:root {
  color-scheme: light;
  --theme: oklch(56% 0.16 215);
  --primary: var(--theme);
  --background: oklch(from var(--theme) 0.98 calc(c * 0.03) h);
  --surface: oklch(from var(--theme) 1 0 h);
  --text: oklch(from var(--theme) 0.31 calc(c * 0.25) h);
  --muted: oklch(from var(--theme) 0.54 calc(c * 0.24) h);
  --border: oklch(from var(--theme) 0.91 calc(c * 0.1) h);
  --stripe: oklch(from var(--theme) 0.985 calc(c * 0.03) h);
  --hover: oklch(from var(--theme) 0.96 calc(c * 0.1) h);
  --accent: oklch(from var(--theme) 0.51 c h);
  --selected: oklch(from var(--theme) 0.95 calc(c * 0.15) h);
  --on-primary: oklch(from var(--theme) 1 0 h);
  --shadow: 0 0.125rem 0.5rem oklch(from var(--theme) 0.3 calc(c * 0.4) h / 5%);
}

body[data-theme="dark"] {
  color-scheme: dark;
  --background: oklch(from var(--theme) 0.18 calc(c * 0.03) h);
  --surface: oklch(from var(--theme) 0.23 calc(c * 0.04) h);
  --text: oklch(from var(--theme) 0.95 calc(c * 0.06) h);
  --muted: oklch(from var(--theme) 0.76 calc(c * 0.16) h);
  --border: oklch(from var(--theme) 0.35 calc(c * 0.1) h);
  --stripe: oklch(from var(--theme) 0.26 calc(c * 0.06) h);
  --hover: oklch(from var(--theme) 0.32 calc(c * 0.2) h);
  --accent: oklch(from var(--theme) 0.8 calc(c * 0.65) h);
  --selected: oklch(from var(--theme) 0.35 calc(c * 0.35) h);
  --shadow: none;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-width: 20rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--background);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  font-size: 0.9375rem;
  line-height: 1.5;
}

button { font: inherit; cursor: pointer; }
button:disabled { opacity: .5; cursor: not-allowed; }

:focus-visible {
  outline: 0.1875rem solid var(--accent);
  outline-offset: 0.25rem;
}

.site-header {
  background: var(--primary);
  color: var(--on-primary);
  box-shadow: 0 0.125rem 0.375rem oklch(from var(--theme) 0 0 h / 15%);
}

.header-content {
  max-width: 70rem;
  margin: auto;
  padding: 0.875rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand { display: flex; align-items: center; gap: 0.875rem; }
.brand img { width: 2.5rem; height: 2.5rem; object-fit: contain; }
h1 { margin: 0; font-size: 1.4375rem; font-weight: 600; letter-spacing: -0.03125rem; }

.theme-toggle {
  display: grid;
  place-items: center;
  width: 2.75rem;
  height: 2.75rem;
  flex-shrink: 0;
  border: 0;
  border-radius: 50%;
  background: oklch(0% 0 0 / 0%);
  color: inherit;
}

.theme-toggle:hover { background: oklch(from var(--theme) 1 0 h / 15%); }
.theme-toggle:focus-visible { outline-color: var(--on-primary); }

.theme-icon {
  font-size: 1.5rem;
  line-height: 1;
}

.icon-sun { display: none; }
body[data-theme="dark"] .icon-sun { display: block; }
body[data-theme="dark"] .icon-moon { display: none; }

main {
  width: min(100%, 70rem);
  margin: 0 auto;
  padding: 2.25rem 1.5rem 3rem;
  flex: 1;
}

.class-picker { margin-bottom: 2.125rem; }
.action { display: flex; flex-wrap: wrap; gap: 0.625rem; }

.btn-schedule {
  min-height: 2.75rem;
  padding: 0.625rem 1.375rem;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  background: var(--surface);
  color: var(--text);
  font-weight: 500;
}

.btn-schedule:hover { border-color: var(--accent); background: var(--hover); }
.btn-schedule.selected { background: var(--selected); border-color: var(--accent); color: var(--accent); }

#schedule-status { margin: 0 0 1rem; color: var(--muted); font-size: 0.875rem; }
#schedule-status:empty { display: none; }

.table-scroll {
  overflow-x: auto;
  scrollbar-color: var(--border) var(--surface);
  scrollbar-width: thin;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  background: var(--surface);
  box-shadow: var(--shadow);
}

table { width: 100%; border-collapse: collapse; text-align: left; }
td { padding: 0.75rem 1.25rem; vertical-align: middle; }
tbody tr + tr td { border-top: 1px solid var(--border); }
tbody tr:nth-child(even) { background: var(--stripe); }
tbody tr:hover { background: var(--hover); }
.date, .hours, .room { white-space: nowrap; font-variant-numeric: tabular-nums; }
.date, .hours, .room { width: 1%; }
.hours { color: var(--muted); font-size: 0.8125rem; line-height: 1.3; }
.hours span { display: block; }
.course { font-weight: 500; }
.room { color: var(--accent); }

.site-footer {
  padding: 1.125rem 1.5rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  text-align: center;
  font-size: 0.75rem;
}

@media (max-width: 37.5rem) {
  .header-content { padding: 0.75rem 1rem; }
  h1 { font-size: 1.25rem; }
  main { padding: 1.75rem 1rem 2.25rem; }
  .action { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0.5rem; }
  .btn-schedule { padding: 0.625rem 0.5rem; }
  td { padding: 0.625rem; }
}