/* ============================================================
   css·now — css.calmrocks.io
   style.css
   ============================================================ */

/* ── Fonts ─────────────────────────────────────────────────── */
/* JetBrains Mono — editor, code, monospaced labels            */
/* IBM Plex Sans  — all UI chrome                              */

/* ── Reset ─────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { height: 100%; }
body { height: 100%; font-family: 'IBM Plex Sans', system-ui, sans-serif; font-size: 13px; line-height: 1.4; overflow: hidden; }
button { font-family: inherit; cursor: pointer; }
code, pre { font-family: 'JetBrains Mono', monospace; }

/* ── Theme tokens ───────────────────────────────────────────── */
/* Each theme sets every --t-* variable on [data-theme].        */
/* The entire UI consumes only --t-* variables — never raw hex. */

[data-theme="monokai"] {
  --t-bg1:          #272822;
  --t-bg2:          #1E1F1A;
  --t-bg3:          #32332C;
  --t-bd:           #3D3E37;
  --t-bd-strong:    #5A5B52;
  --t-hover:        rgba(255,255,255,0.06);
  --t-tx1:          #F8F8F2;
  --t-tx2:          #CFCFC2;
  --t-tx3:          #908F82;
  --t-ac:           #A6E22E;
  --t-ac-dim:       rgba(166,226,46,0.15);
  --t-ac-border:    rgba(166,226,46,0.4);
  --t-ac-text:      #1A1A12;
  --t-pass:         #A6E22E;
  --t-pass-dim:     rgba(166,226,46,0.12);
  --t-pass-border:  rgba(166,226,46,0.35);
  --t-fail:         #F92672;
  --t-fail-dim:     rgba(249,38,114,0.12);
  --t-fail-border:  rgba(249,38,114,0.35);
  --t-warn:         #E6DB74;
  --t-warn-dim:     rgba(230,219,116,0.12);
  --t-warn-border:  rgba(230,219,116,0.35);
  --t-ed-sel:       #A6E22E;
  --t-ed-prop:      #66D9E8;
  --t-ed-val:       #E6DB74;
  --t-ed-num:       #AE81FF;
  --t-ed-cmt:       #BCBCB0;
  --t-ed-ln:        #5C5C52;
  --t-ed-cursor:    #F8F8F2;
  --t-ed-selection: rgba(166,226,46,0.2);
  --t-dot:          #A6E22E;
}

[data-theme="dracula"] {
  --t-bg1:          #282A36;
  --t-bg2:          #21222C;
  --t-bg3:          #343746;
  --t-bd:           #44475A;
  --t-bd-strong:    #6272A4;
  --t-hover:        rgba(255,255,255,0.06);
  --t-tx1:          #F8F8F2;
  --t-tx2:          #CFCFD0;
  --t-tx3:          #8B8FA8;
  --t-ac:           #BD93F9;
  --t-ac-dim:       rgba(189,147,249,0.15);
  --t-ac-border:    rgba(189,147,249,0.4);
  --t-ac-text:      #1A1520;
  --t-pass:         #50FA7B;
  --t-pass-dim:     rgba(80,250,123,0.12);
  --t-pass-border:  rgba(80,250,123,0.35);
  --t-fail:         #FF5555;
  --t-fail-dim:     rgba(255,85,85,0.12);
  --t-fail-border:  rgba(255,85,85,0.35);
  --t-warn:         #F1FA8C;
  --t-warn-dim:     rgba(241,250,140,0.12);
  --t-warn-border:  rgba(241,250,140,0.35);
  --t-ed-sel:       #FF79C6;
  --t-ed-prop:      #8BE9FD;
  --t-ed-val:       #F1FA8C;
  --t-ed-num:       #BD93F9;
  --t-ed-cmt:       #9CAAB8;
  --t-ed-ln:        #6272A4;
  --t-ed-cursor:    #F8F8F2;
  --t-ed-selection: rgba(189,147,249,0.2);
  --t-dot:          #BD93F9;
}

[data-theme="nord"] {
  --t-bg1:          #2E3440;
  --t-bg2:          #252932;
  --t-bg3:          #3B4252;
  --t-bd:           #3B4252;
  --t-bd-strong:    #4C566A;
  --t-hover:        rgba(255,255,255,0.05);
  --t-tx1:          #ECEFF4;
  --t-tx2:          #D8DEE9;
  --t-tx3:          #8896A8;
  --t-ac:           #88C0D0;
  --t-ac-dim:       rgba(136,192,208,0.15);
  --t-ac-border:    rgba(136,192,208,0.4);
  --t-ac-text:      #1C2330;
  --t-pass:         #A3BE8C;
  --t-pass-dim:     rgba(163,190,140,0.12);
  --t-pass-border:  rgba(163,190,140,0.35);
  --t-fail:         #BF616A;
  --t-fail-dim:     rgba(191,97,106,0.12);
  --t-fail-border:  rgba(191,97,106,0.35);
  --t-warn:         #EBCB8B;
  --t-warn-dim:     rgba(235,203,139,0.12);
  --t-warn-border:  rgba(235,203,139,0.35);
  --t-ed-sel:       #88C0D0;
  --t-ed-prop:      #81A1C1;
  --t-ed-val:       #A3BE8C;
  --t-ed-num:       #B48EAD;
  --t-ed-cmt:       #8896A8;
  --t-ed-ln:        #4C566A;
  --t-ed-cursor:    #ECEFF4;
  --t-ed-selection: rgba(136,192,208,0.2);
  --t-dot:          #88C0D0;
}

[data-theme="github"] {
  --t-bg1:          #FFFFFF;
  --t-bg2:          #F6F8FA;
  --t-bg3:          #EAEEF2;
  --t-bd:           #D0D7DE;
  --t-bd-strong:    #B0B8C0;
  --t-hover:        rgba(0,0,0,0.04);
  --t-tx1:          #1F2328;
  --t-tx2:          #3D444D;
  --t-tx3:          #636C76;
  --t-ac:           #0550AE;
  --t-ac-dim:       rgba(5,80,174,0.07);
  --t-ac-border:    rgba(5,80,174,0.3);
  --t-ac-text:      #FFFFFF;
  --t-pass:         #1A7F37;
  --t-pass-dim:     rgba(26,127,55,0.08);
  --t-pass-border:  rgba(26,127,55,0.3);
  --t-fail:         #CF222E;
  --t-fail-dim:     rgba(207,34,46,0.08);
  --t-fail-border:  rgba(207,34,46,0.3);
  --t-warn:         #7D4E00;
  --t-warn-dim:     rgba(125,78,0,0.08);
  --t-warn-border:  rgba(125,78,0,0.3);
  --t-ed-sel:       #116329;
  --t-ed-prop:      #0550AE;
  --t-ed-val:       #0A3069;
  --t-ed-num:       #6E40C9;
  --t-ed-cmt:       #636C76;
  --t-ed-ln:        #9EA8B3;
  --t-ed-cursor:    #1F2328;
  --t-ed-selection: rgba(5,80,174,0.12);
  --t-dot:          #0550AE;
}

/* ── App shell ──────────────────────────────────────────────── */
.app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  background: var(--t-bg1);
  color: var(--t-tx1);
  transition: background 0.2s, color 0.2s;
}

/* ── Topbar ─────────────────────────────────────────────────── */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 40px;
  border-bottom: 1px solid var(--t-bd);
  background: var(--t-bg2);
  flex-shrink: 0;
  padding-right: 12px;
}

.topbar-left {
  display: flex;
  align-items: center;
  height: 100%;
}

.topbar-right {
  display: flex;
  align-items: center;
  height: 100%;
  gap: 0;
}

/* Logo */
.logo {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: -0.4px;
  color: var(--t-tx1);
  padding: 0 18px;
  border-right: 1px solid var(--t-bd);
  height: 100%;
  display: flex;
  align-items: center;
  gap: 0;
  user-select: none;
}

.logo-dot {
  color: var(--t-ac);
  transition: color 0.2s;
}

/* Mode tabs */
.mode-tabs {
  display: flex;
  height: 100%;
}

.mode-tab {
  display: flex;
  align-items: center;
  padding: 0 16px;
  font-size: 12px;
  font-weight: 400;
  color: var(--t-tx2);
  background: transparent;
  border: none;
  border-right: 1px solid var(--t-bd);
  border-bottom: 2px solid transparent;
  position: relative;
  top: 1px;
  transition: color 0.15s, border-color 0.15s, background 0.15s;
  height: calc(100% + 1px);
}

.mode-tab:hover {
  color: var(--t-tx1);
  background: var(--t-hover);
}

.mode-tab.active {
  color: var(--t-tx1);
  font-weight: 500;
  border-bottom-color: var(--t-ac);
  background: var(--t-bg1);
}

/* Theme picker */
.theme-picker {
  display: flex;
  align-items: center;
  height: 100%;
  border-left: 1px solid var(--t-bd);
  padding: 0 4px;
  gap: 2px;
}

.theme-btn {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 4px 9px;
  border-radius: 3px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--t-tx3);
  font-size: 11px;
  font-family: 'JetBrains Mono', monospace;
  transition: color 0.15s, background 0.15s, border-color 0.15s;
}

.theme-btn:hover {
  color: var(--t-tx2);
  background: var(--t-hover);
}

.theme-btn.active {
  color: var(--t-tx1);
  background: var(--t-ac-dim);
  border-color: var(--t-ac-border);
}

.theme-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--t-dot);
  flex-shrink: 0;
  transition: background 0.2s;
}

/* Topbar buttons */
.tb-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 0 14px;
  height: 100%;
  border: none;
  border-left: 1px solid var(--t-bd);
  background: transparent;
  color: var(--t-tx2);
  font-size: 12px;
  transition: color 0.15s, background 0.15s;
}

.tb-btn:hover {
  color: var(--t-tx1);
  background: var(--t-hover);
}

/* ── Views ──────────────────────────────────────────────────── */
.view {
  display: none;
  flex: 1;
  min-height: 0;
  overflow: hidden;
}

.view.active {
  display: flex;
}

/* ── Sidebar ────────────────────────────────────────────────── */
.sidebar {
  width: 210px;
  flex-shrink: 0;
  border-right: 1px solid var(--t-bd);
  background: var(--t-bg2);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.sidebar-block {
  padding: 14px 12px 12px;
  border-bottom: 1px solid var(--t-bd);
}

.sidebar-block--grow {
  flex: 1;
  overflow-y: auto;
  border-bottom: none;
}

.sidebar-label {
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.7px;
  text-transform: uppercase;
  color: var(--t-tx3);
  margin-bottom: 9px;
}

/* Topic rows */
.topic-list {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.topic-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px 8px;
  border-radius: 3px;
  border: none;
  background: transparent;
  color: var(--t-tx2);
  text-align: left;
  width: 100%;
  transition: background 0.12s, color 0.12s;
}

.topic-row:hover {
  background: var(--t-hover);
  color: var(--t-tx1);
}

.topic-row.active {
  background: var(--t-ac-dim);
  color: var(--t-ac);
}

.topic-left {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 12px;
}

.topic-icon {
  flex-shrink: 0;
  opacity: 0.7;
}

.topic-row.active .topic-icon {
  opacity: 1;
}

.topic-count {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--t-tx3);
}

.topic-row.active .topic-count {
  color: var(--t-ac);
  font-weight: 500;
}

/* Progress */
.progress-track {
  height: 2px;
  background: var(--t-bd);
  border-radius: 1px;
  margin-top: 12px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--t-ac);
  border-radius: 1px;
  transition: width 0.3s ease, background 0.2s;
}

.progress-meta {
  display: flex;
  justify-content: space-between;
  margin-top: 6px;
}

.progress-meta span {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--t-tx3);
}

/* Challenge list */
.challenge-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-top: 4px;
}

.challenge-row {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 7px 8px;
  border-radius: 3px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s;
}

.challenge-row:hover:not(.locked) {
  background: var(--t-hover);
}

.challenge-row.active {
  background: var(--t-bg1);
  border-color: var(--t-bd);
}

.challenge-row.locked {
  opacity: 0.55;
  cursor: default;
}

.challenge-status {
  width: 18px;
  height: 18px;
  border-radius: 2px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.challenge-row.done .challenge-status {
  background: var(--t-pass-dim);
  color: var(--t-pass);
  border: 1px solid var(--t-pass-border);
}

.challenge-row.active .challenge-status {
  background: var(--t-ac-dim);
  color: var(--t-ac);
  border: 1px solid var(--t-ac-border);
}

.challenge-row.locked .challenge-status {
  background: var(--t-bg3);
  color: var(--t-tx3);
  border: 1px solid var(--t-bd);
}

.challenge-meta {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.challenge-name {
  font-size: 12px;
  color: var(--t-tx1);
  font-family: 'JetBrains Mono', monospace;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.challenge-row.active .challenge-name {
  font-weight: 500;
}

.challenge-hint {
  font-size: 11px;
  color: var(--t-tx3);
}

/* Difficulty badges */
.diff-badge {
  font-size: 10px;
  font-family: 'JetBrains Mono', monospace;
  font-weight: 500;
  padding: 2px 6px;
  border-radius: 2px;
  flex-shrink: 0;
}

.diff-easy {
  background: var(--t-pass-dim);
  color: var(--t-pass);
  border: 1px solid var(--t-pass-border);
}

.diff-med {
  background: var(--t-warn-dim);
  color: var(--t-warn);
  border: 1px solid var(--t-warn-border);
}

.diff-hard {
  background: var(--t-fail-dim);
  color: var(--t-fail);
  border: 1px solid var(--t-fail-border);
}

/* ── Challenge main ─────────────────────────────────────────── */
.challenge-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  overflow: hidden;
}

.challenge-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--t-bd);
  background: var(--t-bg1);
  flex-shrink: 0;
}

.challenge-title {
  font-size: 13px;
  font-weight: 500;
  color: var(--t-tx1);
  line-height: 1.3;
}

.challenge-desc {
  font-size: 12px;
  color: var(--t-tx2);
  margin-top: 4px;
  line-height: 1.55;
}

.challenge-desc code {
  font-size: 11px;
  background: var(--t-bg3);
  padding: 1px 5px;
  border-radius: 2px;
  border: 1px solid var(--t-bd);
  color: var(--t-tx1);
}

.challenge-actions {
  display: flex;
  gap: 6px;
  flex-shrink: 0;
  align-items: flex-start;
}

/* Action buttons */
.action-btn {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 5px 11px;
  border: 1px solid var(--t-bd);
  border-radius: 3px;
  background: var(--t-bg2);
  color: var(--t-tx2);
  font-size: 12px;
  white-space: nowrap;
  transition: color 0.12s, background 0.12s, border-color 0.12s;
}

.action-btn:hover {
  color: var(--t-tx1);
  background: var(--t-hover);
}

.action-btn--primary {
  background: var(--t-ac-dim);
  border-color: var(--t-ac-border);
  color: var(--t-ac);
  font-weight: 500;
}

.action-btn--primary:hover {
  background: var(--t-ac-dim);
  opacity: 0.85;
}

.action-btn--icon {
  padding: 4px 8px;
}

/* ── Editor split ───────────────────────────────────────────── */
.editor-split {
  display: flex;
  flex: 1;
  min-height: 0;
}

.editor-pane {
  flex: 1;
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--t-bd);
  min-width: 0;
}

.pane-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 12px;
  height: 30px;
  background: var(--t-bg2);
  border-bottom: 1px solid var(--t-bd);
  flex-shrink: 0;
}

.pane-lang {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.6px;
  text-transform: uppercase;
  color: var(--t-ac);
}

.pane-lang--html {
  color: var(--t-ed-sel);
}

.pane-filename {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--t-tx3);
}

.editor-body {
  flex: 1;
  overflow: hidden;
  background: var(--t-bg1);
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
}

/* ── Resize handle ──────────────────────────────────────────── */
.resize-handle {
  width: 4px;
  background: var(--t-bd);
  cursor: col-resize;
  flex-shrink: 0;
  transition: background 0.15s;
}
.resize-handle:hover,
.resize-handle.dragging {
  background: var(--t-ac);
}

/* ── Preview column (challenges) ────────────────────────────── */
.preview-col {
  width: 280px;
  min-width: 160px;
  max-width: 50%;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
}

.preview-half {
  flex: 1;
  display: flex;
  flex-direction: column;
  border-bottom: 1px solid var(--t-bd);
}

.preview-half:last-child {
  border-bottom: none;
}

.preview-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 10px;
  height: 30px;
  background: var(--t-bg2);
  border-bottom: 1px solid var(--t-bd);
  flex-shrink: 0;
}

.preview-label {
  font-size: 11px;
  font-weight: 500;
  color: var(--t-tx2);
}

.preview-tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  font-weight: 500;
  padding: 2px 6px;
  border-radius: 2px;
}

.preview-tag--goal {
  background: var(--t-bg3);
  color: var(--t-tx3);
  border: 1px solid var(--t-bd);
}

.preview-tag--live {
  background: var(--t-ac-dim);
  color: var(--t-ac);
  border: 1px solid var(--t-ac-border);
}

.preview-body {
  flex: 1;
  background: var(--t-bg1);
  overflow: hidden;
}

/* ── Check row ──────────────────────────────────────────────── */
.checks-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 14px;
  height: 32px;
  background: var(--t-bg2);
  border-top: 1px solid var(--t-bd);
  flex-shrink: 0;
}

.checks-label {
  font-size: 11px;
  color: var(--t-tx3);
  margin-right: 2px;
}

.check-item {
  display: flex;
  align-items: center;
  gap: 4px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  font-weight: 500;
}

.check-pass { color: var(--t-pass); }
.check-fail { color: var(--t-fail); }

/* ── Reference drawer ───────────────────────────────────────── */
.ref-drawer {
  border-top: 1px solid var(--t-bd);
  background: var(--t-bg2);
  flex-shrink: 0;
}

.ref-drawer-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  height: 33px;
  width: 100%;
  border: none;
  background: transparent;
  color: var(--t-tx2);
  cursor: pointer;
  transition: background 0.12s;
}

.ref-drawer-bar:hover {
  background: var(--t-hover);
}

.ref-drawer-title {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 12px;
  font-weight: 500;
  color: var(--t-tx2);
}

.ref-drawer-toggle-label {
  font-size: 11px;
  color: var(--t-tx3);
}

.ref-drawer-body {
  display: flex;
  border-top: 1px solid var(--t-bd);
  max-height: 220px;
}

.ref-drawer-body[hidden] { display: none; }

.ref-nav {
  width: 148px;
  flex-shrink: 0;
  border-right: 1px solid var(--t-bd);
  padding: 6px 0;
  overflow-y: auto;
  background: var(--t-bg1);
}

.ref-nav-item {
  display: block;
  width: 100%;
  padding: 6px 12px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--t-tx2);
  background: transparent;
  border: none;
  border-left: 2px solid transparent;
  text-align: left;
  cursor: pointer;
  transition: background 0.12s, color 0.12s, border-color 0.12s;
}

.ref-nav-item:hover {
  background: var(--t-hover);
  color: var(--t-tx1);
}

.ref-nav-item.active {
  color: var(--t-ac);
  border-left-color: var(--t-ac);
  background: var(--t-ac-dim);
  font-weight: 500;
}

.ref-detail {
  flex: 1;
  padding: 13px 16px;
  overflow-y: auto;
  background: var(--t-bg1);
}

.ref-prop-name {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  font-weight: 500;
  color: var(--t-tx1);
  margin-bottom: 5px;
}

.ref-prop-desc {
  font-size: 12px;
  color: var(--t-tx2);
  line-height: 1.6;
  margin-bottom: 10px;
}

.ref-prop-desc strong {
  color: var(--t-tx1);
  font-weight: 500;
}

.ref-prop-desc code {
  font-size: 11px;
  background: var(--t-bg3);
  padding: 1px 4px;
  border-radius: 2px;
  border: 1px solid var(--t-bd);
  color: var(--t-tx1);
}

.ref-values {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-bottom: 10px;
}

.ref-value-pill {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  padding: 3px 8px;
  border-radius: 2px;
  border: 1px solid var(--t-bd);
  background: var(--t-bg2);
  color: var(--t-tx2);
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s, color 0.12s;
}

.ref-value-pill:hover {
  background: var(--t-hover);
  color: var(--t-tx1);
}

.ref-value-pill.active {
  background: var(--t-ac-dim);
  border-color: var(--t-ac-border);
  color: var(--t-ac);
  font-weight: 500;
}

/* Reference mini preview */
.ref-mini-preview {
  background: var(--t-bg2);
  border: 1px solid var(--t-bd);
  border-radius: 2px;
  padding: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 46px;
  margin-bottom: 10px;
}

.ref-flex-demo {
  display: flex;
  justify-content: center;
  gap: 4px;
  width: 100%;
}

.ref-box {
  width: 22px;
  height: 22px;
  border-radius: 2px;
  border: 1px solid var(--t-bd);
  background: var(--t-bg3);
  color: var(--t-tx2);
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  font-weight: 500;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Definition tag + panel */
.def-tag {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  font-weight: 500;
  padding: 3px 9px;
  border-radius: 2px;
  background: var(--t-ac-dim);
  color: var(--t-ac);
  border: 1px solid var(--t-ac-border);
  cursor: pointer;
  transition: opacity 0.12s;
}

.def-tag:hover { opacity: 0.8; }

.def-panel {
  background: var(--t-bg2);
  border: 1px solid var(--t-bd);
  border-radius: 3px;
  padding: 12px 14px;
  margin-top: 8px;
}

.def-panel[hidden] { display: none; }

.def-term {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  font-weight: 500;
  color: var(--t-tx1);
  margin-bottom: 5px;
}

.def-body {
  font-size: 12px;
  color: var(--t-tx2);
  line-height: 1.6;
}

.def-body code {
  font-size: 11px;
  background: var(--t-bg1);
  padding: 1px 4px;
  border-radius: 2px;
  border: 1px solid var(--t-bd);
  color: var(--t-tx1);
}

.def-example {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  background: var(--t-bg1);
  border: 1px solid var(--t-bd);
  border-radius: 2px;
  padding: 8px 10px;
  margin-top: 8px;
  color: var(--t-tx2);
  line-height: 1.7;
  white-space: pre;
}

/* ── Sandbox main ───────────────────────────────────────────── */
.sandbox-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  overflow: hidden;
}

.sandbox-editors {
  display: flex;
  flex: 1;
  min-height: 0;
}

.sandbox-preview-col {
  width: 280px;
  min-width: 160px;
  max-width: 50%;
  flex-shrink: 0;
  border-left: 1px solid var(--t-bd);
  display: flex;
  flex-direction: column;
}

.sandbox-preview-body {
  flex: 1;
  background: var(--t-bg1);
  overflow: hidden;
}

.share-strip {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 10px;
  border-top: 1px solid var(--t-bd);
  background: var(--t-bg2);
}

.share-url {
  flex: 1;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  padding: 4px 7px;
  border: 1px solid var(--t-bd);
  border-radius: 2px;
  background: var(--t-bg1);
  color: var(--t-tx2);
  outline: none;
}

/* ── Scrollbar styling ──────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--t-bd); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--t-bd-strong); }

/* ── Utility ────────────────────────────────────────────────── */
[hidden] { display: none !important; }

/* ── Challenge success banner ───────────────────────────────── */
.success-banner {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
  padding: 5px 12px;
  border-radius: 3px;
  background: var(--t-pass-dim);
  color: var(--t-pass);
  border: 1px solid var(--t-pass-border);
  font-size: 12px;
  font-weight: 500;
  animation: fadeInOut 3s ease forwards;
}

@keyframes fadeInOut {
  0%   { opacity: 0; transform: translateY(-4px); }
  15%  { opacity: 1; transform: translateY(0); }
  75%  { opacity: 1; }
  100% { opacity: 0; }
}

/* ── Reference mini code block ──────────────────────────────── */
.ref-mini-code {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  background: var(--t-bg2);
  border: 1px solid var(--t-bd);
  border-radius: 2px;
  padding: 8px 10px;
  margin-bottom: 10px;
  color: var(--t-tx2);
  white-space: pre;
  overflow-x: auto;
  line-height: 1.7;
}

/* ── MDN link ───────────────────────────────────────────────── */
.ref-mdn-link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 11px;
  color: var(--t-ac);
  text-decoration: none;
  margin-bottom: 10px;
  opacity: 0.8;
  transition: opacity 0.15s;
}

.ref-mdn-link:hover { opacity: 1; text-decoration: underline; }

/* ── Snippet management ─────────────────────────────────────── */
.snippet-row {
  display: flex;
  align-items: center;
  width: 100%;
}

.snippet-delete-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 2px;
  flex-shrink: 0;
  color: var(--t-tx3);
  opacity: 0;
  transition: opacity 0.15s, background 0.15s, color 0.15s;
  cursor: pointer;
}

.snippet-row:hover .snippet-delete-btn { opacity: 1; }
.snippet-delete-btn:hover { background: var(--t-fail-dim); color: var(--t-fail); }

/* ── Export row ─────────────────────────────────────────────── */
.snippet-export-row {
  display: flex;
  gap: 4px;
  padding: 8px 8px 4px;
  border-top: 1px solid var(--t-bd);
  margin-top: 4px;
}

.export-btn {
  display: flex;
  align-items: center;
  gap: 5px;
  flex: 1;
  padding: 5px 8px;
  border: 1px solid var(--t-bd);
  border-radius: 3px;
  background: var(--t-bg1);
  color: var(--t-tx2);
  font-size: 11px;
  font-family: 'IBM Plex Sans', system-ui, sans-serif;
  cursor: pointer;
  justify-content: center;
  transition: background 0.12s, color 0.12s, border-color 0.12s;
}

.export-btn:hover {
  background: var(--t-ac-dim);
  border-color: var(--t-ac-border);
  color: var(--t-ac);
}

/* ── Welcome modal ──────────────────────────────────────────── */
/* Modal uses fixed light colours — never inherits theme tokens  */
:root {
  --modal-bg:      #FFFFFF;
  --modal-bg2:     #F6F8FA;
  --modal-bd:      #D0D7DE;
  --modal-tx1:     #1F2328;
  --modal-tx2:     #3D444D;
  --modal-tx3:     #636C76;
  --modal-ac:      #C94428;
  --modal-ac-dim:  rgba(201,68,40,0.08);
  --modal-ac-bd:   rgba(201,68,40,0.25);
  --modal-hover:   rgba(0,0,0,0.04);
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: 20px;
  animation: backdropIn 0.2s ease;
}

.modal-backdrop.hidden { display: none; }

@keyframes backdropIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

.modal {
  background: var(--modal-bg);
  border: 1px solid var(--modal-bd);
  border-radius: 6px;
  width: 100%;
  max-width: 480px;
  overflow: hidden;
  animation: modalIn 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.35);
}

@keyframes modalIn {
  from { opacity: 0; transform: translateY(12px) scale(0.98); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--modal-bd);
  background: var(--modal-bg2);
}

.modal-logo {
  font-family: 'JetBrains Mono', monospace;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: -0.4px;
  color: var(--modal-tx1);
}

.modal-logo-dot { color: var(--modal-ac); }

.modal-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border: 1px solid var(--modal-bd);
  border-radius: 3px;
  background: transparent;
  color: var(--modal-tx3);
  cursor: pointer;
  transition: background 0.12s, color 0.12s;
}

.modal-close:hover {
  background: var(--modal-hover);
  color: var(--modal-tx1);
}

.modal-body { padding: 24px 24px 20px; }

.modal-title {
  font-size: 22px;
  font-weight: 500;
  color: var(--modal-tx1);
  line-height: 1.2;
  margin-bottom: 10px;
  letter-spacing: -0.3px;
}

.modal-desc {
  font-size: 13px;
  color: var(--modal-tx2);
  line-height: 1.65;
  margin-bottom: 22px;
}

.modal-features {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.modal-feature {
  display: flex;
  align-items: flex-start;
  gap: 14px;
}

.modal-feature-icon {
  width: 34px;
  height: 34px;
  border-radius: 4px;
  background: var(--modal-ac-dim);
  border: 1px solid var(--modal-ac-bd);
  color: var(--modal-ac);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.modal-feature-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-top: 2px;
}

.modal-feature-text strong {
  font-size: 13px;
  font-weight: 500;
  color: var(--modal-tx1);
}

.modal-feature-text span {
  font-size: 12px;
  color: var(--modal-tx2);
  line-height: 1.55;
}

.modal-footer {
  padding: 16px 24px 20px;
  border-top: 1px solid var(--modal-bd);
  background: var(--modal-bg2);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.modal-footer-note {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  color: var(--modal-tx3);
  margin-bottom: 4px;
}

.modal-cta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 10px 20px;
  border-radius: 4px;
  border: none;
  background: var(--modal-ac);
  color: #FFFFFF;
  font-size: 13px;
  font-weight: 500;
  font-family: 'IBM Plex Sans', system-ui, sans-serif;
  cursor: pointer;
  transition: opacity 0.15s;
  width: 100%;
}

.modal-cta:hover { opacity: 0.88; }

.modal-secondary {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 8px 20px;
  border-radius: 4px;
  border: 1px solid var(--modal-bd);
  background: transparent;
  color: var(--modal-tx2);
  font-size: 12px;
  font-family: 'IBM Plex Sans', system-ui, sans-serif;
  cursor: pointer;
  transition: background 0.12s, color 0.12s;
  width: 100%;
}

.modal-secondary:hover {
  background: var(--modal-hover);
  color: var(--modal-tx1);
}

/* ── Share button (topbar, sandbox only) ────────────────────── */
.tb-btn.share-copied {
  color: var(--t-pass);
  border-left-color: var(--t-pass-border);
}