/* Simply Maths UK - notebook look, same palette as the YouTube channel */
@font-face {
  font-family: "Caveat";
  src: url("/assets/caveat-700.woff2") format("woff2");
  font-weight: 700;
  font-display: swap;
}

:root {
  --navy: #0f1b3d;
  --yellow: #f6b829;
  --red-line: #e8a0a0;
  --blue-line: #dbe4f5;
  --paper: #fdfcf7;
  --ink: #1d2433;
  --muted: #5a6275;
  --card: #ffffff;
  --border: #e3e6ee;
  --link: #1f4fbf;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #10162b;
    --ink: #e9ecf4;
    --muted: #a7afc3;
    --card: #182143;
    --border: #2a3560;
    --blue-line: #1a2448;
    --red-line: #5a2f3d;
    --link: #8fb1ff;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    linear-gradient(to right, transparent 46px, var(--red-line) 46px, var(--red-line) 48px, transparent 48px),
    repeating-linear-gradient(to bottom, transparent 0, transparent 31px, var(--blue-line) 31px, var(--blue-line) 32px);
  font: 17px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

.wrap { max-width: 860px; margin: 0 auto; padding: 0 20px 0 64px; }

a { color: var(--link); }
a:focus-visible, .btn:focus-visible { outline: 3px solid var(--yellow); outline-offset: 2px; }

header.site {
  display: flex; align-items: center; gap: 14px;
  padding: 22px 0 6px;
}
header.site img { width: 56px; height: 56px; border-radius: 50%; }
header.site a.brand { text-decoration: none; color: var(--ink); font-family: "Caveat", cursive; font-size: 32px; line-height: 1; }
header.site nav { margin-left: auto; display: flex; gap: 16px; font-size: 15px; }

h1, h2, h3 { font-family: "Caveat", cursive; font-weight: 700; line-height: 1.15; margin: 0.6em 0 0.3em; }
h1 { font-size: clamp(44px, 8vw, 68px); }
h2 { font-size: 36px; }
h3 { font-size: 30px; margin-top: 0; }

.hero { padding: 28px 0 8px; }
.hero .logo { width: 140px; height: 140px; border-radius: 50%; display: block; }
.hero p.lead { font-size: 20px; max-width: 34em; }
.underline { background: linear-gradient(transparent 62%, var(--yellow) 62%); }

.cards { display: grid; gap: 18px; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); margin: 26px 0; }
.card {
  background: var(--card); border: 1px solid var(--border); border-radius: 14px;
  padding: 20px; display: flex; flex-direction: column;
}
.card p { margin: 0 0 16px; flex: 1; }
.tag { display: inline-block; font-size: 13px; font-weight: 600; letter-spacing: .02em; color: var(--navy);
  background: var(--yellow); border-radius: 999px; padding: 2px 10px; margin-bottom: 10px; align-self: flex-start; }

.btn {
  display: inline-block; align-self: flex-start; text-decoration: none; font-weight: 600;
  background: var(--navy); color: #fff; border-radius: 10px; padding: 10px 16px;
}
@media (prefers-color-scheme: dark) { .btn { background: var(--yellow); color: var(--navy); } }
.btn.muted { background: transparent; color: var(--muted); border: 1px dashed var(--border); }

.follow { display: flex; flex-wrap: wrap; gap: 10px 18px; padding: 0; list-style: none; }

.note { color: var(--muted); font-size: 15px; }

main.doc { max-width: 42em; padding-bottom: 20px; }
main.doc h2 { font-size: 32px; }

footer.site {
  border-top: 1px solid var(--border); margin-top: 40px; padding: 18px 0 30px;
  font-size: 14px; color: var(--muted);
}
footer.site a { color: var(--muted); }
footer.site .links { display: flex; flex-wrap: wrap; gap: 6px 16px; margin-bottom: 6px; }

@media (max-width: 560px) {
  body { background-image:
    linear-gradient(to right, transparent 22px, var(--red-line) 22px, var(--red-line) 23px, transparent 23px),
    repeating-linear-gradient(to bottom, transparent 0, transparent 31px, var(--blue-line) 31px, var(--blue-line) 32px); }
  .wrap { padding: 0 16px 0 36px; }
  header.site nav { display: none; }
  .hero .logo { width: 110px; height: 110px; }
}