:root {
  --teal: #0f766e;
  --teal-dark: #115e59;
  --teal-soft: #ccfbf1;
  --ink: #12302d;
  --muted: #55706c;
  --bg: #f6fbfa;
  --card: #ffffff;
  --line: #d7e8e5;
  --warn: #b45309;
  --warn-bg: #fef3c7;
  --red: #b91c1c;
  --radius: 14px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, Roboto, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
}
a { color: var(--teal-dark); }
.wrap { width: min(1100px, 92%); margin: 0 auto; }
.narrow { max-width: 640px; }
.section { padding: 56px 0; }
.band { background: #eaf6f4; }
h1, h2, h3 { line-height: 1.2; margin: 0 0 12px; }
h2 { font-size: 1.9rem; }
.muted { color: var(--muted); }
.small { font-size: .88rem; }

/* header */
.site-header {
  position: sticky; top: 0; z-index: 10;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--line);
}
.nav { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 12px 0; flex-wrap: wrap; }
.brand { font-weight: 800; font-size: 1.25rem; text-decoration: none; color: var(--teal-dark); }
.brand span { color: #e11d48; }
.nav nav { display: flex; gap: 6px; flex-wrap: wrap; }
.nav nav a { text-decoration: none; color: var(--ink); padding: 6px 12px; border-radius: 999px; font-size: .95rem; }
.nav nav a:hover { background: var(--teal-soft); }

/* hero */
.hero {
  background: linear-gradient(135deg, #0f766e 0%, #0e9488 55%, #14b8a6 100%);
  color: #fff;
  padding: 90px 0 80px;
}
.eyebrow { text-transform: uppercase; letter-spacing: .12em; font-size: .8rem; opacity: .9; margin: 0 0 10px; }
.hero h1 { font-size: clamp(2.2rem, 6vw, 3.8rem); }
.lead { font-size: 1.2rem; max-width: 640px; opacity: .96; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 24px; }

.btn {
  display: inline-block; border: 2px solid #fff; background: #fff; color: var(--teal-dark);
  padding: 11px 22px; border-radius: 999px; font-weight: 700; font-size: 1rem;
  text-decoration: none; cursor: pointer; transition: transform .15s, box-shadow .15s;
}
.btn:hover { transform: translateY(-2px); box-shadow: 0 6px 16px rgba(0,0,0,.15); }
.btn.ghost { background: transparent; color: #fff; }
.band .btn, .quiz .btn, form .btn { background: var(--teal); border-color: var(--teal); color: #fff; }

/* cards */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 18px; margin-top: 20px; }
.cards.three { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 20px; box-shadow: 0 2px 8px rgba(15,118,110,.06);
}
.card h3 { font-size: 1.1rem; }
.card p { margin: 6px 0; }
.card .meta { font-size: .92rem; margin: 2px 0; }
.icon { font-size: 2rem; margin-bottom: 6px; }
.item.hidden { display: none; }

.tag { display: inline-block; font-size: .75rem; font-weight: 700; padding: 3px 10px; border-radius: 999px; margin-bottom: 8px; text-transform: uppercase; letter-spacing: .04em; }
.tag-req { background: #fee2e2; color: var(--red); }
.tag-rec { background: var(--teal-soft); color: var(--teal-dark); }

/* filters */
.filters { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
.chip {
  border: 1px solid var(--teal); background: #fff; color: var(--teal-dark);
  padding: 7px 14px; border-radius: 999px; cursor: pointer; font-size: .92rem; font-family: inherit;
}
.chip:hover { background: var(--teal-soft); }
.chip.active { background: var(--teal); color: #fff; }

/* myths */
.myths { display: grid; gap: 12px; margin-top: 18px; }
.myth { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 14px 18px; }
.myth summary { cursor: pointer; font-weight: 700; list-style: none; }
.myth summary::-webkit-details-marker { display: none; }
.myth .x { color: var(--red); font-weight: 800; margin-right: 6px; }
.myth .ok { color: var(--teal); font-weight: 800; margin-right: 6px; }
.myth p { margin: 10px 0 0; }

/* quiz */
.quiz { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; margin-top: 18px; }
.quiz .progress { height: 8px; background: var(--teal-soft); border-radius: 99px; overflow: hidden; margin-bottom: 16px; }
.quiz .progress span { display: block; height: 100%; background: var(--teal); transition: width .3s; }
.quiz h3 { font-size: 1.25rem; }
.options { display: grid; gap: 10px; margin: 14px 0; }
.option {
  text-align: left; padding: 12px 16px; border-radius: 10px; border: 2px solid var(--line);
  background: #fff; font-size: 1rem; cursor: pointer; font-family: inherit; color: var(--ink);
}
.option:hover:not(:disabled) { border-color: var(--teal); }
.option.correct { border-color: #15803d; background: #dcfce7; }
.option.wrong { border-color: var(--red); background: #fee2e2; }
.explain { background: var(--teal-soft); border-radius: 10px; padding: 10px 14px; margin: 10px 0; }
.result { text-align: center; }
.result .big { font-size: 3rem; font-weight: 800; color: var(--teal); }

/* form */
form { display: grid; gap: 14px; margin-top: 16px; }
label { display: grid; gap: 6px; font-weight: 600; }
input[type=text], textarea {
  font: inherit; padding: 10px 12px; border: 1px solid var(--line); border-radius: 10px; background: #fff;
}
input:focus, textarea:focus, button:focus-visible, a:focus-visible, summary:focus-visible {
  outline: 3px solid #5eead4; outline-offset: 2px;
}
.hp { position: absolute; left: -9999px; }
.form-msg { margin: 0; font-weight: 600; }
.form-msg.ok { color: #15803d; }
.form-msg.err { color: var(--red); }

.alert { background: var(--warn-bg); color: var(--warn); border-radius: 10px; padding: 14px 18px; margin-top: 20px; font-weight: 600; }

.site-footer { background: #0b3b37; color: #d7f2ee; padding: 28px 0; font-size: .92rem; }
.site-footer a { color: #99f6e4; }

@media (max-width: 600px) {
  .section { padding: 40px 0; }
  .hero { padding: 60px 0 50px; }
}