/* Dashboard design system — AIEdu admin/teacher
 * ECharts-friendly color tokens + card components.
 * All colors map to CSS variables so dark mode works automatically.
 */

:root {
  /* Chart palette (10 distinct hues, brand-aware) */
  --c1: #2563eb; /* brand blue */
  --c2: #06b6d4; /* cyan */
  --c3: #10b981; /* emerald */
  --c4: #f59e0b; /* amber */
  --c5: #f43f5e; /* rose */
  --c6: #8b5cf6; /* violet */
  --c7: #ec4899; /* pink */
  --c8: #14b8a6; /* teal */
  --c9: #f97316; /* orange */
  --c10: #64748b; /* slate */

  /* Semantic chart states */
  --c-ok: #16a34a;
  --c-warn: #f59e0b;
  --c-bad: #dc2626;
  --c-info: #2563eb;
  --c-mute: #94a3b8;

  /* Surface for cards */
  --surface-1: var(--surface, #fff);
  --surface-2: var(--surface-2, #f8fafc);
  --line-soft: var(--line, #e2e8f0);
  --ink-1: var(--ink, #0f172a);
  --ink-2: var(--ink-2, #475569);
  --ink-3: var(--ink-3, #94a3b8);
}

[data-theme="dark"] {
  --c-mute: #475569;
  --surface-1: #0f172a;
  --surface-2: #1e293b;
  --line-soft: #334155;
  --ink-1: #f1f5f9;
  --ink-2: #cbd5e1;
  --ink-3: #94a3b8;
}

/* ============ Dashboard layout ============ */
.dash-grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}
.dash-grid.g2 { grid-template-columns: repeat(2, 1fr); }
.dash-grid.g3 { grid-template-columns: repeat(3, 1fr); }
.dash-grid.g4 { grid-template-columns: repeat(4, 1fr); }
.dash-grid.g5 { grid-template-columns: repeat(5, 1fr); }
@media (max-width: 1100px) { .dash-grid.g3, .dash-grid.g4 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 1300px) { .dash-grid.g5 { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 700px)  { .dash-grid.g2, .dash-grid.g3, .dash-grid.g4, .dash-grid.g5 { grid-template-columns: 1fr; } }

/* ============ KPI tile with sparkline ============ */
.kpi-tile {
  position: relative;
  background: var(--surface-1);
  border: 1px solid var(--line-soft);
  border-radius: 14px;
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-height: 110px;
  overflow: hidden;
}
.kpi-tile .kpi-label { font-size: 13px; color: var(--ink-3); font-weight: 500; display:flex; align-items:center; gap:6px; }
.kpi-tile .kpi-value { font-size: 32px; font-weight: 700; line-height: 1.1; color: var(--ink-1); margin-top: 2px; }
.kpi-tile .kpi-foot  { font-size: 12px; color: var(--ink-3); margin-top: 4px; }
.kpi-tile .kpi-delta { font-size: 12px; font-weight: 600; padding: 2px 8px; border-radius: 999px; display: inline-block; }
.kpi-tile .kpi-delta.up   { background: color-mix(in srgb, var(--c-ok)   14%, transparent); color: var(--c-ok); }
.kpi-tile .kpi-delta.down { background: color-mix(in srgb, var(--c-bad)  14%, transparent); color: var(--c-bad); }
.kpi-tile .kpi-delta.flat { background: color-mix(in srgb, var(--c-mute) 14%, transparent); color: var(--c-mute); }
.kpi-tile .kpi-spark { position: absolute; right: -6px; bottom: -6px; width: 100px; height: 48px; opacity: .85; pointer-events: none; }
.kpi-tile .kpi-icon  { width: 32px; height: 32px; border-radius: 10px; display: grid; place-items: center; background: color-mix(in srgb, var(--c1) 14%, transparent); color: var(--c1); }
.kpi-tile.toned-2 .kpi-icon { background: color-mix(in srgb, var(--c3) 14%, transparent); color: var(--c3); }
.kpi-tile.toned-3 .kpi-icon { background: color-mix(in srgb, var(--c4) 14%, transparent); color: var(--c4); }
.kpi-tile.toned-4 .kpi-icon { background: color-mix(in srgb, var(--c5) 14%, transparent); color: var(--c5); }
.kpi-tile.toned-5 .kpi-icon { background: color-mix(in srgb, var(--c6) 14%, transparent); color: var(--c6); }
.kpi-tile .kpi-top { display:flex; align-items:center; justify-content: space-between; gap:8px; }
.kpi-tile.bad   { border-color: color-mix(in srgb, var(--c-bad)  30%, var(--line-soft)); }
.kpi-tile.warn  { border-color: color-mix(in srgb, var(--c-warn) 30%, var(--line-soft)); }
.kpi-tile.ok    { border-color: color-mix(in srgb, var(--c-ok)   30%, var(--line-soft)); }

/* ============ Chart card ============ */
.chart-card {
  background: var(--surface-1);
  border: 1px solid var(--line-soft);
  border-radius: 14px;
  padding: 14px 16px 8px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.chart-card .chart-head {
  display: flex; align-items: flex-start; justify-content: space-between; gap: 8px; margin-bottom: 4px;
}
.chart-card .chart-head h3 { margin: 0; font-size: 15px; font-weight: 700; color: var(--ink-1); }
.chart-card .chart-head .chart-sub { font-size: 12px; color: var(--ink-3); margin-top: 2px; }
.chart-card .chart-head .chart-actions { display: flex; gap: 6px; align-items: center; }
.chart-card .chart-body { width: 100%; min-height: 240px; }
.chart-card .chart-legend { display: flex; flex-wrap: wrap; gap: 10px 14px; font-size: 12px; color: var(--ink-2); margin-top: 4px; }
.chart-card .chart-legend .dot { display: inline-block; width: 10px; height: 10px; border-radius: 2px; margin-right: 5px; vertical-align: middle; }

/* Compact chart for KPI strip */
.chart-mini { width: 100%; height: 60px; }

/* ============ Status pills (re-use existing) ============ */
.status-pill { padding: 2px 8px; border-radius: 999px; font-size: 11px; font-weight: 600; display: inline-block; }
.status-pill.ok    { background: color-mix(in srgb, var(--c-ok)   15%, transparent); color: var(--c-ok); }
.status-pill.warn  { background: color-mix(in srgb, var(--c-warn) 15%, transparent); color: var(--c-warn); }
.status-pill.bad   { background: color-mix(in srgb, var(--c-bad)  15%, transparent); color: var(--c-bad); }
.status-pill.info  { background: color-mix(in srgb, var(--c1)     15%, transparent); color: var(--c1); }
.status-pill.mute  { background: color-mix(in srgb, var(--c-mute) 15%, transparent); color: var(--c-mute); }

/* ============ Section header ============ */
.section-title {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  margin: 8px 0 4px;
}
.section-title h2 { margin: 0; font-size: 18px; font-weight: 700; color: var(--ink-1); }
.section-title .section-sub { font-size: 12px; color: var(--ink-3); margin-top: 2px; }

/* ============ Toolbar / filter chip ============ */
.toolbar {
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap; padding: 6px 0;
}
.toolbar .chip {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 12px; border-radius: 999px; font-size: 12.5px; font-weight: 500;
  border: 1px solid var(--line-soft); background: var(--surface-1); color: var(--ink-2);
  cursor: pointer; text-decoration: none; transition: all .15s ease;
}
.toolbar .chip:hover { border-color: var(--c1); color: var(--c1); }
.toolbar .chip.on { background: var(--c1); color: #fff; border-color: var(--c1); }
.toolbar .chip .count { background: color-mix(in srgb, var(--c1) 18%, transparent); color: var(--c1); padding: 0 6px; border-radius: 999px; font-size: 11px; }
.toolbar .chip.on .count { background: rgba(255,255,255,.25); color: #fff; }

/* ============ Data table with hover/scroll ============ */
.dash-table {
  width: 100%; border-collapse: separate; border-spacing: 0; font-size: 13px;
}
.dash-table thead th {
  text-align: left; font-weight: 600; color: var(--ink-2);
  padding: 10px 12px; border-bottom: 1px solid var(--line-soft);
  background: var(--surface-2);
  position: sticky; top: 0; z-index: 1;
}
.dash-table tbody td { padding: 10px 12px; border-bottom: 1px solid var(--line-soft); color: var(--ink-1); }
.dash-table tbody tr:hover td { background: color-mix(in srgb, var(--c1) 4%, transparent); }
.dash-table .num { font-variant-numeric: tabular-nums; text-align: right; }
.dash-table .progress-bar { display: flex; align-items: center; gap: 6px; }
.dash-table .progress-bar .bar { flex: 1; height: 6px; background: var(--line-soft); border-radius: 999px; overflow: hidden; }
.dash-table .progress-bar .bar i { display: block; height: 100%; background: var(--c1); border-radius: 999px; }

/* ============ Heatmap cell ============ */
.heat-cell {
  display: inline-block; min-width: 28px; text-align: center;
  padding: 4px 6px; border-radius: 6px; font-size: 12px; font-weight: 600;
  background: var(--line-soft); color: var(--ink-2);
}
.heat-cell.lv-1 { background: color-mix(in srgb, var(--c-bad)  70%, transparent); color: #fff; }
.heat-cell.lv-2 { background: color-mix(in srgb, var(--c-warn) 70%, transparent); color: #fff; }
.heat-cell.lv-3 { background: color-mix(in srgb, var(--c4)     60%, transparent); color: #fff; }
.heat-cell.lv-4 { background: color-mix(in srgb, var(--c-ok)   70%, transparent); color: #fff; }
.heat-cell.lv-0 { background: color-mix(in srgb, var(--c-mute) 30%, transparent); color: var(--ink-3); }

/* ============ Page heading ============ */
.dash-heading {
  display: flex; align-items: flex-end; justify-content: space-between; gap: 12px; margin: 0 0 16px;
  flex-wrap: wrap;
}
.dash-heading h1 { margin: 0; font-size: 24px; font-weight: 700; color: var(--ink-1); }
.dash-heading .eyebrow { font-size: 12px; color: var(--ink-3); margin-bottom: 4px; }
.dash-heading p { margin: 4px 0 0; color: var(--ink-2); font-size: 14px; }

/* ============ Empty / loading states ============ */
.chart-card .empty {
  display: flex; align-items: center; justify-content: center; min-height: 180px;
  color: var(--ink-3); font-size: 13px;
}
.chart-card.loading .chart-body { opacity: 0.5; transition: opacity .2s; }

/* ============ Chart tabs (admin/index.html) ============ */
.chart-tabs {
  display: flex; gap: 4px;
  border-bottom: 1px solid var(--line-soft);
  margin-top: 16px;
  flex-wrap: wrap;
}
.chart-tab {
  appearance: none;
  background: transparent;
  border: 0;
  padding: 10px 16px;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--ink-2);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: color .15s ease, border-color .15s ease;
}
.chart-tab:hover { color: var(--c1); }
.chart-tab.on {
  color: var(--c1);
  border-bottom-color: var(--c1);
  font-weight: 600;
}
.chart-tab:focus-visible { outline: 2px solid var(--c1); outline-offset: -2px; border-radius: 4px; }

/* ============ Tab panes (admin/index.html) ============ */
.tab-pane { margin-top: 12px; }
.tab-pane[hidden] { display: none; }
.tab-pane.on { display: block; animation: tab-pane-fade .18s ease; }
@keyframes tab-pane-fade {
  from { opacity: 0; transform: translateY(4px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ============ Pie grid (multi-pie container) ============ */
.pie-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 14px;
  margin-top: 6px;
}
.pie-tile {
  background: var(--surface-2);
  border: 1px solid var(--line-soft);
  border-radius: 12px;
  padding: 10px 8px 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  align-items: center;
  text-align: center;
}
.pie-tile .echart { width: 100%; }
.pie-tile-label {
  font-size: 13px;
  color: var(--ink-2);
  font-weight: 600;
  margin-top: 2px;
}
.pie-tile-label small { display: block; color: var(--ink-3); font-weight: 400; font-size: 11px; }

/* ============ Skill status: compact, decision-first alternative to mini pies ============ */
.skill-status-card-wrap { background: var(--surface-1); }
.skill-status-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 12px; margin-top: 8px; }
.skill-status-card { background: var(--surface-2); border: 1px solid var(--line-soft); border-radius: 12px; padding: 14px; }
.skill-status-link { display: block; color: inherit; text-decoration: none; }
.skill-status-link:hover { border-color: var(--brand); box-shadow: 0 4px 14px color-mix(in srgb, var(--brand) 12%, transparent); }
.skill-status-head, .skill-status-summary { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.skill-status-head b { color: var(--ink-1); font-size: 15px; }
.skill-status-bar { height: 12px; display: flex; overflow: hidden; border-radius: 999px; background: var(--line-soft); margin: 14px 0 10px; }
.skill-status-bar span { min-width: 0; transition: width .2s ease; }
.skill-status-bar .state-intervene { background: #dc2626; }
.skill-status-bar .state-support { background: #f59e0b; }
.skill-status-bar .state-ok { background: #16a34a; }
.skill-status-bar .state-nodata { background: #94a3b8; }
.skill-status-summary { font-size: 13px; color: var(--ink-2); }
.skill-status-summary b { color: var(--ink-1); }
.skill-status-breakdown { display: flex; flex-wrap: wrap; gap: 5px; margin-top: 9px; color: var(--ink-3); font-size: 12px; line-height: 1.35; }
.skill-status-breakdown i { font-style: normal; color: var(--line); }
@media (max-width: 620px) { .skill-status-grid { grid-template-columns: 1fr; } }

/* Submission first: show the student's original work before review aids. */
.submission-work { border: 2px solid color-mix(in srgb, var(--brand) 26%, var(--line-soft)); margin-bottom: 14px; }
.submission-work-text { white-space: pre-wrap; line-height: 1.72; margin-top: 14px; padding: 16px; border-radius: 10px; background: var(--surface-2); color: var(--ink-1); }
.submission-files { margin-top: 14px; padding-top: 12px; border-top: 1px solid var(--line-soft); }
.submission-file-row { display: flex; justify-content: space-between; align-items: center; gap: 10px; padding: 10px 0; border-top: 1px solid var(--line-soft); font-size: 13px; }
.submission-file-row small { color: var(--ink-3); margin-left: 5px; }
@media (max-width: 620px) { .submission-file-row { align-items: flex-start; flex-direction: column; } }

/* ============ Funnel-card wrapper ============ */
.funnel-card {
  /* Khu vực dành cho funnel — dùng nền nhạt để funnel nổi bật hơn. */
  background: linear-gradient(180deg, var(--surface-1), color-mix(in srgb, var(--c1) 4%, var(--surface-1)));
}
[data-theme="dark"] .funnel-card {
  background: linear-gradient(180deg, var(--surface-1), color-mix(in srgb, var(--c1) 6%, var(--surface-1)));
}

/* ============ KPI tile with inline sparkline (compact) ============ */
.kpi-tile.kpi-spark {
  position: relative;
  min-height: 110px;
}
.kpi-tile.kpi-spark .spark-area {
  position: absolute;
  right: 0;
  bottom: 0;
  width: 100%;
  height: 36px;
  pointer-events: none;
  opacity: .8;
}

/* ============ Class hub ============ */
.class-hub { margin-top: 20px; padding: 18px; border: 1px solid var(--line-soft); border-radius: 16px; background: var(--surface-1); }
.class-hub-toolbar { display: flex; justify-content: space-between; align-items: end; gap: 12px; padding-bottom: 16px; border-bottom: 1px solid var(--line-soft); }
.class-picker { display: grid; gap: 5px; min-width: min(100%, 330px); }
.class-picker select, .class-create-form input, .join-class-card input { min-height: 40px; padding: 8px 10px; border: 1px solid var(--line-soft); border-radius: 9px; background: var(--surface-2); color: var(--ink-1); font: inherit; }
.class-create { position: relative; }
.class-create summary { list-style: none; cursor: pointer; }
.class-create summary::-webkit-details-marker { display: none; }
.class-create-form { position: absolute; z-index: 3; right: 0; top: calc(100% + 8px); width: min(340px, 88vw); padding: 14px; display: grid; gap: 8px; border: 1px solid var(--line-soft); border-radius: 12px; background: var(--surface-1); box-shadow: 0 14px 34px rgba(15, 37, 72, .16); }
.class-hub-grid { display: grid; grid-template-columns: 1.05fr 1fr 1fr; gap: 14px; margin-top: 16px; }
.class-code-card, .class-hub-panel, .class-summary-card { border: 1px solid var(--line-soft); border-radius: 12px; background: var(--surface-2); padding: 16px; }
.class-code-card { background: linear-gradient(135deg, color-mix(in srgb, var(--brand) 10%, var(--surface-2)), var(--surface-2)); }
.class-card-kicker { color: var(--ink-3); font-size: 12px; font-weight: 700; }
.join-code { display: block; margin: 10px 0 8px; color: var(--brand); font-size: clamp(26px, 3vw, 34px); letter-spacing: .1em; }
.class-code-card p { margin: 0; font-size: 13px; color: var(--ink-2); line-height: 1.5; }
.class-code-actions { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 14px; }
.class-code-actions form { margin: 0; }
.class-panel-head { display: flex; align-items: start; justify-content: space-between; gap: 8px; }
.class-panel-head h3 { margin: 3px 0 0; font-size: 17px; }
.class-member-list, .class-course-list { margin: 12px 0 0; padding: 0; list-style: none; }
.class-member-list li, .class-course-list li { display: flex; align-items: center; justify-content: space-between; gap: 8px; padding: 8px 0; border-top: 1px solid var(--line-soft); font-size: 13px; }
.class-course-list a { color: var(--brand); font-weight: 650; text-decoration: none; }
.class-course-list a:hover { text-decoration: underline; }
.text-btn { padding: 0; border: 0; background: transparent; color: var(--bad); font: inherit; cursor: pointer; }
.class-summary-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 12px; margin-top: 16px; }
.class-summary-card { color: inherit; text-decoration: none; transition: border-color .15s ease, transform .15s ease; }
.class-summary-card:hover { border-color: var(--brand); transform: translateY(-2px); }
.class-summary-card h3 { margin: 6px 0; font-size: 18px; }
.class-summary-card p { margin: 0 0 12px; color: var(--ink-2); font-size: 13px; }
.class-summary-card > span:last-child { color: var(--brand); font-size: 13px; font-weight: 700; }
.join-class-page { display: grid; place-items: start center; padding: 36px 12px; }
.join-class-card { width: min(100%, 480px); padding: 28px; border: 1px solid var(--line-soft); border-radius: 16px; background: var(--surface-1); box-shadow: 0 14px 32px rgba(15, 37, 72, .08); }
.join-class-card h1 { margin: 8px 0; }
.join-class-card p { color: var(--ink-2); line-height: 1.6; }
.join-class-card form { display: grid; gap: 10px; margin-top: 18px; }
.join-class-card .btn { justify-self: start; }
@media (max-width: 900px) { .class-hub-grid { grid-template-columns: 1fr; } }
@media (max-width: 620px) { .class-hub { padding: 14px; } .class-hub-toolbar { align-items: stretch; flex-direction: column; } .class-create { align-self: flex-start; } .class-create-form { position: static; width: 100%; margin-top: 8px; box-sizing: border-box; } }