:root {
  color-scheme: dark;
  --bg: #05070b;
  --panel: rgba(18, 22, 32, 0.82);
  --panel-strong: rgba(27, 33, 48, 0.94);
  --line: rgba(137, 180, 255, 0.18);
  --text: #eef4ff;
  --muted: #8f9bb1;
  --cyan: #48d8ff;
  --violet: #8b5cf6;
  --good: #4ade80;
  --bad: #fb7185;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at 18% 12%, rgba(72, 216, 255, 0.17), transparent 26rem),
    radial-gradient(circle at 82% 10%, rgba(139, 92, 246, 0.18), transparent 24rem),
    linear-gradient(135deg, #05070b, #0d111a 54%, #05070b);
  color: var(--text);
}

.shell {
  width: min(1440px, calc(100vw - 40px));
  margin: 0 auto;
  padding: 28px 0 40px;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  margin-bottom: 24px;
}

h1,
h2,
h3,
p {
  margin: 0;
}

h1 {
  font-size: 34px;
  font-weight: 750;
  letter-spacing: 0;
}

h2 {
  font-size: 22px;
  font-weight: 720;
}

h3 {
  font-size: 24px;
  font-weight: 760;
}

.eyebrow {
  color: var(--cyan);
  font-size: 12px;
  font-weight: 760;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.status {
  min-width: 260px;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(7, 10, 16, 0.76);
  text-align: right;
  box-shadow: 0 0 32px rgba(72, 216, 255, 0.08);
}

.status span {
  display: block;
  color: var(--good);
  font-weight: 800;
}

.status small {
  color: var(--muted);
}

.tabs {
  display: flex;
  gap: 10px;
  margin-bottom: 18px;
  border-bottom: 1px solid var(--line);
  padding-bottom: 10px;
}

.tab {
  color: var(--muted);
  background: rgba(18, 22, 32, 0.7);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 14px;
  cursor: pointer;
}

.tab.active {
  color: var(--text);
  border-color: rgba(72, 216, 255, 0.55);
  box-shadow: 0 0 24px rgba(72, 216, 255, 0.12);
}

.hidden {
  display: none;
}

.grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 14px;
  margin-bottom: 14px;
}

.panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: linear-gradient(180deg, var(--panel), rgba(10, 13, 21, 0.82));
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.32);
  padding: 18px;
  backdrop-filter: blur(18px);
}

.hero {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  min-height: 170px;
}

.hero p:not(.eyebrow),
.panel p:not(.eyebrow) {
  color: var(--muted);
  line-height: 1.45;
  margin-top: 8px;
}

.rings {
  display: grid;
  grid-template-columns: repeat(2, 112px);
  gap: 10px;
  align-content: center;
}

.rings div {
  aspect-ratio: 1;
  display: grid;
  place-content: center;
  text-align: center;
  border-radius: 50%;
  border: 1px solid rgba(72, 216, 255, 0.34);
  background: radial-gradient(circle, rgba(72, 216, 255, 0.16), rgba(139, 92, 246, 0.05));
}

.rings strong {
  font-size: 28px;
}

.rings span {
  color: var(--muted);
  font-size: 12px;
}

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 14px;
  margin-bottom: 14px;
}

select,
.link {
  color: var(--text);
  background: var(--panel-strong);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 12px;
  text-decoration: none;
}

.filters {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.subtle {
  color: var(--muted);
  font-size: 13px;
  margin-top: 6px;
}

.table-panel {
  margin-top: 14px;
}

.course-hero {
  display: flex;
  justify-content: space-between;
  gap: 28px;
  align-items: stretch;
  margin-bottom: 14px;
}

.course-hero > div:first-child {
  max-width: 780px;
}

.study-grid {
  min-width: 360px;
  display: grid;
  grid-template-columns: repeat(2, minmax(120px, 1fr));
  gap: 10px;
}

.study-grid div {
  background: rgba(72, 216, 255, 0.07);
  border: 1px solid rgba(72, 216, 255, 0.18);
  border-radius: 8px;
  padding: 12px;
}

.study-grid strong {
  display: block;
  font-size: 22px;
}

.study-grid span {
  color: var(--muted);
  font-size: 12px;
}

.concept-bars {
  display: grid;
  gap: 10px;
}

.bar-row {
  display: grid;
  grid-template-columns: 220px 1fr 54px;
  gap: 12px;
  align-items: center;
}

.bar-label,
.bar-count {
  color: #d9e6f8;
  font-size: 13px;
}

.bar-track {
  height: 10px;
  background: rgba(143, 155, 177, 0.16);
  border-radius: 999px;
  overflow: hidden;
}

.bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--cyan), var(--violet));
}

.course-layout {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 14px;
  margin-top: 14px;
}

.lesson-list {
  display: grid;
  gap: 8px;
  align-content: start;
}

.lesson-button {
  width: 100%;
  text-align: left;
  color: var(--text);
  background: rgba(12, 16, 24, 0.74);
  border: 1px solid rgba(137, 180, 255, 0.15);
  border-radius: 8px;
  padding: 11px 12px;
  cursor: pointer;
}

.lesson-button.active {
  border-color: rgba(72, 216, 255, 0.55);
  background: rgba(72, 216, 255, 0.1);
}

.lesson-detail {
  min-height: 430px;
}

.lesson-detail dl {
  display: grid;
  gap: 14px;
}

.lesson-detail dt {
  color: var(--cyan);
  font-weight: 760;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.lesson-detail dd {
  margin: 5px 0 0;
  color: #dbe6f7;
  line-height: 1.55;
}

.notes-grid {
  margin-top: 14px;
}

.table-scroll {
  max-height: 350px;
  overflow: auto;
  border: 1px solid rgba(137, 180, 255, 0.12);
  border-radius: 8px;
}

.table-scroll.compact {
  max-height: 430px;
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 860px;
}

th,
td {
  padding: 12px 14px;
  border-bottom: 1px solid rgba(137, 180, 255, 0.11);
  text-align: left;
  font-size: 13px;
}

th {
  position: sticky;
  top: 0;
  background: #111724;
  color: #b9c7dd;
  z-index: 1;
}

td {
  color: #e5edfb;
}

.positive {
  color: var(--good);
}

.negative {
  color: var(--bad);
}

@media (max-width: 1100px) {
  .grid {
    grid-template-columns: 1fr 1fr;
  }

  .hero {
    grid-column: 1 / -1;
  }

  .course-hero,
  .course-layout {
    grid-template-columns: 1fr;
    display: grid;
  }

  .study-grid {
    min-width: 0;
  }
}