:root {
  color: #12303a;
  background: #edf5f4;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  margin: 0;
  background:
    radial-gradient(circle at top right, rgb(82 188 176 / 22%), transparent 34rem),
    #edf5f4;
}

.site-header,
main,
footer {
  width: min(68rem, calc(100% - 2rem));
  margin-inline: auto;
}

.site-header {
  padding: 4rem 0 2rem;
}

.eyebrow,
.card-label {
  margin: 0 0 0.5rem;
  color: #17695f;
  font-size: 0.78rem;
  font-weight: 750;
  letter-spacing: 0.11em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  max-width: 18ch;
  margin: 0;
  font-size: clamp(2.3rem, 7vw, 4.8rem);
  line-height: 0.98;
  letter-spacing: -0.045em;
}

.intro {
  max-width: 42rem;
  margin: 1.25rem 0 0;
  color: #46626a;
  font-size: 1.05rem;
}

.selector-panel,
.schedule {
  border: 1px solid rgb(23 105 95 / 20%);
  border-radius: 1.25rem;
  background: rgb(255 255 255 / 82%);
  box-shadow: 0 1.2rem 3.5rem rgb(18 48 58 / 10%);
}

.selector-panel {
  padding: 1.4rem;
}

.selector-panel label {
  display: block;
  margin-bottom: 0.55rem;
  font-weight: 700;
}

.selector-row {
  display: flex;
  gap: 0.75rem;
}

input,
button {
  min-height: 3rem;
  border-radius: 0.75rem;
  font: inherit;
}

input {
  min-width: 0;
  flex: 1;
  border: 1px solid #9db7b4;
  padding: 0 0.9rem;
  color: inherit;
  background: #fff;
}

input:focus-visible,
button:focus-visible {
  outline: 3px solid #ffbf47;
  outline-offset: 2px;
}

button {
  border: 0;
  padding: 0 1.2rem;
  color: #fff;
  background: #17695f;
  font-weight: 750;
  cursor: pointer;
}

button:hover {
  background: #0f5149;
}

.hint,
.generated-at,
footer {
  color: #5a7177;
  font-size: 0.88rem;
}

.hint {
  margin: 0.7rem 0 0;
}

.request-status {
  min-height: 1.5rem;
  margin: 1rem 0;
  color: #36565d;
}

.schedule {
  padding: clamp(1.2rem, 4vw, 2rem);
}

.schedule-heading-row {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 1rem;
}

h2 {
  margin: 0;
  font-size: 2rem;
}

.generated-at {
  margin: 0;
  text-align: right;
}

.day-state {
  margin: 0.8rem 0 1.5rem;
  color: #36565d;
}

.lesson-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.lesson-card {
  border: 1px solid #c8d9d6;
  border-radius: 1rem;
  padding: 1.25rem;
  background: #f8fbfa;
}

.lesson-card-current {
  border-color: #4a9f94;
  background: #e4f4f1;
}

.lesson-card h3 {
  min-height: 2.4rem;
  margin: 0 0 1rem;
  font-size: 1.45rem;
}

dl {
  display: grid;
  gap: 0.7rem;
  margin: 0;
}

dl div {
  display: grid;
  grid-template-columns: 5rem minmax(0, 1fr);
  gap: 0.6rem;
}

dt {
  color: #5a7177;
}

dd {
  margin: 0;
  font-weight: 650;
}

footer {
  padding: 2rem 0;
  text-align: center;
}

[hidden] {
  display: none !important;
}

@media (max-width: 42rem) {
  .site-header {
    padding-top: 2.5rem;
  }

  .selector-row,
  .schedule-heading-row {
    align-items: stretch;
    flex-direction: column;
  }

  .generated-at {
    text-align: left;
  }

  .lesson-grid {
    grid-template-columns: 1fr;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    color: #e8f5f2;
    background: #0e252c;
  }

  body {
    background:
      radial-gradient(circle at top right, rgb(82 188 176 / 16%), transparent 34rem),
      #0e252c;
  }

  .intro,
  .request-status,
  .day-state,
  .hint,
  .generated-at,
  footer,
  dt {
    color: #adc3c3;
  }

  .selector-panel,
  .schedule {
    border-color: rgb(138 203 194 / 22%);
    background: rgb(17 48 57 / 92%);
  }

  input {
    border-color: #52736f;
    color: #e8f5f2;
    background: #18363f;
  }

  .lesson-card {
    border-color: #3b5b5b;
    background: #15333b;
  }

  .lesson-card-current {
    border-color: #4a9f94;
    background: #17443f;
  }
}