/* ── Variables ── */
:root {
  --bg: #080b11;
  --panel: #0f1520;
  --panel2: #141c2e;
  --border: rgba(255, 255, 255, 0.07);
  --border2: rgba(255, 255, 255, 0.11);
  --text: #cfd8ea;
  --muted: #4e6380;
  --dim: #2a3a53;
  --accent: #4a90e8;
  --accent-glow: rgba(74, 144, 232, 0.12);
  --green: #3ecf8e;
  --green-glow: rgba(62, 207, 142, 0.12);
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", Menlo, Consolas, monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --r: 10px;
  --r-sm: 6px;
}

/* ── Reset ── */
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { min-height: 100%; }

body {
  background: var(--bg);
  color: var(--text);
  font: 14px/1.5 var(--sans);
  -webkit-font-smoothing: antialiased;
}

/* ── Layout ── */
#app {
  max-width: 740px;
  margin: 0 auto;
  padding: 0 22px 60px;
}

/* ── Header ── */
header {
  padding: 30px 0 18px;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 14px;
}

.header-left h1 {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: #e0eaf8;
  line-height: 1;
}

.header-left .subtitle {
  font-size: 12px;
  color: var(--muted);
  margin-top: 5px;
  letter-spacing: 0.01em;
}

.mode-badge {
  flex-shrink: 0;
  margin-top: 3px;
  font-size: 10px;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.09em;
  background: var(--accent-glow);
  border: 1px solid rgba(74, 144, 232, 0.28);
  padding: 4px 10px;
  border-radius: 100px;
}

/* ── Viewport ── */
#viewport {
  position: relative;
  width: 100%;
  aspect-ratio: 1;
  max-height: 50vh;
  border-radius: var(--r);
  overflow: hidden;
  background: var(--panel);
  border: 1px solid var(--border2);
  box-shadow: 0 4px 32px rgba(0, 0, 0, 0.4);
}

#viewport canvas {
  width: 100%;
  height: 100%;
  display: block;
  touch-action: none;
}

.solved {
  position: absolute;
  top: 12px;
  left: 50%;
  transform: translateX(-50%);
  padding: 5px 16px;
  border-radius: 5px;
  background: rgba(62, 207, 142, 0.14);
  border: 1px solid rgba(62, 207, 142, 0.45);
  color: var(--green);
  font: 700 11px/1.2 var(--sans);
  letter-spacing: 0.09em;
  transition: opacity 0.3s;
  white-space: nowrap;
  z-index: 2;
}

.hidden { opacity: 0; pointer-events: none; }

/* ── Solved overlay (main page) ── */
.solved-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(8, 11, 17, 0.82);
  backdrop-filter: blur(6px);
  z-index: 10;
  border-radius: var(--r);
  transition: opacity 0.25s;
}

.so-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  padding: 28px 32px;
  text-align: center;
}

.so-check {
  color: var(--green);
  width: 48px;
  height: 48px;
  opacity: 0.9;
}

.so-title {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: #e0eaf8;
}

.so-stats {
  display: flex;
  gap: 24px;
  align-items: flex-start;
}

.so-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.so-stat-v {
  font: 700 22px/1 var(--mono);
  color: var(--green);
}

.so-stat-l {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--muted);
}

.so-btn {
  background: var(--green);
  color: #06120d;
  border: none;
  border-radius: var(--r-sm);
  padding: 9px 28px;
  font: 600 13px/1 var(--sans);
  cursor: pointer;
  transition: opacity 0.15s;
  margin-top: 4px;
}

.so-btn:hover  { opacity: 0.85; }
.so-btn:active { opacity: 0.7; }

/* ── Stats bar ── */
#stats-bar {
  display: flex;
  align-items: center;
  padding: 16px 0 6px;
  gap: 0;
}

.stat {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 0 20px;
}

.stat:first-child { padding-left: 0; }
.stat:last-child { padding-right: 0; }

.stat-divider {
  width: 1px;
  height: 32px;
  background: var(--border2);
  flex-shrink: 0;
}

.stat-value {
  font: 600 20px/1.1 var(--mono);
  color: #e0eaf8;
}

.stat-label {
  font-size: 10px;
  text-transform: uppercase;
  color: var(--muted);
  letter-spacing: 0.08em;
}

.chips {
  display: flex;
  gap: 4px;
  align-items: center;
  min-height: 24px;
}

.chip {
  padding: 2px 7px;
  border-radius: 4px;
  background: rgba(74, 144, 232, 0.1);
  border: 1px solid rgba(74, 144, 232, 0.22);
  font: 600 10px/1.4 var(--mono);
  color: var(--text);
}

/* ── Tabs ── */
#tabs {
  display: flex;
  border-bottom: 1px solid var(--border2);
  margin: 14px 0 0;
}

.tab {
  padding: 10px 0;
  padding-right: 28px;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--muted);
  font: 500 13px/1 var(--sans);
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
}

.tab:hover { color: var(--text); }
.tab.active { color: var(--accent); border-bottom-color: var(--accent); }

/* ── Panes ── */
.pane { padding: 18px 0 16px; }
.pane.hidden { display: none; }

.pane-desc {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.65;
  margin-bottom: 18px;
}

/* ── Info table (random stats) ── */
.info-table {
  border: 1px solid var(--border);
  border-radius: var(--r);
  overflow: hidden;
}

.info-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
  gap: 12px;
}

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

.info-row .ir-label { color: var(--muted); flex-shrink: 0; }

.info-row code {
  font: 500 12px/1 var(--mono);
  color: var(--text);
  text-align: right;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 65%;
}

/* ── Algorithm list ── */
.alg-list-header {
  display: grid;
  grid-template-columns: 1fr 52px 58px 80px;
  gap: 0 10px;
  padding: 7px 14px;
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--dim);
  border-bottom: 1px solid var(--border2);
}

.col-right { text-align: right; }

#alg-list {
  border: 1px solid var(--border);
  border-radius: var(--r);
  overflow: hidden;
  margin-bottom: 20px;
  max-height: 340px;
  overflow-y: auto;
}

#alg-list::-webkit-scrollbar { width: 4px; }
#alg-list::-webkit-scrollbar-track { background: transparent; }
#alg-list::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 2px; }

.alg-row {
  display: grid;
  grid-template-columns: 1fr 52px 58px 80px;
  gap: 0 10px;
  align-items: center;
  padding: 9px 14px;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  transition: background 0.12s;
}

.alg-row:last-child { border-bottom: none; }
.alg-row:hover { background: var(--panel2); }

.alg-row.active {
  background: var(--accent-glow);
}

.alg-name-cell {
  display: flex;
  align-items: center;
  gap: 7px;
  overflow: hidden;
}

.alg-name-text {
  font-size: 13px;
  font-weight: 500;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.alg-row.active .alg-name-text { color: #e0eaf8; }

/* Group badges */
.grp {
  flex-shrink: 0;
  font: 600 9px/1 var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 2px 6px;
  border-radius: 3px;
}

.grp-trigger { background: rgba(180, 120, 255, 0.1); color: #a070d8; border: 1px solid rgba(180, 120, 255, 0.2); }
.grp-oll     { background: rgba(74, 144, 232, 0.1);  color: #5296e0; border: 1px solid rgba(74, 144, 232, 0.2); }
.grp-pll     { background: rgba(255, 165, 60, 0.1);  color: #d88840; border: 1px solid rgba(255, 165, 60, 0.2); }
.grp-pattern { background: rgba(62, 207, 142, 0.1);  color: #38b87a; border: 1px solid rgba(62, 207, 142, 0.2); }

.alg-col-num {
  font: 500 12px/1 var(--mono);
  color: var(--muted);
  text-align: right;
}

.alg-col-reps {
  font: 600 12px/1 var(--mono);
  color: var(--text);
  text-align: right;
}

.alg-col-time {
  font: 600 12px/1 var(--mono);
  color: var(--accent);
  text-align: right;
}

/* ── Algorithm detail card ── */
#alg-detail {
  border: 1px solid var(--border);
  border-radius: var(--r);
  overflow: hidden;
  margin-bottom: 20px;
  background: var(--panel);
}

.detail-header {
  padding: 11px 16px;
  border-bottom: 1px solid var(--border);
  background: var(--panel2);
}

.detail-title {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--muted);
}

.detail-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 9px 16px;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
  gap: 14px;
}

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

.dr-label {
  color: var(--muted);
  flex-shrink: 0;
  font-size: 13px;
}

.detail-row code {
  font: 500 12px/1.3 var(--mono);
  color: var(--text);
  text-align: right;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 65%;
}

.dr-accent {
  font: 700 14px/1 var(--mono);
  color: var(--accent);
}

/* ── Embed section ── */
.embed-section {
  padding: 20px 0 0;
  border-top: 1px solid var(--border);
}

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

/* 2-column layout: controls | preview */
.embed-builder {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  align-items: start;
}

.embed-controls {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.ec-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.ec-label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--muted);
}

/* Segmented control */
.seg-ctrl {
  display: flex;
  border: 1px solid var(--border2);
  border-radius: var(--r-sm);
  overflow: hidden;
  width: fit-content;
}

.seg-btn {
  background: transparent;
  border: none;
  border-right: 1px solid var(--border2);
  color: var(--muted);
  font: 500 12px/1 var(--sans);
  padding: 6px 12px;
  cursor: pointer;
  transition: background 0.12s, color 0.12s;
  white-space: nowrap;
}

.seg-btn:last-child { border-right: none; }
.seg-btn:hover { background: var(--panel2); color: var(--text); }
.seg-btn.active {
  background: var(--accent);
  color: #fff;
}

/* Select */
.ec-select {
  background: var(--panel);
  border: 1px solid var(--border2);
  border-radius: var(--r-sm);
  color: var(--text);
  font: 500 12px/1 var(--sans);
  padding: 7px 10px;
  width: 100%;
  cursor: pointer;
  outline: none;
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6'%3E%3Cpath d='M0 0l5 6 5-6z' fill='%234e6380'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  padding-right: 28px;
}

.ec-select:focus { border-color: var(--accent); }

/* Toggle switch */
.toggle-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
}

.toggle-track {
  width: 34px;
  height: 19px;
  border-radius: 100px;
  background: var(--dim);
  position: relative;
  transition: background 0.2s;
  flex-shrink: 0;
}

.toggle-track.on { background: var(--accent); }

.toggle-thumb {
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: #fff;
  position: absolute;
  top: 3px;
  left: 3px;
  transition: transform 0.2s;
}

.toggle-track.on .toggle-thumb { transform: translateX(15px); }

.toggle-text {
  font-size: 12px;
  color: var(--text);
  user-select: none;
}

/* Dimensions inputs */
.ec-dims-group {
  display: flex;
  gap: 8px;
  align-items: center;
}

.ec-dim-field {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--muted);
}

.ec-input {
  width: 70px;
  background: var(--panel);
  border: 1px solid var(--border2);
  border-radius: var(--r-sm);
  color: var(--text);
  font: 500 12px/1 var(--mono);
  padding: 6px 8px;
  outline: none;
}

.ec-input:focus { border-color: var(--accent); }

/* Preview pane */
.embed-preview {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.embed-preview-frame {
  width: 100%;
  aspect-ratio: 1;
  border-radius: var(--r);
  overflow: hidden;
  border: 1px solid var(--border2);
  background: #000;
}

.embed-preview-frame iframe {
  width: 100%;
  height: 100%;
  border: none;
  display: block;
}

/* Code bar */
.embed-code {
  display: flex;
  align-items: stretch;
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  overflow: hidden;
}

#el-embed {
  flex: 1;
  background: var(--panel);
  padding: 10px 12px;
  font: 11px/1.55 var(--mono);
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

#btn-copy {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--panel2);
  border: none;
  border-left: 1px solid var(--border);
  color: var(--text);
  font: 500 12px/1 var(--sans);
  padding: 0 14px;
  cursor: pointer;
  transition: background 0.12s;
  white-space: nowrap;
}

#btn-copy:hover  { background: var(--accent-glow); }
#btn-copy:active { background: var(--accent); color: #fff; }
#btn-copy svg    { flex-shrink: 0; }

/* ── Footer ── */
footer {
  padding: 22px 0 0;
  border-top: 1px solid var(--border);
  margin-top: 10px;
}

.footer-title {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--dim);
  margin-bottom: 12px;
}

footer p {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.7;
  margin-bottom: 10px;
}

/* ── Responsive ── */
@media (max-width: 580px) {
  #app { padding: 0 16px 48px; }
  header { padding-top: 20px; }
  .header-left h1 { font-size: 18px; }

  #stats-bar { flex-wrap: wrap; gap: 12px; }
  .stat { padding: 0; flex: none; }
  .stat-divider { display: none; }

  .alg-list-header,
  .alg-row { grid-template-columns: 1fr 52px 58px; }
  .col-hide-xs,
  .alg-col-time { display: none; }
}

@media (max-width: 640px) {
  .embed-builder { grid-template-columns: 1fr; }
  .embed-preview { order: -1; }
}

@media (min-width: 640px) {
  #viewport { max-height: 55vh; }
}