:root {
  --bg: #f6f7f4;
  --ink: #20242a;
  --muted: #667085;
  --line: #d8ded8;
  --panel: #ffffff;
  --green: #27715d;
  --blue: #2f5f98;
  --red: #b14242;
  --amber: #b67a2a;
  --soft-green: #e8f2ee;
  --soft-blue: #e8eef7;
  --shadow: 0 18px 48px rgba(32, 36, 42, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: "Segoe UI", "Yu Gothic UI", "Meiryo", sans-serif;
}

button,
input,
select {
  font: inherit;
}

button {
  border: 0;
  border-radius: 6px;
  background: var(--green);
  color: #fff;
  cursor: pointer;
  min-height: 42px;
  padding: 0 16px;
}

button:hover {
  filter: brightness(0.96);
}

button.ghost {
  background: #fff;
  color: var(--ink);
  border: 1px solid var(--line);
}

button.danger,
button.ghost.danger {
  color: var(--red);
}

input,
select {
  width: 100%;
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 8px 10px;
  background: #fff;
  color: var(--ink);
}

label {
  display: grid;
  gap: 7px;
  color: var(--muted);
  font-size: 13px;
}

.app-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
}

.sidebar {
  background: #1f2d2b;
  color: #fff;
  padding: 26px 20px;
  display: flex;
  flex-direction: column;
  gap: 22px;
}

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

.brand-mark {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  border-radius: 8px;
  background: #e7be52;
  color: #1f2d2b;
  font-weight: 800;
}

.brand h1,
.brand p,
.topbar h2,
.topbar p,
.section-title h3,
.section-title span {
  margin: 0;
}

.brand h1 {
  font-size: 17px;
}

.brand p {
  color: #b9c7c3;
  font-size: 13px;
}

.role-switch {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
  padding: 4px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 8px;
}

.role-switch button {
  min-height: 38px;
  background: transparent;
  color: #dce6e3;
}

.role-switch button.active {
  background: #fff;
  color: #1f2d2b;
}

.sidebar-block {
  display: grid;
  gap: 5px;
  padding: 16px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 8px;
}

.sidebar-block span {
  color: #b9c7c3;
  font-size: 13px;
}

main {
  min-width: 0;
  padding: 28px;
}

.view {
  display: none;
}

.view.active {
  display: grid;
  gap: 20px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.eyebrow {
  color: var(--green);
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 0;
  text-transform: uppercase;
}

.topbar h2 {
  font-size: 28px;
}

.grid {
  display: grid;
  gap: 18px;
}

.grid.two {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.learner-grid {
  grid-template-columns: minmax(280px, 0.8fr) minmax(0, 1.2fr);
}

.panel,
.metric {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.panel {
  padding: 20px;
  display: grid;
  gap: 16px;
}

.wide {
  min-width: 0;
}

.section-title {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 14px;
}

.section-title h3 {
  font-size: 18px;
}

.section-title span {
  color: var(--muted);
  font-size: 13px;
}

.countdown {
  margin: 0;
  padding: 12px 14px;
  border-radius: 8px;
  background: var(--soft-blue);
  color: var(--blue);
  font-weight: 700;
}

.table-wrap {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 820px;
}

th,
td {
  border-bottom: 1px solid var(--line);
  padding: 12px 10px;
  text-align: left;
  vertical-align: middle;
}

th {
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

td {
  font-size: 14px;
}

.row-actions {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.row-actions button {
  min-height: 34px;
  padding: 0 10px;
  font-size: 13px;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.metric {
  padding: 18px;
  display: grid;
  gap: 7px;
}

.metric span {
  color: var(--muted);
  font-size: 13px;
}

.metric strong {
  font-size: 24px;
}

.metric.accent {
  background: var(--soft-green);
  border-color: #c6ddd4;
}

.user-select {
  width: min(320px, 100%);
}

.study-tools {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.study-tools button.active {
  background: var(--blue);
  color: #fff;
}

.assignment-empty,
.empty {
  color: var(--muted);
  padding: 18px;
  border: 1px dashed var(--line);
  border-radius: 8px;
}

.assignment-tools {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.question-checks {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.question-check {
  display: grid;
  grid-template-columns: 22px minmax(0, 1fr);
  gap: 8px;
  align-items: start;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
  background: #fbfcfb;
}

.question-check input {
  width: 18px;
  min-height: 18px;
  margin-top: 2px;
}

.question-check strong {
  display: block;
  font-size: 13px;
}

.question-check span {
  color: var(--muted);
  display: block;
  font-size: 12px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.weakness-list,
.review-list {
  display: grid;
  gap: 12px;
}

.weak-row {
  display: grid;
  gap: 7px;
}

.weak-head {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-size: 14px;
}

.bar {
  height: 10px;
  background: #edf0ed;
  border-radius: 999px;
  overflow: hidden;
}

.bar span {
  display: block;
  height: 100%;
  background: var(--green);
}

.quiz-question {
  display: grid;
  gap: 16px;
}

.source {
  width: fit-content;
  color: var(--blue);
  background: var(--soft-blue);
  border-radius: 999px;
  padding: 5px 10px;
  font-size: 12px;
  font-weight: 700;
}

.retry-note {
  display: block;
  border-left: 4px solid var(--amber);
  background: #fff7e7;
  border-radius: 6px;
  color: #6f4c1d;
  padding: 10px 12px;
  font-size: 13px;
  font-weight: 700;
}

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

.choice-list label {
  grid-template-columns: 22px minmax(0, 1fr);
  align-items: start;
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
}

.choice-list input {
  width: 18px;
  min-height: 18px;
}

.result {
  padding: 14px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: #fbfcfb;
}

.result.correct {
  border-color: #b9d8c8;
  background: #edf7f2;
}

.result.wrong {
  border-color: #ecc3bd;
  background: #fff2f0;
}

.review-item {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
  display: grid;
  gap: 8px;
  background: #fff;
}

.review-item header {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  color: var(--muted);
  font-size: 13px;
}

.badge {
  border-radius: 999px;
  padding: 3px 9px;
  font-weight: 700;
  background: #eef0ee;
  color: var(--muted);
}

.badge.wrong {
  background: #fff2f0;
  color: var(--red);
}

.badge.todo {
  background: #fff7e7;
  color: var(--amber);
}

@media (max-width: 920px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
    padding: 14px;
    gap: 12px;
  }

  .brand-mark {
    width: 40px;
    height: 40px;
  }

  .brand h1 {
    font-size: 15px;
  }

  .brand p {
    font-size: 12px;
  }

  .role-switch {
    position: sticky;
    top: 0;
    z-index: 10;
  }

  .role-switch button {
    min-height: 44px;
  }

  .sidebar-block {
    grid-template-columns: 1fr auto;
    align-items: center;
    padding: 10px 12px;
  }

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

  main {
    padding: 14px;
  }

  .topbar,
  .section-title {
    align-items: stretch;
    flex-direction: column;
  }

  .question-checks {
    grid-template-columns: 1fr;
  }

  .panel {
    padding: 16px;
    box-shadow: none;
  }

  .topbar h2 {
    font-size: 22px;
  }

  .metrics {
    gap: 10px;
  }

  .metric {
    grid-template-columns: 1fr auto;
    align-items: center;
    padding: 14px;
  }

  .metric strong {
    font-size: 20px;
    text-align: right;
  }

  .quiz-panel {
    order: -1;
  }

  .quiz-question {
    gap: 14px;
  }

  .study-tools {
    grid-template-columns: 1fr;
  }

  .choice-list label {
    min-height: 52px;
    padding: 14px;
  }

  button,
  input,
  select {
    min-height: 46px;
  }
}

@media (max-width: 560px) {
  .sidebar-block {
    display: none;
  }

  .view.active {
    gap: 14px;
  }

  .review-item,
  .result {
    font-size: 14px;
  }

  .weak-head {
    font-size: 13px;
  }
}