:root {
  color-scheme: light;
  font-family: "Sarabun", "Noto Sans Thai", system-ui, sans-serif;
  color: #18253a;
  background: #f3f5f8;
  --navy: #123052;
  --navy-dark: #0b2038;
  --gold: #b59145;
  --line: #dce2e9;
}

* {
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  margin: 0;
  display: flex;
  flex-direction: column;
}

a {
  color: inherit;
}

.shell {
  width: min(1120px, calc(100% - 32px));
  margin-inline: auto;
}

.site-header {
  color: #fff;
  background: var(--navy);
  border-bottom: 4px solid var(--gold);
}

.header-inner {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-mark {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border: 1px solid rgb(255 255 255 / 45%);
  border-radius: 50%;
  color: var(--navy-dark);
  background: #fff;
  font-family: Georgia, serif;
  font-size: 26px;
  font-weight: 700;
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  letter-spacing: 0.08em;
}

.brand small {
  margin-top: 2px;
  color: #d9e3ee;
  font-size: 11px;
}

.admin-link {
  padding: 9px 12px;
  border: 1px solid rgb(255 255 255 / 35%);
  border-radius: 6px;
  font-size: 14px;
  text-decoration: none;
}

.admin-link:hover,
.admin-link:focus-visible {
  background: rgb(255 255 255 / 10%);
}

.page {
  flex: 1;
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(320px, 440px);
  align-items: center;
  gap: clamp(40px, 8vw, 100px);
  padding-block: 72px;
}

.eyebrow,
.step {
  margin: 0 0 10px;
  color: #806322;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.intro h1 {
  max-width: 720px;
  margin: 0;
  color: var(--navy-dark);
  font-size: clamp(34px, 5vw, 56px);
  line-height: 1.2;
}

.intro > p:not(.eyebrow) {
  max-width: 650px;
  margin: 24px 0 0;
  color: #56657a;
  font-size: 18px;
  line-height: 1.8;
}

.school-name {
  margin-top: 30px;
  padding-left: 14px;
  border-left: 3px solid var(--gold);
  color: var(--navy);
  font-weight: 700;
}

.login-card {
  padding: clamp(28px, 5vw, 42px);
  border: 1px solid var(--line);
  border-top: 4px solid var(--gold);
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 18px 45px rgb(18 48 82 / 10%);
}

.card-heading h2 {
  margin: 0;
  color: var(--navy-dark);
  font-size: 30px;
}

.card-heading > p:last-child,
.help {
  color: #68768a;
  line-height: 1.6;
}

form {
  margin-top: 28px;
}

label {
  display: block;
  margin-bottom: 8px;
  color: #263951;
  font-size: 14px;
  font-weight: 700;
}

input {
  width: 100%;
  min-height: 48px;
  padding: 10px 13px;
  border: 1px solid #b8c2ce;
  border-radius: 6px;
  color: #17283d;
  background: #fff;
  font: inherit;
}

input:focus {
  border-color: var(--navy);
  outline: 3px solid rgb(18 48 82 / 15%);
}

button {
  width: 100%;
  min-height: 48px;
  margin-top: 16px;
  border: 0;
  border-radius: 6px;
  color: #fff;
  background: var(--navy);
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

button:hover,
button:focus-visible {
  background: var(--navy-dark);
}

.help {
  margin: 22px 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-size: 13px;
}

footer {
  padding-block: 20px;
  color: #697587;
  border-top: 1px solid var(--line);
  background: #fff;
  font-size: 13px;
  text-align: center;
}

@media (max-width: 760px) {
  .header-inner {
    min-height: 68px;
  }

  .brand small {
    display: none;
  }

  .page {
    grid-template-columns: 1fr;
    gap: 34px;
    padding-block: 42px;
  }

  .intro h1 {
    font-size: 34px;
  }

  .intro > p:not(.eyebrow) {
    font-size: 16px;
  }
}