:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --text: #1f2933;
  --muted: #5b6b7b;
  --line: #cfd6de;
  --accent: #1f5fa8;
  --accent-dark: #174a84;
  --error: #b42318;
  --error-bg: #fdecea;
  --ok: #1d7a46;
  --ok-bg: #e7f6ed;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 1.05rem;
  line-height: 1.5;
  color: var(--text);
  background: var(--bg);
}

header, main, footer {
  max-width: 44rem;
  margin: 0 auto;
  padding: 0 1rem;
}

header { padding-top: 2rem; }
header .school { margin: 0; color: var(--muted); font-weight: 600; letter-spacing: .02em; }
header h1 { margin: .25rem 0 1rem; font-size: 1.8rem; line-height: 1.2; }

main {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: .75rem;
  padding: 1.5rem 1.25rem 2rem;
}

.intro { margin-top: 0; }

fieldset {
  border: 0;
  padding: 0;
  margin: 1.75rem 0 0;
}

legend {
  font-size: 1.15rem;
  font-weight: 700;
  padding: 0;
  margin-bottom: .75rem;
}

.field { margin-bottom: 1rem; }
.row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
@media (max-width: 30rem) { .row { grid-template-columns: 1fr; } }

label { display: block; font-weight: 600; margin-bottom: .3rem; }
.optional { font-weight: 400; color: var(--muted); }

input[type="text"], input[type="email"], input[type="date"], select {
  width: 100%;
  font: inherit;
  padding: .55rem .7rem;
  border: 1px solid var(--line);
  border-radius: .4rem;
  background: #fff;
  color: var(--text);
}

input:focus, select:focus, button:focus, summary:focus {
  outline: 3px solid rgba(31, 95, 168, .35);
  outline-offset: 1px;
}

.invalid input, .invalid select { border-color: var(--error); }

.hint { margin: .35rem 0 0; font-size: .92rem; color: var(--muted); }
.error { margin: .35rem 0 0; font-size: .95rem; color: var(--error); font-weight: 600; }

.alert {
  background: var(--error-bg);
  border: 1px solid var(--error);
  border-radius: .5rem;
  padding: .75rem 1rem;
  margin-bottom: 1rem;
}

.checkbox { display: grid; grid-template-columns: auto 1fr; gap: .6rem; align-items: start; }
.checkbox input { margin-top: .35rem; width: 1.15rem; height: 1.15rem; }
.checkbox label { font-weight: 400; margin: 0; }
.checkbox .error { grid-column: 2; }

details.privacy {
  border: 1px solid var(--line);
  border-radius: .5rem;
  padding: .5rem .9rem;
  margin-bottom: 1rem;
}
details.privacy summary { cursor: pointer; font-weight: 600; }
.privacy-text { font-size: .95rem; color: var(--text); }
.privacy-text h3 { font-size: 1rem; margin: 1rem 0 .25rem; }

.hp { position: absolute; left: -10000px; top: auto; width: 1px; height: 1px; overflow: hidden; }

.submit { margin-top: 1.75rem; }

button[type="submit"] {
  font: inherit;
  font-weight: 700;
  color: #fff;
  background: var(--accent);
  border: 0;
  border-radius: .5rem;
  padding: .75rem 1.5rem;
  cursor: pointer;
}
button[type="submit"]:hover { background: var(--accent-dark); }
button[type="submit"]:disabled { background: #9aa8b6; cursor: not-allowed; }

.captcha { margin: .75rem 0 0; font-size: .95rem; color: var(--muted); }
.captcha.ok { color: var(--ok); }
.captcha.invalid { color: var(--error); font-weight: 600; }

.success {
  background: var(--ok-bg);
  border: 1px solid var(--ok);
  border-radius: .5rem;
  padding: 1rem 1.25rem;
}
.success h2 { margin-top: 0; }

footer { padding: 1.5rem 1rem 2.5rem; color: var(--muted); font-size: .92rem; }
footer a { color: inherit; }

header .event { margin: .1rem 0 0; color: var(--muted); }
ul.forms { list-style: none; padding: 0; margin: 0; }
ul.forms li { border: 1px solid var(--line); border-radius: .5rem; padding: 1rem 1.25rem; margin-bottom: 1rem; }
ul.forms a { font-size: 1.15rem; font-weight: 700; color: var(--accent); }
ul.forms p { margin: .35rem 0 0; color: var(--muted); }