:root {
  color-scheme: light;
  --bg: #eef2f5;
  --surface: #ffffff;
  --surface-soft: #f7fafc;
  --ink: #16212d;
  --muted: #657484;
  --line: #d8e0e7;
  --accent: #176b87;
  --accent-soft: #e7f3f7;
  --green: #2d7d46;
  --green-soft: #edf8f1;
  --warn: #9b5b00;
  --warn-soft: #fff7e6;
  --danger: #a33a3a;
  --danger-soft: #fff0f0;
  --shadow: 0 8px 24px rgba(24, 39, 56, 0.08);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-width: 320px;
  background: var(--bg);
  color: var(--ink);
  font-family: "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
  line-height: 1.45;
}

.learning-app {
  display: grid;
  grid-template-columns: 232px minmax(0, 1fr) 360px;
  gap: 14px;
  max-width: 1780px;
  min-height: 100vh;
  margin: 0 auto;
  padding: 14px;
}

.learning-sidebar,
.learning-topbar,
.panel,
.rail-panel,
.status-card,
.summary-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.learning-sidebar {
  position: sticky;
  top: 14px;
  align-self: start;
  display: grid;
  gap: 16px;
  padding: 14px;
}

.side-brand h1 {
  margin: 6px 0 10px;
  font-size: 20px;
  line-height: 1.25;
  letter-spacing: 0;
}

.brand-kicker,
.eyebrow {
  color: var(--accent);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

.mode-pill,
.status-badge,
.tag {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  padding: 2px 8px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  white-space: nowrap;
}

.status-badge.is-safe,
.tag.safe { background: var(--green-soft); color: var(--green); }
.status-badge.is-warn,
.tag.warn { background: var(--warn-soft); color: var(--warn); }
.status-badge.is-danger,
.tag.danger { background: var(--danger-soft); color: var(--danger); }

.side-nav {
  display: grid;
  gap: 6px;
}

.side-nav a,
.text-link,
button {
  min-height: 34px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--surface-soft);
  color: var(--ink);
  text-decoration: none;
  font: inherit;
  font-size: 13px;
}

.side-nav a {
  display: flex;
  align-items: center;
  padding: 7px 10px;
}

.side-nav a.is-active,
.side-nav a:hover,
.text-link:hover,
button:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: #f0f8fb;
}

button {
  padding: 6px 10px;
  cursor: pointer;
}

button:focus-visible,
a:focus-visible,
tr[data-learning-row]:focus-visible {
  outline: 3px solid rgba(23, 107, 135, 0.38);
  outline-offset: 2px;
}

.side-safety {
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
}

.side-safety span,
.side-safety p,
.muted {
  color: var(--muted);
  font-size: 12px;
}

.side-safety strong {
  display: block;
  margin: 4px 0;
  font-size: 15px;
}

.side-safety p { margin: 0; }

.learning-main {
  min-width: 0;
}

.learning-topbar {
  position: sticky;
  top: 14px;
  z-index: 8;
  display: grid;
  grid-template-columns: minmax(180px, 1fr) auto;
  gap: 10px 14px;
  align-items: center;
  padding: 14px 16px;
}

.learning-topbar h2 {
  margin: 2px 0 0;
  font-size: 22px;
  letter-spacing: 0;
}

.phase-label {
  color: var(--muted);
  font-size: 12px;
}

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

.text-link {
  display: inline-flex;
  align-items: center;
  padding: 6px 10px;
}

.risk-statement {
  grid-column: 1 / -1;
  margin: 0;
  color: var(--danger);
  font-size: 13px;
  font-weight: 700;
}

.learning-canvas {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  padding-top: 14px;
}

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

.overview-grid,
.learning-strip,
.review-grid {
  display: grid;
  gap: 10px;
}

.overview-grid {
  grid-column: 1 / -1;
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.learning-strip {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.status-card,
.summary-card {
  min-width: 0;
  min-height: 78px;
  padding: 12px;
}

.status-card {
  border-left: 4px solid var(--accent);
}

.summary-card {
  border-left: 4px solid #40566a;
}

.status-card span,
.summary-card span,
.review-grid span {
  display: block;
  color: var(--muted);
  font-size: 12px;
}

.status-card strong,
.summary-card strong,
.review-grid strong {
  display: block;
  margin-top: 5px;
  font-size: 17px;
  line-height: 1.25;
  word-break: break-word;
}

.status-card small {
  display: block;
  margin-top: 6px;
  color: var(--muted);
  font-size: 11px;
}

.panel,
.rail-panel {
  min-width: 0;
  padding: 14px;
}

.panel-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.panel-title h2 {
  margin: 2px 0 0;
  font-size: 16px;
  letter-spacing: 0;
}

.panel-title p {
  margin: 6px 0 0;
}

.panel-title-stack {
  align-items: flex-start;
}

.temperature-meter {
  height: 16px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #edf1f5;
}

.temperature-meter span {
  display: block;
  width: 40%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--green), #779044, var(--warn));
}

.meter-scale {
  display: flex;
  justify-content: space-between;
  margin-top: 6px;
  color: var(--muted);
  font-size: 11px;
}

.note-list,
.radar-list,
.paper-list {
  display: grid;
  gap: 8px;
  margin-top: 12px;
}

.note,
.radar-item,
.paper-item,
.explainer-card,
.explainer-empty {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
  background: var(--surface-soft);
}

.radar-item {
  display: grid;
  grid-template-columns: minmax(88px, 1fr) repeat(3, minmax(64px, .72fr));
  gap: 8px;
  align-items: center;
}

.radar-item strong,
.radar-item span {
  min-width: 0;
  word-break: break-word;
}

.segmented {
  display: inline-flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 4px;
}

.segmented button.is-active {
  color: #fff;
  border-color: var(--accent);
  background: var(--accent);
}

.table-wrap {
  width: 100%;
  overflow: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

table {
  width: 100%;
  min-width: 1080px;
  border-collapse: collapse;
}

th,
td {
  padding: 9px 10px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
  font-size: 13px;
}

th {
  position: sticky;
  top: 0;
  z-index: 1;
  background: #f4f7fa;
  color: #405061;
  font-weight: 700;
}

tbody tr {
  cursor: pointer;
}

tbody tr:hover {
  background: #f7fbfd;
}

.review-grid {
  grid-template-columns: repeat(6, minmax(0, 1fr));
}

.review-grid div {
  min-height: 74px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
}

.task-list,
.review-loop-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.task-card,
.checkpoint-card {
  display: grid;
  gap: 8px;
  min-height: 128px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
}

.task-card {
  cursor: pointer;
}

.task-card.is-active {
  border-color: var(--accent);
  background: #f0f8fb;
  box-shadow: inset 4px 0 0 var(--accent);
}

.task-card strong,
.checkpoint-card strong {
  font-size: 15px;
}

.task-card p,
.checkpoint-card p {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.task-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.scorecard-grid {
  display: grid;
  grid-template-columns: minmax(220px, .8fr) minmax(280px, 1.2fr) minmax(240px, 1fr);
  gap: 12px;
}

.score-meter-card,
.rubric-group,
.scorecard-notes {
  min-width: 0;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
}

.score-meter-card label,
.rubric-group span {
  display: block;
  color: var(--muted);
  font-size: 12px;
  margin-bottom: 8px;
}

.score-meter-card input[type="range"] {
  width: 100%;
  margin: 4px 0 10px;
}

.score-meter {
  height: 12px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #edf1f5;
}

.score-meter span {
  display: block;
  width: 50%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--warn), var(--accent), var(--green));
}

.score-meter-card strong {
  display: block;
  margin-top: 8px;
  font-size: 18px;
}

.rubric-group {
  display: grid;
  gap: 12px;
}

.segmented.compact {
  justify-content: flex-start;
}

.segmented.compact button {
  min-height: 30px;
  padding: 5px 8px;
}

.scorecard-notes h3 {
  margin: 0 0 8px;
  font-size: 15px;
}

.scorecard-notes p {
  margin: 0 0 10px;
}

.checkpoint-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.checkpoint-actions button.is-active {
  color: #fff;
  border-color: var(--accent);
  background: var(--accent);
}

.loop-summary {
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-size: 13px;
}

.loop-summary strong {
  color: var(--ink);
  font-size: 15px;
}

.boundary-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  padding: 0;
  margin: 0 0 12px;
  list-style: none;
}

.boundary-list li {
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
  font-size: 13px;
}

.learning-rail {
  position: sticky;
  top: 14px;
  align-self: start;
  display: grid;
  gap: 14px;
}

.rail-panel {
  box-shadow: var(--shadow);
}

.rail-panel h2 {
  margin: 2px 0 0;
  font-size: 16px;
}

.explainer-empty {
  color: var(--muted);
  min-height: 152px;
}

.explainer-card h3 {
  margin: 0 0 10px;
  font-size: 17px;
}

.explainer-card dl {
  display: grid;
  gap: 8px;
  margin: 0;
}

.explainer-card dt {
  color: var(--muted);
  font-size: 12px;
}

.explainer-card dd {
  margin: -4px 0 0;
  font-size: 13px;
}

.paper-item p {
  margin: 8px 0 0;
}

.rail-safety p {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.learning-toast {
  position: fixed;
  right: 18px;
  bottom: 18px;
  max-width: min(420px, calc(100vw - 36px));
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #16212d;
  color: #fff;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity .16s ease, transform .16s ease;
  font-size: 13px;
}

.learning-toast.show {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 1280px) {
  .learning-app {
    grid-template-columns: 196px minmax(0, 1fr);
  }

  .learning-rail {
    grid-column: 2;
    position: static;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .rail-safety {
    grid-column: 1 / -1;
  }
}

@media (max-width: 920px) {
  .learning-app {
    grid-template-columns: 1fr;
    padding: 10px;
  }

  .learning-sidebar,
  .learning-topbar {
    position: static;
  }

  .learning-sidebar {
    grid-template-columns: minmax(180px, .7fr) minmax(0, 1fr);
    align-items: start;
  }

  .side-safety {
    grid-column: 1 / -1;
  }

  .side-nav {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .side-nav a {
    justify-content: center;
    min-height: 34px;
  }

  .learning-canvas,
  .learning-rail {
    grid-column: 1;
    grid-template-columns: 1fr;
  }

  .overview-grid,
  .learning-strip,
  .review-grid,
  .task-list,
  .review-loop-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .boundary-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .learning-topbar {
    grid-template-columns: 1fr;
  }

  .learning-actions {
    justify-content: flex-start;
  }

  .learning-sidebar {
    grid-template-columns: 1fr;
  }

  .side-nav,
  .overview-grid,
  .learning-strip,
  .review-grid,
  .task-list,
  .review-loop-list {
    grid-template-columns: 1fr;
  }

  .panel-title,
  .panel-title-stack {
    align-items: flex-start;
    flex-direction: column;
  }

  .segmented {
    justify-content: flex-start;
  }

  .radar-item {
    grid-template-columns: 1fr;
  }
}