*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #0f1117;
  --surface: #161b22;
  --surface-2: #1c2128;
  --border: rgba(255, 255, 255, 0.08);
  --text: #e6edf3;
  --muted: #7d8590;
  --faint: #444c56;
  --primary: #3fb950;
  --primary-dim: #1a3d22;
  --warning: #d29922;
  --error: #f85149;
  --blue: #58a6ff;
  --shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
  --radius: 8px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  line-height: 1.6;
  min-height: 100dvh;
}

/* ── LAYOUT ── */
.app {
  display: flex;
  min-height: 100dvh;
}

.sidebar {
  width: 220px;
  background: var(--surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  height: 100vh;
  z-index: 100;
  padding: 0;
}

.sidebar-logo {
  padding: 20px 20px 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 10px;
}

.sidebar-logo svg {
  flex-shrink: 0;
  color: var(--primary);
}

.sidebar-logo-text {
  font-weight: 700;
  font-size: 15px;
  color: var(--text);
  line-height: 1.2;
}

.sidebar-logo-sub {
  font-size: 11px;
  color: var(--muted);
  font-weight: 400;
}

.sidebar-nav {
  flex: 1;
  padding: 12px 8px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  border-radius: var(--radius);
  cursor: pointer;
  color: var(--muted);
  font-size: 13px;
  font-weight: 500;
  transition: all 150ms ease;
  border: none;
  background: none;
  width: 100%;
  text-align: left;
  text-decoration: none;
}

.nav-item:hover {
  background: var(--surface-2);
  color: var(--text);
}

.nav-item.active {
  background: var(--primary-dim);
  color: var(--primary);
}

.nav-item svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.sidebar-footer {
  padding: 12px 16px;
  border-top: 1px solid var(--border);
}

.rating-badge {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.rating-badge-label {
  font-size: 11px;
  color: var(--muted);
}

.rating-badge-value {
  font-size: 20px;
  font-weight: 700;
  color: var(--primary);
}

.main {
  margin-left: 220px;
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.topbar {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 50;
}

.topbar-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
}

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

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: all 150ms ease;
  text-decoration: none;
}

.btn-primary {
  background: var(--primary);
  color: #000;
}

.btn-primary:hover {
  filter: brightness(1.1);
}

.btn-ghost {
  background: var(--surface-2);
  color: var(--muted);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  color: var(--text);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.content {
  padding: 24px;
  flex: 1;
}

/* ── VIEWS ── */
.view {
  display: none;
}

.view.active {
  display: block;
}

/* ── KPI CARDS ── */
.kpi-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.kpi-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.kpi-label {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  margin-bottom: 8px;
}

.kpi-value {
  font-size: 28px;
  font-weight: 700;
  line-height: 1;
  margin-bottom: 6px;
}

.kpi-sub {
  font-size: 11px;
  color: var(--muted);
}

.kpi-bad {
  color: var(--error);
}

.kpi-warn {
  color: var(--warning);
}

.kpi-good {
  color: var(--primary);
}

.kpi-blue {
  color: var(--blue);
}

/* ── CHARTS ROW ── */
.charts-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 24px;
}

.chart-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.chart-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 16px;
}

.chart-container {
  position: relative;
  height: 220px;
}

/* ── TABLE ── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 16px;
}

.card-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.card-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
}

table {
  width: 100%;
  border-collapse: collapse;
}

th {
  padding: 10px 16px;
  text-align: left;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  border-bottom: 1px solid var(--border);
  background: var(--surface-2);
}

td {
  padding: 11px 16px;
  font-size: 13px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
  vertical-align: middle;
}

tr:last-child td {
  border-bottom: none;
}

tr:hover td {
  background: var(--surface-2);
  cursor: pointer;
}

/* ── BADGES ── */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 600;
}

.badge-win {
  background: rgba(63, 185, 80, 0.15);
  color: var(--primary);
}

.badge-loss {
  background: rgba(248, 81, 73, 0.15);
  color: var(--error);
}

.badge-draw {
  background: rgba(114, 160, 255, 0.15);
  color: var(--blue);
}

.badge-white {
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
}

.badge-black {
  background: rgba(0, 0, 0, 0.3);
  color: var(--muted);
  border: 1px solid var(--border);
}

/* ── MISTAKE TAGS ── */
.mtag {
  display: inline-flex;
  align-items: center;
  padding: 2px 7px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 500;
  margin: 1px;
}

.mtag-blunder {
  background: rgba(248, 81, 73, 0.15);
  color: var(--error);
}

.mtag-hanging_piece {
  background: rgba(210, 153, 34, 0.15);
  color: var(--warning);
}

.mtag-mistake {
  background: rgba(88, 166, 255, 0.15);
  color: var(--blue);
}

/* ── GAME DETAIL ── */
.game-detail-grid {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 16px;
  align-items: start;
}

.move-table td {
  font-family: monospace;
}

.move-best {
  color: var(--primary);
}

.move-excellent {
  color: #4fc3f7;
}

.move-good {
  color: var(--text);
}

.move-inaccuracy {
  color: var(--warning);
}

.move-mistake {
  color: #ff8c42;
}

.move-blunder {
  color: var(--error);
}

.hanging-row td:first-child {
  border-left: 3px solid var(--warning);
}

.critical-row td:first-child {
  border-left: 3px solid var(--error);
}

/* ── MISTAKE DETAIL PANEL ── */
.mistake-panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.mistake-item {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  cursor: pointer;
  transition: all 150ms;
}

.mistake-item:hover {
  border-color: var(--primary);
}

.mistake-item.active {
  border-color: var(--primary);
  background: var(--primary-dim);
}

.mistake-item-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 6px;
}

.eval-loss {
  font-size: 18px;
  font-weight: 700;
  color: var(--error);
}

.fen-text {
  font-family: monospace;
  font-size: 11px;
  color: var(--muted);
  word-break: break-all;
  margin-top: 6px;
}

/* ── PROGRESS ── */
.progress-bar {
  height: 6px;
  background: var(--surface-2);
  border-radius: 999px;
  overflow: hidden;
  margin-top: 6px;
}

.progress-fill {
  height: 100%;
  background: var(--primary);
  border-radius: 999px;
  transition: width 600ms ease;
}

.progress-fill.warn {
  background: var(--warning);
}

.progress-fill.bad {
  background: var(--error);
}

/* ── EMPTY STATE ── */
.empty {
  text-align: center;
  padding: 48px 24px;
  color: var(--muted);
}

.empty-icon {
  font-size: 32px;
  margin-bottom: 12px;
}

/* ── DRILL BOARD ── */
.drill-layout {
  display: grid;
  grid-template-columns: 480px 1fr;
  gap: 24px;
  align-items: start;
}

.board-wrap {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.board-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.board-title {
  font-size: 14px;
  font-weight: 600;
}

#drill-board {
  width: 440px;
  height: 440px;
  border-radius: 4px;
  overflow: hidden;
  position: relative;
  margin: 0 auto;
}

.board-grid {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  grid-template-rows: repeat(8, 1fr);
  width: 100%;
  height: 100%;
  aspect-ratio: 1;
  user-select: none;
}

.sq {
  position: relative;
  container-type: inline-size;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 100ms;
}

.sq.light {
  background: #f0d9b5;
}

.sq.dark {
  background: #b58863;
}

.sq.selected {
  background: #f6f669 !important;
  opacity: 0.8;
}

.sq.highlight {
  background: #cdd16f !important;
  opacity: 0.8;
}

.sq.hint {
  background: rgba(0, 180, 80, 0.4) !important;
}

.sq.last-from {
  background: rgba(246, 246, 105, 0.5) !important;
}

.sq.last-to {
  background: rgba(246, 246, 105, 0.7) !important;
}

.piece {
  width: 85%;
  height: 85%;
  font-size: clamp(24px, 5.2cqi, 52px);
  line-height: 1;
  text-align: center;
  pointer-events: none;
  filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.4));
}

.sq-label-file {
  position: absolute;
  bottom: 2px;
  right: 3px;
  font-size: 9px;
  font-weight: 600;
  opacity: 0.6;
  pointer-events: none;
}

.sq-label-rank {
  position: absolute;
  top: 2px;
  left: 3px;
  font-size: 9px;
  font-weight: 600;
  opacity: 0.6;
  pointer-events: none;
}

.drill-feedback {
  margin-top: 16px;
  padding: 14px 16px;
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 500;
  display: none;
}

.drill-feedback.correct {
  display: block;
  background: rgba(63, 185, 80, 0.15);
  border: 1px solid var(--primary);
  color: var(--primary);
}

.drill-feedback.wrong {
  display: block;
  background: rgba(248, 81, 73, 0.15);
  border: 1px solid var(--error);
  color: var(--error);
}

.drill-feedback.info {
  display: block;
  background: rgba(88, 166, 255, 0.1);
  border: 1px solid var(--blue);
  color: var(--blue);
}

.drill-sidebar {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.drill-info-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.drill-stat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
}

.drill-stat-row:last-child {
  border-bottom: none;
}

.drill-queue-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  max-height: 300px;
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--faint) transparent;
}

.drill-queue-item {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px 12px;
  cursor: pointer;
  font-size: 12px;
  transition: all 150ms;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.drill-queue-item:hover {
  border-color: var(--blue);
}

.drill-queue-item.current {
  border-color: var(--primary);
  background: var(--primary-dim);
}

.quality-btns {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin-top: 16px;
}

.quality-btn {
  padding: 10px 8px;
  border-radius: var(--radius);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text);
  text-align: center;
  transition: all 150ms;
}

.quality-btn:hover {
  filter: brightness(1.2);
}

.quality-btn[data-q="0"] {
  border-color: var(--error);
  color: var(--error);
}

.quality-btn[data-q="1"] {
  border-color: var(--warning);
  color: var(--warning);
}

.quality-btn[data-q="2"] {
  border-color: var(--blue);
  color: var(--blue);
}

.quality-btn[data-q="3"] {
  border-color: var(--primary);
  color: var(--primary);
}

.drill-progress-text {
  font-size: 12px;
  color: var(--muted);
  text-align: center;
  margin-top: 8px;
}

.flip-btn {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 6px 12px;
  font-size: 12px;
  color: var(--muted);
  cursor: pointer;
}

.flip-btn:hover {
  color: var(--text);
}


/* ── LOADING ── */
.skeleton {
  background: linear-gradient(90deg, var(--surface-2) 25%, var(--faint) 50%, var(--surface-2) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.4s ease-in-out infinite;
  border-radius: 4px;
}

@keyframes shimmer {
  0% {
    background-position: -200% 0;
  }

  100% {
    background-position: 200% 0;
  }
}

.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 16px;
  font-size: 13px;
  color: var(--text);
  z-index: 1000;
  box-shadow: var(--shadow);
  animation: slideIn 200ms ease;
}

@keyframes slideIn {
  from {
    transform: translateY(12px);
    opacity: 0;
  }

  to {
    transform: translateY(0);
    opacity: 1;
  }
}

/* ── BACK BUTTON ── */
.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--muted);
  cursor: pointer;
  font-size: 13px;
  margin-bottom: 16px;
  border: none;
  background: none;
  padding: 0;
}

.back-btn:hover {
  color: var(--text);
}

/* ── OPENING PILLS ── */
.opening-pill {
  display: inline-block;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 2px 7px;
  font-size: 11px;
  color: var(--muted);
}

/* ── PAGINATION ── */
.pagination {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 12px;
  justify-content: flex-end;
}

/* ── RESPONSIVE ── */
@media (max-width: 900px) {
  .sidebar {
    width: 60px;
  }

  .sidebar-logo-text,
  .sidebar-logo-sub,
  .nav-item span {
    display: none;
  }

  .main {
    margin-left: 60px;
  }

  .charts-row {
    grid-template-columns: 1fr;
  }

  .game-detail-grid {
    grid-template-columns: 1fr;
  }

  /* drill board */
  .drill-layout {
    grid-template-columns: 1fr;
  }

  #drill-board {
    width: 100%;
    height: auto;
    aspect-ratio: 1;
  }

  .piece {
    font-size: 6vw;
  }

  .chart-card[style*="grid-column"] {
    grid-column: span 1 !important;
  }
}