────────────────────────────────────────── */
@media (max-width: 980px) {
  .section { padding: 72px 0; }
  .hero { padding-top: 64px; }
  .hero-grid { grid-template-columns: 1fr; gap: 48px; }
  .hero-visual .tablet { transform: none; }
  .hero-strip { margin-top: 56px; }
  .row, .row + .row { grid-template-columns: 1fr; gap: 40px; }
  .row + .row { margin-top: 80px; }
  .row--flip .row-media { order: 0; }
  .pillars, .steps, .shots { grid-template-columns: 1fr; }
  .privacy-grid { grid-template-columns: repeat(2, 1fr); }
  .privacy-card { padding: 46px 30px; }
  .nav-links { display: none; }
  .toc ol { columns: 1; }
}

@media (max-width: 560px) {
  .wrap { padding: 0 18px; }
  .privacy-grid { grid-template-columns: 1fr; }
  .hero-cta .btn { width: 100%; }
  .footer-links { gap: 32px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; animation: none !important; }
}