:root {
  --colorNeutralBackground1: #ffffff;
  --colorNeutralBackground2: #fafafa;
  --colorNeutralBackground3: #f5f5f5;
  --colorNeutralBackground1Hover: #f5f5f5;
  --colorNeutralBackgroundCanvas: #f0f0f0;
  --colorNeutralForeground1: #242424;
  --colorNeutralForeground2: #424242;
  --colorNeutralForeground3: #616161;
  --colorNeutralForegroundOnBrand: #ffffff;
  --colorNeutralStroke1: #d1d1d1;
  --colorNeutralStroke2: #e0e0e0;
  --colorBrandBackground: #0f6cbd;
  --colorBrandBackgroundHover: #115ea3;
  --colorBrandForeground: #0f6cbd;
  --colorPaletteGreenForeground: #0e700e;
  --colorPaletteGreenBackground: #e7f7e7;
  --colorPaletteRedForeground: #b10e1c;
  --colorPaletteRedBackground: #fdf3f4;
  --colorPaletteYellowForeground: #835b00;
  --colorPaletteYellowBackground: #fff4ce;
  --shadow4: 0 0 2px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.14);
  --radiusM: 6px;
  --radiusL: 8px;
  --fontFamilyBase: "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif;
  --fontFamilyMono: "Cascadia Code", "Cascadia Mono", Consolas, "Courier New", monospace;
  --headerHeight: 56px;
  --railWidth: 228px;
}

[data-theme="dark"] {
  --colorNeutralBackground1: #292929;
  --colorNeutralBackground2: #1f1f1f;
  --colorNeutralBackground3: #141414;
  --colorNeutralBackground1Hover: #383838;
  --colorNeutralBackgroundCanvas: #0f0f0f;
  --colorNeutralForeground1: #ffffff;
  --colorNeutralForeground2: #d6d6d6;
  --colorNeutralForeground3: #adadad;
  --colorNeutralStroke1: #666666;
  --colorNeutralStroke2: #3d3d3d;
  --colorBrandBackground: #115ea3;
  --colorBrandBackgroundHover: #0f6cbd;
  --colorBrandForeground: #479ef5;
  --colorPaletteGreenForeground: #54b054;
  --colorPaletteGreenBackground: #052505;
  --colorPaletteRedForeground: #e37d80;
  --colorPaletteRedBackground: #3b1b1d;
  --colorPaletteYellowForeground: #e6c14b;
  --colorPaletteYellowBackground: #3a2f0b;
  --shadow4: 0 0 2px rgba(0,0,0,0.4), 0 1px 2px rgba(0,0,0,0.5);
}

* { box-sizing: border-box; }

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: var(--fontFamilyBase);
  background-color: var(--colorNeutralBackgroundCanvas);
  color: var(--colorNeutralForeground1);
  font-size: 14px;
  line-height: 1.4;
  -webkit-font-smoothing: antialiased;
}

button,
select {
  font: inherit;
}

.appbar {
  position: sticky;
  top: 0;
  z-index: 10;
  height: var(--headerHeight);
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 0 16px;
  background-color: var(--colorNeutralBackground1);
  border-bottom: 1px solid var(--colorNeutralStroke2);
  box-shadow: var(--shadow4);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  width: 32px;
  height: 32px;
  border-radius: var(--radiusM);
  background-color: var(--colorBrandBackground);
  color: var(--colorNeutralForegroundOnBrand);
  display: grid;
  place-items: center;
  font-weight: 700;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.brand-text span,
.page-desc {
  color: var(--colorNeutralForeground3);
  font-size: 12px;
}

.appbar-spacer { flex: 1; }

.layout {
  display: grid;
  grid-template-columns: var(--railWidth) minmax(0, 1fr);
  min-height: calc(100vh - var(--headerHeight));
}

.rail {
  position: sticky;
  top: var(--headerHeight);
  height: calc(100vh - var(--headerHeight));
  padding: 12px;
  background-color: var(--colorNeutralBackground1);
  border-right: 1px solid var(--colorNeutralStroke2);
}

.nav-item {
  width: 100%;
  min-height: 38px;
  border: 0;
  border-radius: var(--radiusM);
  display: flex;
  align-items: center;
  padding: 0 12px;
  margin-bottom: 4px;
  color: var(--colorNeutralForeground2);
  background: transparent;
  cursor: pointer;
  text-align: left;
}

.nav-item:hover,
.nav-item.active {
  background-color: var(--colorNeutralBackground1Hover);
  color: var(--colorBrandForeground);
}

.content {
  width: min(1440px, 100%);
  padding: 24px;
}

.view { display: none; }
.view.active { display: block; }

.page-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
}

.page-title {
  margin: 0 0 4px;
  font-size: 28px;
  letter-spacing: 0;
}

.toolbar {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.btn,
.select {
  min-height: 34px;
  border: 1px solid var(--colorNeutralStroke1);
  border-radius: var(--radiusM);
  background-color: var(--colorNeutralBackground1);
  color: var(--colorNeutralForeground1);
  padding: 0 12px;
}

.btn {
  cursor: pointer;
}

.btn:hover {
  background-color: var(--colorNeutralBackground1Hover);
}

.btn.primary {
  border-color: var(--colorBrandBackground);
  background-color: var(--colorBrandBackground);
  color: var(--colorNeutralForegroundOnBrand);
}

.btn.primary:hover {
  background-color: var(--colorBrandBackgroundHover);
}

.btn.small {
  min-height: 28px;
  padding: 0 8px;
  font-size: 12px;
}

.alert {
  margin-bottom: 16px;
  padding: 10px 12px;
  border: 1px solid var(--colorPaletteGreenForeground);
  border-radius: var(--radiusM);
  color: var(--colorPaletteGreenForeground);
  background-color: var(--colorPaletteGreenBackground);
}

.alert.danger {
  color: var(--colorPaletteRedForeground);
  background-color: var(--colorPaletteRedBackground);
  border-color: var(--colorPaletteRedForeground);
}

.hidden { display: none; }

.metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 16px;
}

.metric,
.card {
  background-color: var(--colorNeutralBackground1);
  border: 1px solid var(--colorNeutralStroke2);
  border-radius: var(--radiusL);
  box-shadow: var(--shadow4);
}

.metric {
  min-height: 108px;
  padding: 14px;
  display: grid;
  align-content: space-between;
}

.metric-label,
.metric-foot,
.lesson-meta,
.status-line,
.kv span {
  color: var(--colorNeutralForeground3);
  font-size: 12px;
}

.metric-value {
  font-size: 22px;
  font-weight: 650;
  overflow-wrap: anywhere;
}

.grid {
  display: grid;
  gap: 16px;
  margin-bottom: 16px;
}

.grid.two {
  grid-template-columns: minmax(0, 1.2fr) minmax(320px, 0.8fr);
}

.card {
  padding: 16px;
  margin-bottom: 16px;
}

.card-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.card-title {
  margin: 0 0 4px;
  font-size: 18px;
}

.kv {
  display: grid;
  grid-template-columns: 110px minmax(0, 1fr);
  gap: 10px 12px;
}

.kv strong {
  overflow-wrap: anywhere;
}

.date-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(176px, 1fr));
  gap: 8px;
}

.date-chip {
  min-height: 86px;
  border: 1px solid var(--colorNeutralStroke2);
  border-radius: var(--radiusM);
  background-color: var(--colorNeutralBackground1);
  color: var(--colorNeutralForeground1);
  padding: 10px;
  text-align: left;
  cursor: pointer;
}

.date-chip:hover,
.date-chip.active {
  border-color: var(--colorBrandBackground);
  box-shadow: 0 0 0 1px var(--colorBrandBackground);
}

.date-chip strong,
.date-chip span,
.date-chip small {
  display: block;
}

.date-chip span {
  margin-top: 4px;
}

.date-chip small {
  margin-top: 6px;
  color: var(--colorNeutralForeground3);
}

.lesson-list {
  display: grid;
  gap: 10px;
}

.lesson-list.compact {
  max-height: 480px;
  overflow: auto;
}

.lesson {
  display: grid;
  grid-template-columns: 116px minmax(0, 1fr) auto;
  gap: 12px;
  align-items: start;
  min-height: 86px;
  padding: 12px;
  border: 1px solid var(--colorNeutralStroke2);
  border-left: 4px solid var(--colorBrandBackground);
  border-radius: var(--radiusM);
  background-color: var(--colorNeutralBackground2);
}

.lesson.cancelled { border-left-color: var(--colorPaletteRedForeground); }
.lesson.changed { border-left-color: var(--colorPaletteYellowForeground); }
.lesson.exam { border-left-color: var(--colorPaletteGreenForeground); }

.lesson-time {
  font-family: var(--fontFamilyMono);
  color: var(--colorBrandForeground);
  font-size: 12px;
  white-space: nowrap;
}

.lesson h3 {
  margin: 0 0 4px;
  font-size: 15px;
}

.lesson-meta {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.status-line {
  margin-top: 6px;
  color: var(--colorPaletteYellowForeground);
}

.lesson-content {
  margin: 8px 0 0;
  color: var(--colorNeutralForeground2);
}

.lesson-content.muted {
  color: var(--colorNeutralForeground3);
}

.terminal {
  width: 100%;
  max-height: 70vh;
  overflow: auto;
  margin: 0;
  padding: 14px;
  border: 1px solid var(--colorNeutralStroke2);
  border-radius: var(--radiusM);
  background-color: var(--colorNeutralBackground1);
  color: var(--colorNeutralForeground1);
  font-family: var(--fontFamilyMono);
  font-size: 13px;
  line-height: 1.5;
  white-space: pre-wrap;
}

.empty {
  min-height: 100px;
  display: grid;
  place-items: center;
  color: var(--colorNeutralForeground3);
  border: 1px dashed var(--colorNeutralStroke2);
  border-radius: var(--radiusM);
}

@media (max-width: 900px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .rail {
    position: static;
    height: auto;
    display: flex;
    gap: 4px;
    overflow-x: auto;
    border-right: 0;
    border-bottom: 1px solid var(--colorNeutralStroke2);
  }

  .nav-item {
    width: auto;
    white-space: nowrap;
    margin: 0;
  }

  .content {
    padding: 16px;
  }

  .metrics,
  .grid.two {
    grid-template-columns: 1fr;
  }

  .page-head {
    flex-direction: column;
  }

  .toolbar {
    width: 100%;
    justify-content: flex-start;
  }

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