:root {
  color-scheme: light;
  --bg: #f5f7f8;
  --panel: #ffffff;
  --panel-soft: #f8fbfa;
  --line: #d9e1df;
  --text: #182527;
  --muted: #667577;
  --brand: #126b62;
  --brand-dark: #0b514a;
  --accent: #c27803;
  --ok: #0f7b4d;
  --warn: #a15c00;
  --bad: #b42318;
  --shadow: 0 12px 28px rgba(24, 37, 39, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
  font-size: 14px;
  line-height: 1.5;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
input,
textarea {
  font: inherit;
}

.shell {
  min-height: 100vh;
  display: grid;
  grid-template-rows: auto 1fr;
}

.topbar {
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 0 22px;
  background: #ffffff;
  border-bottom: 1px solid var(--line);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 18px;
}

.brand-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  color: #fff;
  background: var(--brand);
}

.nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav a {
  padding: 8px 12px;
  border: 1px solid transparent;
  border-radius: 7px;
  color: var(--muted);
  font-weight: 700;
}

.nav a.active,
.nav a:hover {
  color: var(--brand-dark);
  border-color: var(--line);
  background: var(--panel-soft);
}

.api-status {
  margin-left: auto;
  min-height: 26px;
  display: inline-flex;
  align-items: center;
  padding: 4px 8px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 800;
  white-space: nowrap;
}

.api-status.ok {
  color: var(--ok);
  background: #eaf8f0;
  border: 1px solid #c5ead6;
}

.api-status.warn {
  color: var(--warn);
  background: #fff4df;
  border: 1px solid #f3d29a;
}

.main-grid {
  display: grid;
  grid-template-columns: minmax(240px, 0.85fr) minmax(420px, 2fr) minmax(300px, 1fr);
  gap: 14px;
  padding: 14px;
  height: calc(100vh - 64px);
}

.practice-grid,
.report-grid {
  display: grid;
  grid-template-columns: 340px minmax(560px, 1fr);
  gap: 14px;
  padding: 14px;
  min-height: calc(100vh - 64px);
}

.practice-grid {
  align-items: start;
}

.panel {
  min-height: 0;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.panel-head {
  min-height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
}

.panel-head h1,
.panel-head h2,
.panel-head h3 {
  margin: 0;
}

.panel-head h1 {
  font-size: 20px;
}

.panel-head h2 {
  font-size: 16px;
}

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

.scroll {
  height: 100%;
  overflow: auto;
}

.course-list,
.question-list {
  display: grid;
  gap: 10px;
  padding: 12px;
}

.course-card,
.question-card,
.report-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: 10px;
}

.course-card.active,
.question-card.active {
  border-color: var(--brand);
  background: #f3fbf8;
}

.course-card strong,
.question-card strong {
  display: block;
  margin-bottom: 4px;
}

.question-source {
  color: var(--brand);
  font-size: 12px;
  font-weight: 700;
  line-height: 1.45;
  margin-top: 6px;
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 8px;
}

.tag {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  padding: 3px 7px;
  border-radius: 6px;
  background: #eef4f3;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.tag.ok {
  color: var(--ok);
  background: #eaf8f0;
}

.tag.warn {
  color: var(--warn);
  background: #fff4df;
}

.chat-panel {
  display: grid;
  grid-template-rows: auto 1fr auto;
}

.chat-title {
  display: grid;
  gap: 2px;
}

.chat-body {
  display: grid;
  align-content: start;
  gap: 12px;
  padding: 14px;
  overflow: auto;
}

.message {
  max-width: 82%;
  border-radius: 8px;
  padding: 11px 12px;
  border: 1px solid var(--line);
  background: #fff;
}

.message.agent {
  justify-self: start;
  background: #f3fbf8;
  border-color: #c9dfdb;
}

.message.student {
  justify-self: end;
  color: #fff;
  background: var(--brand);
  border-color: var(--brand);
}

.message h3 {
  margin: 0 0 6px;
  font-size: 14px;
}

.message.streaming::after {
  content: "";
  display: inline-block;
  width: 7px;
  height: 1em;
  margin-left: 3px;
  vertical-align: -2px;
  background: currentColor;
  animation: blink 0.9s steps(2, start) infinite;
}

@keyframes blink {
  50% {
    opacity: 0;
  }
}

.markdown-body {
  white-space: normal;
}

.markdown-body p {
  margin: 0 0 8px;
}

.markdown-body h3,
.markdown-body h4 {
  margin: 8px 0 6px;
}

.markdown-body ul,
.markdown-body ol {
  margin: 6px 0 8px;
  padding-left: 20px;
}

.markdown-body code {
  padding: 1px 4px;
  border-radius: 4px;
  background: #e8eeee;
}

.markdown-body pre {
  overflow: auto;
  padding: 8px;
  border-radius: 6px;
  background: #172527;
  color: #f6fbf9;
}

.chat-input {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px;
  padding: 12px;
  border-top: 1px solid var(--line);
}

.chat-input input,
.answer-box textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 7px;
  padding: 9px 10px;
}

.fill-blank-list {
  display: grid;
  gap: 8px;
}

.blank-input {
  display: grid;
  grid-template-columns: 72px 1fr;
  align-items: center;
  gap: 8px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: #fff;
}

.blank-input span {
  color: var(--muted);
  font-weight: 800;
}

.blank-input input {
  min-width: 0;
  border: 1px solid #cbd8d5;
  border-radius: 6px;
  padding: 8px 9px;
}

.blank-result-list {
  margin: 8px 0;
  padding-left: 18px;
}

.blank-result-list li {
  margin: 4px 0;
}

.blank-result-list .ok {
  color: #126b62;
}

.blank-result-list .warn {
  color: #9a4b16;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 36px;
  border: 1px solid var(--line);
  border-radius: 7px;
  padding: 8px 12px;
  background: #fff;
  color: var(--text);
  font-weight: 800;
  cursor: pointer;
}

.btn.primary {
  color: #fff;
  background: var(--brand);
  border-color: var(--brand);
}

.btn.primary:hover {
  background: var(--brand-dark);
}

.source-panel {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
}

.source-content {
  padding: 12px;
  overflow: auto;
}

.textbook-image {
  width: 100%;
  display: block;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f4f6f6;
  margin-bottom: 12px;
}

.source-panel.media-active .textbook-image {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(18, 107, 98, 0.12);
}

.media-callout {
  border: 1px solid #cfe4df;
  border-radius: 6px;
  padding: 12px;
  background: #eef8f4;
  color: #24413d;
}

.media-callout p {
  margin: 6px 0 0;
  font-size: 0.92rem;
  line-height: 1.55;
}

.media-callout-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 4px;
}

.media-callout-head span {
  flex: 0 0 auto;
  border: 1px solid #a8d0c8;
  border-radius: 999px;
  padding: 3px 8px;
  background: #fff;
  color: var(--brand-dark);
  font-size: 0.78rem;
  font-weight: 700;
}

.source-block {
  border-left: 4px solid var(--brand);
  padding: 8px 10px;
  background: #f6fbf9;
  border-radius: 0 8px 8px 0;
}

.source-block p {
  margin: 0 0 8px;
}

.question-stage {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
}

.question-main {
  padding: 14px;
  overflow: auto;
}

.question-stem {
  font-size: 18px;
  font-weight: 800;
  margin-bottom: 12px;
}

.inline-blank {
  display: inline-block;
  width: 86px;
  height: 1.05em;
  margin: 0 4px;
  vertical-align: -0.18em;
  border-bottom: 2px solid #7d9290;
}

.options {
  display: grid;
  gap: 8px;
  margin: 12px 0;
}

.option {
  display: grid;
  grid-template-columns: 34px 1fr;
  align-items: center;
  gap: 8px;
  min-height: 42px;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.option-key {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: #eef4f3;
  color: var(--brand);
  font-weight: 900;
}

.option.selected {
  border-color: var(--brand);
  background: #f3fbf8;
}

.answer-box {
  display: grid;
  gap: 8px;
  padding: 12px;
  border-top: 1px solid var(--line);
}

.action-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.judgement {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: var(--panel-soft);
}

.explanation-box {
  border-left: 4px solid var(--accent);
}

.study-guide {
  display: grid;
  gap: 8px;
  margin-top: 10px;
  padding: 10px;
  border: 1px solid #cfe4df;
  border-radius: 8px;
  background: #f6fbf9;
}

.study-guide p {
  margin: 0;
}

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

.prompt-link {
  text-decoration: none;
}

.kpi-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  padding: 12px;
}

.kpi-grid.compact {
  grid-template-columns: 1fr;
}

.kpi {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: #fff;
}

.kpi span {
  display: block;
  color: var(--muted);
}

.kpi strong {
  display: block;
  margin-top: 4px;
  font-size: 24px;
}

.report-body {
  display: grid;
  gap: 12px;
  padding: 12px;
}

.report-line {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.next-list {
  margin: 8px 0 0;
  padding-left: 20px;
}

.bar {
  height: 10px;
  border-radius: 99px;
  background: #e8eeee;
  overflow: hidden;
}

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

@media (max-width: 1040px) {
  .main-grid,
  .practice-grid,
  .report-grid {
    grid-template-columns: 1fr;
    height: auto;
  }

  .panel {
    min-height: 320px;
  }
}

@media (max-width: 760px) {
  .topbar {
    height: auto;
    align-items: flex-start;
    flex-direction: column;
    padding: 12px;
  }

  .nav {
    width: 100%;
    overflow-x: auto;
  }

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