:root {
  font-family:
    Inter,
    ui-sans-serif,
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  font-synthesis: none;
  color-scheme: dark;
  --bg: #111718;
  --sidebar: #101414;
  --panel: #1b2222;
  --panel-soft: #202828;
  --line: #323d3d;
  --text: #ebeae3;
  --muted: #9aa8a4;
  --accent: #adbaaa;
  --accent-deep: #31483f;
  --gold: #d1ae83;
  --danger: #d28f7f;
  --board-light: #c9c7b7;
  --board-dark: #738880;
}
body[data-theme="light"] {
  color-scheme: light;
  --bg: #f0eee8;
  --sidebar: #e9e5dc;
  --panel: #fffdfa;
  --panel-soft: #efede6;
  --line: #d8d5cc;
  --text: #252b2b;
  --muted: #5d6866;
  --accent: #485f53;
  --accent-deep: #d2dfd2;
  --gold: #866546;
  --danger: #a6493c;
}
* {
  box-sizing: border-box;
}
html {
  min-width: 280px;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  line-height: 1.55;
}
button,
input,
select {
  font: inherit;
}
button {
  cursor: pointer;
}
button:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}
button:focus-visible,
input:focus-visible,
select:focus-visible,
a:focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 3px;
}
a {
  color: var(--accent);
}
.sr-only {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  min-height: 0 !important;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.app-shell {
  display: flex;
  min-height: 100vh;
}
.navigation {
  position: sticky;
  top: 0;
  left: 0;
  align-self: flex-start;
  display: flex;
  flex-direction: column;
  width: 252px;
  height: 100vh;
  min-width: 252px;
  background: var(--sidebar);
  border-right: 1px solid var(--line);
  padding: 32px 20px 24px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 5px 58px;
}
.brand-symbol {
  height: 42px;
  width: 42px;
  border: 1px solid #8e9e92;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-size: 27px;
  color: var(--gold);
  background: #202b29;
}
.brand-title {
  font-size: 17px;
  letter-spacing: 0.15em;
  font-weight: 650;
}
.brand-subtitle {
  font-size: 9px;
  letter-spacing: 0.2em;
  color: var(--muted);
  margin-top: 1px;
}
.nav-caption,
.overline {
  display: block;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--muted);
  text-transform: uppercase;
}
.nav-caption {
  margin: 0 12px 18px;
}
.navigation nav {
  display: flex;
  flex-direction: column;
  gap: 7px;
}
.nav-link {
  display: flex;
  align-items: center;
  gap: 15px;
  text-align: left;
  background: none;
  border: 1px solid transparent;
  color: var(--muted);
  border-radius: 9px;
  padding: 12px 14px;
  width: 100%;
  transition:
    background 0.2s,
    color 0.2s;
  white-space: nowrap;
  font-size: 13px;
}
.nav-link:hover {
  background: var(--panel-soft);
  color: var(--text);
}
.nav-link.active {
  background: #2a3835;
  border-color: #415249;
  color: #edf2e9;
}
.nav-glyph {
  font-size: 21px;
  font-family: Georgia, serif;
  width: 23px;
  text-align: center;
  color: var(--gold);
}
.nav-bottom {
  margin-top: auto;
  padding: 22px 14px 8px;
  border-top: 1px solid var(--line);
}
.practice-line {
  color: var(--gold);
  font-family: Georgia, serif;
  letter-spacing: 0.16em;
  margin-bottom: 8px;
}
.nav-bottom small {
  line-height: 1.7;
  color: var(--muted);
}
.main-content {
  flex: 1;
  min-width: 0;
  padding: 52px clamp(20px, 4vw, 74px) 70px;
  max-width: 1610px;
  margin: 0 auto;
  width: 100%;
}
.workspace-heading {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 20px;
  margin-bottom: 36px;
}
.workspace-heading .overline {
  color: var(--gold);
  margin-bottom: 12px;
}
.workspace-heading h1 {
  font-size: clamp(34px, 3.8vw, 55px);
  line-height: 1.07;
  font-family: Georgia, "Times New Roman", serif;
  font-weight: 400;
  letter-spacing: -0.045em;
  margin: 0 0 12px;
}
.workspace-heading p {
  color: var(--muted);
  margin: 0;
  font-size: 14px;
}
.current-mode {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--muted);
  white-space: nowrap;
  margin-top: 16px;
}
.status-dot {
  display: inline-block;
  width: 7px;
  height: 7px;
  background: #9cb8a4;
  border-radius: 50%;
  box-shadow: 0 0 0 4px #9cb8a419;
}
.workspace-grid {
  display: grid;
  grid-template-columns: minmax(300px, 1.25fr) minmax(312px, 0.93fr);
  gap: 28px;
  align-items: start;
}
.board-column {
  min-width: 0;
}
.board-topline {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  text-transform: uppercase;
  letter-spacing: 0.13em;
  font-weight: 650;
  font-size: 10px;
  color: var(--muted);
  padding: 0 1px 12px;
}
.board-mount {
  aspect-ratio: 1;
  position: relative;
  width: 100%;
  background: var(--board-light);
  border: 10px solid #2b3836;
  box-shadow: 0 24px 60px #0002;
  overflow: hidden;
}
.board-grid {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  grid-template-rows: repeat(8, 1fr);
  height: 100%;
  width: 100%;
}
.square {
  position: relative;
  border: 0;
  border-radius: 0;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 0;
  min-height: 0;
  transition: background-color 0.12s;
  touch-action: manipulation;
}
.square.light {
  background: var(--board-light);
  color: #465249;
}
.square.dark-square {
  background: var(--board-dark);
  color: #f3f4e9;
}
.square:hover {
  filter: brightness(1.06);
  z-index: 1;
}
.square.selected {
  box-shadow: inset 0 0 0 4px #d8ac59;
  z-index: 1;
}
.square.recent {
  background-image: linear-gradient(#f5db744a, #f5db744a);
}
.square.legal-target:after {
  content: "";
  position: absolute;
  width: 27%;
  aspect-ratio: 1;
  background: #2c544c88;
  border-radius: 50%;
  pointer-events: none;
}
.square.target {
  box-shadow: inset 0 0 0 3px #b9875e;
}
.square.path-square {
  background-image: linear-gradient(#f8e3a188, #f8e3a188);
}
.piece {
  display: block;
  font-family: "Segoe UI Symbol", "Apple Symbols", "DejaVu Sans", serif;
  font-size: clamp(23px, 4.4vw, 63px);
  line-height: 1;
  z-index: 2;
  cursor: inherit;
  text-shadow: 0 2px 2px #0004;
  user-select: none;
}
.piece.white-piece {
  color: #f6f4e9;
  -webkit-text-stroke: 1.2px #29352f;
  filter: drop-shadow(1px 2px 1px #252f2b77);
}
.piece.black-piece {
  color: #263431;
  -webkit-text-stroke: 0.65px #e1e7de;
  filter: drop-shadow(1px 2px 1px #101a1777);
}
.piece.ghost {
  opacity: 0.25;
}
.piece.disc {
  font-size: clamp(25px, 3.7vw, 49px);
  color: #8b9288;
  text-shadow: none;
  -webkit-text-stroke: 0;
}
.rank-label,
.file-label {
  position: absolute;
  z-index: 3;
  font-size: clamp(8px, 1vw, 12px);
  font-weight: 750;
  opacity: 0.6;
  line-height: 1;
}
.rank-label {
  top: 5px;
  left: 5px;
}
.file-label {
  bottom: 4px;
  right: 5px;
}
.board-arrow {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}
.board-note,
.board-footer {
  font-size: 12px;
  color: var(--muted);
  line-height: 1.65;
}
.board-note {
  margin-top: 12px;
}
.board-footer {
  margin-top: 20px;
  max-width: 530px;
  border-left: 2px solid var(--line);
  padding-left: 15px;
}
.side-column {
  min-width: 0;
}
.panel {
  padding: 28px 29px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 11px;
  box-shadow: 0 10px 26px #0508090c;
}
.panel .overline {
  color: var(--gold);
  margin-bottom: 9px;
}
.panel h2 {
  font-family: Georgia, serif;
  font-size: 26px;
  line-height: 1.22;
  font-weight: 400;
  letter-spacing: -0.028em;
  margin: 0 0 24px;
}
.panel h3 {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.02em;
  margin: 0 0 10px;
}
.panel p {
  margin: 0 0 16px;
  color: var(--muted);
}
.panel b {
  color: var(--text);
}
.field-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin: 15px 0;
}
.field-row label {
  color: var(--muted);
  flex-shrink: 0;
}
.field-row select,
.field-row input {
  min-width: 80px;
  max-width: 220px;
  flex: 1;
}
input:not([type="checkbox"]),
select {
  background: var(--panel-soft);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 7px;
  padding: 10px 11px;
  width: 100%;
  outline: none;
}
input::placeholder {
  color: var(--muted);
  opacity: 0.85;
}
.check-line {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 20px 0;
  color: var(--muted);
  cursor: pointer;
}
.check-line input {
  accent-color: #7da58a;
  width: 16px;
  height: 16px;
}
.btn {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 7px;
  padding: 10px 14px;
  font-size: 12px;
  font-weight: 650;
  min-height: 39px;
  display: inline-flex;
  justify-content: center;
  align-items: center;
  line-height: 1.1;
  white-space: nowrap;
}
.btn:hover {
  background: var(--panel-soft);
}
.btn.primary {
  background: var(--accent);
  color: #14211c;
  border-color: var(--accent);
}
.btn.primary:hover {
  filter: brightness(1.1);
}
body[data-theme="light"] .btn.primary {
  color: white;
}
.btn.danger {
  border-color: #9e5a53;
  color: var(--danger);
}
.btn.current {
  background: var(--accent-deep);
  border-color: var(--accent);
  color: var(--text);
}
.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
  margin: 16px 0;
}
.segment {
  display: flex;
  gap: 6px;
  padding: 4px;
  background: var(--panel-soft);
  border-radius: 8px;
  margin: 18px 0;
}
.segment .btn {
  flex: 1;
}
.section-rule {
  border-top: 1px solid var(--line);
  margin: 24px 0;
}
.inline-form {
  display: flex;
  gap: 8px;
  margin: 11px 0;
}
.inline-form input {
  min-width: 0;
  flex: 1;
}
.helper {
  font-size: 12px !important;
  color: var(--muted) !important;
  line-height: 1.6;
}
.coach-box,
.opening-note {
  padding: 14px 16px !important;
  background: var(--panel-soft);
  border-left: 2px solid var(--accent);
  border-radius: 0 6px 6px 0;
  line-height: 1.55;
  color: var(--text) !important;
  font-size: 12px;
}
.opening-note b {
  display: block;
  margin: 12px 0 5px;
}
.opening-note b:first-child {
  margin-top: 0;
}
.opening-note p {
  margin-bottom: 7px;
}
.move-history {
  max-height: 190px;
  overflow: auto;
  display: flex;
  gap: 5px;
  flex-wrap: wrap;
  align-content: flex-start;
}
.move-chip {
  border: 0;
  border-radius: 4px;
  background: transparent;
  color: var(--muted);
  padding: 4px 6px;
  font-size: 12px;
}
.move-chip:hover,
.move-chip.selected-chip {
  background: var(--accent-deep);
  color: var(--text);
}
.result-line {
  font-weight: 700;
  color: var(--gold) !important;
}
.muted {
  color: var(--muted);
}
.progress-track {
  height: 7px;
  border-radius: 20px;
  background: var(--line);
  overflow: hidden;
  margin-top: 14px;
}
.progress-track > div {
  background: var(--accent);
  height: 100%;
  border-radius: inherit;
  transition: width 0.2s;
}
.subtabs {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-bottom: 21px;
}
.subtab {
  border-radius: 30px;
  background: none;
  color: var(--muted);
  border: 1px solid var(--line);
  padding: 8px 13px;
  font-size: 11px;
  font-weight: 700;
}
.subtab.active {
  background: var(--accent-deep);
  color: var(--text);
  border-color: #536b5e;
}
.mental-surface {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  min-height: 440px;
  aspect-ratio: 1;
  background: radial-gradient(circle at center, #263330 0%, #161e1d 74%);
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 40px 25px;
}
.mental-icon {
  color: var(--gold);
  font-size: 45px;
  font-family: Georgia, serif;
  margin-bottom: 25px;
}
.mental-surface h2 {
  font-family: Georgia, serif;
  font-size: clamp(45px, 7vw, 80px);
  letter-spacing: -0.05em;
  font-weight: 400;
  margin: 15px 0 9px;
  color: #f3f1e8;
}
.mental-surface p {
  color: #afbab4;
  max-width: 310px;
}
.mental-surface .center {
  justify-content: center;
}
.mental-result {
  min-height: 42px;
}
.target-panel {
  text-align: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 18px;
  margin: 22px 0 10px;
  background: var(--panel-soft);
}
.target-panel strong {
  display: block;
  font-size: 54px;
  font-family: Georgia, serif;
  font-weight: 400;
  color: var(--text);
  line-height: 1.1;
  letter-spacing: 0.03em;
}
.metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  text-align: center;
  margin: 19px 0;
}
.metrics > div {
  padding: 14px 7px;
  background: var(--panel-soft);
  border-radius: 7px;
}
.metrics b {
  display: block;
  font-size: 24px;
  line-height: 1.2;
  font-family: Georgia, serif;
  font-weight: 400;
}
.metrics small {
  font-size: 10px;
  color: var(--muted);
}
.metrics.wide {
  margin: 0 0 25px;
}
.sequence-pill {
  padding: 15px;
  color: var(--gold);
  border-radius: 7px;
  background: var(--panel-soft);
  font-family: ui-monospace, SFMono-Regular, monospace;
  letter-spacing: 0.02em;
  line-height: 1.8;
  margin: 14px 0 18px;
}
.bank-list {
  max-height: 260px;
  overflow: auto;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.bank-item {
  display: flex;
  justify-content: space-between;
  text-align: left;
  align-items: center;
  gap: 10px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--text);
  border-radius: 5px;
  padding: 10px 9px;
}
.bank-item:hover,
.bank-item.chosen {
  background: var(--panel-soft);
  border-color: var(--line);
}
.bank-item small {
  color: var(--muted);
  white-space: nowrap;
}
.source-link {
  display: block;
  margin-top: 18px;
  font-size: 12px;
  color: var(--accent);
}
.settings-layout {
  display: grid;
  grid-template-columns: minmax(340px, 1.3fr) minmax(260px, 1fr);
  gap: 24px;
  max-width: 1080px;
}
.feature-status b {
  display: block;
  color: var(--text);
  margin: 16px 0 8px;
}
.fatal {
  max-width: 700px;
  margin: 20vh auto;
  padding: 30px;
  background: var(--panel);
  border: 1px solid var(--danger);
  border-radius: 12px;
}
.practice-status {
  letter-spacing: 0.09em;
}
@media (max-width: 1320px) {
  .navigation {
    width: 225px;
    min-width: 225px;
    padding-left: 14px;
    padding-right: 14px;
  }
  .main-content {
    padding: 40px 30px;
  }
  .workspace-grid {
    gap: 20px;
    grid-template-columns: minmax(280px, 1.1fr) minmax(288px, 0.9fr);
  }
  .panel {
    padding: 23px;
  }
  .piece {
    font-size: clamp(25px, 4vw, 54px);
  }
}
@media (max-width: 980px) {
  .app-shell {
    display: block;
  }
  .navigation {
    position: relative;
    width: 100%;
    height: auto;
    min-width: 0;
    padding: 15px 16px 10px;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }
  .brand {
    padding: 0 0 11px;
  }
  .brand-symbol {
    height: 33px;
    width: 33px;
    font-size: 22px;
  }
  .brand-title {
    font-size: 13px;
  }
  .brand-subtitle {
    font-size: 8px;
  }
  .nav-caption,
  .nav-bottom {
    display: none;
  }
  .navigation nav {
    display: flex;
    flex-direction: row;
    gap: 5px;
    overflow-x: auto;
    padding-bottom: 5px;
  }
  .nav-link {
    width: auto;
    padding: 7px 10px;
    font-size: 11px;
    border-radius: 5px;
  }
  .nav-glyph {
    font-size: 15px;
    width: 14px;
  }
  .main-content {
    padding: 26px 20px 52px;
  }
  .workspace-grid {
    grid-template-columns: minmax(280px, 1.1fr) minmax(275px, 0.9fr);
  }
  .workspace-heading {
    margin-bottom: 26px;
  }
  .workspace-heading h1 {
    font-size: 36px;
  }
  .panel {
    padding: 20px;
  }
}
@media (max-width: 700px) {
  .main-content {
    padding: 22px 16px 48px;
  }
  .workspace-grid,
  .settings-layout {
    display: flex;
    flex-direction: column;
    gap: 18px;
  }
  .board-column,
  .side-column,
  .panel {
    width: 100%;
  }
  .workspace-heading {
    margin-bottom: 23px;
  }
  .workspace-heading h1 {
    font-size: 36px;
  }
  .workspace-heading p {
    font-size: 12px;
  }
  .current-mode {
    display: none;
  }
  .board-mount {
    border-width: 6px;
  }
  .piece {
    font-size: clamp(25px, 8.2vw, 50px);
  }
  .panel {
    padding: 22px;
  }
  .mental-surface {
    min-height: 335px;
  }
  .mental-surface h2 {
    font-size: 56px;
  }
  .board-footer {
    margin-top: 12px;
  }
  .nav-link {
    font-size: 11px;
  }
  .nav-glyph {
    display: none;
  }
  .brand {
    padding-bottom: 8px;
  }
}
@media (max-width: 370px) {
  .main-content {
    padding: 18px 11px;
  }
  .nav-link {
    font-size: 10px;
    padding: 7px;
  }
  .panel {
    padding: 17px;
  }
  .button-row .btn {
    white-space: normal;
  }
  .field-row {
    gap: 8px;
  }
  .piece {
    font-size: clamp(22px, 8vw, 38px);
  }
}
@media (prefers-reduced-motion: reduce) {
  * {
    animation: none !important;
    transition: none !important;
    scroll-behavior: auto !important;
  }
}
.setup-details {
  padding: 10px 0;
  border-top: 1px solid var(--line);
  margin-top: 15px;
}
.setup-details summary {
  cursor: pointer;
  font-weight: 650;
  font-size: 12px;
  color: var(--accent);
  margin-bottom: 10px;
}
.setup-details textarea {
  display: block;
  width: 100%;
  min-height: 72px;
  background: var(--panel-soft);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 10px;
  font-family: ui-monospace, SFMono-Regular, monospace;
  font-size: 11px;
  margin: 11px 0;
  resize: vertical;
}
.review-card h3 { margin-bottom: 8px; }
.eval-chart { display: block; width: 100%; height: 76px; background: var(--panel-soft); border-radius: 8px; margin: 12px 0 20px; }
.eval-zero { stroke: var(--line); stroke-width: 1; stroke-dasharray: 4 4; }
.eval-line { fill: none; stroke: var(--gold); stroke-width: 2.5; stroke-linecap: round; stroke-linejoin: round; }
.critical-row { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 10px 0; border-top: 1px solid var(--line); font-size: 12px; }
.critical-row .btn { flex: 0 0 auto; min-height: 40px; }
.status-message { padding: 10px 12px; border: 1px solid var(--line); border-radius: 8px; background: var(--panel-soft); }
@media (max-width: 430px) { .critical-row { align-items: flex-start; flex-direction: column; } .critical-row .btn { width: 100%; } }

/* Modern platform refresh: quiet surfaces, clear play states, compact working UI. */
:root {
  color-scheme: dark;
  --bg: #0c0d2b;
  --sidebar: #08091f;
  --panel: #12143a;
  --panel-soft: #191c48;
  --line: #26295e;
  --text: #e8eaff;
  --muted: #9ca0dd;
  --accent: #45e5dd;
  --accent-deep: #26295e;
  --secondary: #d0bce9;
  --gold: #ffd141;
  --danger: #fb4fa3;
  --board-light: #e8eaff;
  --board-dark: #6d70b5;
  --on-accent: #0c0d2b;
}
body[data-theme="paper"] {
  color-scheme: light;
  --bg: #f1f0ed;
  --sidebar: #e8eaff;
  --panel: #fcfbff;
  --panel-soft: #edeafd;
  --line: #c9c6e8;
  --text: #101115;
  --muted: #56598f;
  --accent: #6d70b5;
  --accent-deep: #d0bce9;
  --secondary: #6d70b5;
  --gold: #8a6500;
  --danger: #b62b6d;
  --on-accent: #fcfbff;
}
body[data-theme="forest"] {
  color-scheme: dark;
  --bg: #101b18;
  --sidebar: #0b1512;
  --panel: #16251f;
  --panel-soft: #1d342c;
  --line: #30493e;
  --text: #eef5ec;
  --muted: #a0b4a7;
  --accent: #b8d8a8;
  --accent-deep: #294638;
  --secondary: #d8c9a3;
  --gold: #e7c781;
  --danger: #ef9c8f;
  --board-light: #e6e2d2;
  --board-dark: #6f8c76;
  --on-accent: #102016;
}
body[data-theme="ember"] {
  color-scheme: light;
  --bg: #f6ead9;
  --sidebar: #efe0cc;
  --panel: #fffaf1;
  --panel-soft: #f3e3d0;
  --line: #dcc6ab;
  --text: #34251f;
  --muted: #80665a;
  --accent: #a6573c;
  --accent-deep: #edcfb9;
  --secondary: #82689c;
  --gold: #8a6500;
  --danger: #b23a50;
  --board-light: #f4e7d2;
  --board-dark: #b7785c;
  --on-accent: #fffaf1;
}
body { background: var(--bg); font-size: 14px; }
.navigation { width: 232px; min-width: 232px; padding: 26px 16px 22px; background: var(--sidebar); }
.brand { padding: 0 7px 38px; gap: 11px; }
.brand-symbol { width: 40px; height: 40px; border: 0; border-radius: 11px; background: var(--accent-deep); color: var(--accent); font-size: 24px; }
.brand-title { font-size: 15px; font-weight: 750; letter-spacing: .16em; }
.brand-subtitle { font-size: 8px; letter-spacing: .18em; }
.nav-caption { margin: 0 10px 12px; font-size: 9px; }
.navigation nav { gap: 5px; }
.nav-link { min-height: 44px; padding: 10px 12px; border-radius: 8px; font-size: 13px; font-weight: 550; }
.nav-link.active { background: var(--accent-deep); border-color: transparent; color: var(--text); box-shadow: inset 3px 0 0 var(--accent); }
.nav-glyph { color: var(--accent); font-size: 19px; }
.nav-bottom { padding: 20px 10px 6px; }
.main-content { max-width: 1560px; padding: 38px clamp(22px, 3.5vw, 62px) 64px; }
.workspace-heading { margin-bottom: 26px; }
.workspace-heading .overline { margin-bottom: 8px; color: var(--accent); }
.workspace-heading h1 { font-family: inherit; font-size: clamp(30px, 3vw, 42px); line-height: 1.15; font-weight: 700; letter-spacing: -.035em; margin-bottom: 8px; }
.workspace-heading p { font-size: 13px; }
.current-mode { margin-top: 10px; }
.workspace-grid { grid-template-columns: minmax(320px, 1.3fr) minmax(330px, .9fr); gap: 26px; }
.board-topline { min-height: 30px; padding: 0 2px 10px; align-items: center; font-size: 10px; letter-spacing: .11em; }
.board-mount { border: 0; border-radius: 8px; box-shadow: 0 18px 48px #0004, 0 2px 8px #0003; }
.square { transition: filter 100ms ease; }
.square:hover { filter: brightness(1.04); z-index: 1; }
.square.light { color: #26295e; }
.square.dark-square { color: #e8eaff; }
.square.recent { background-image: linear-gradient(#ffd14166, #ffd14166); }
.square.selected { background-image: linear-gradient(#fb4fa366, #fb4fa366); box-shadow: inset 0 0 0 3px #fb4fa3; }
.square.legal-target::after { width: 24%; background: #0c0d2b66; box-shadow: 0 1px 2px #0002; }
.square.capture-target::after { width: 82%; background: transparent; border: clamp(4px, .55vw, 7px) solid #fb4fa3aa; box-shadow: none; }
.square.target { box-shadow: inset 0 0 0 3px var(--secondary); }
.square.path-square { background-image: linear-gradient(#45e5dd55, #45e5dd55); }
.piece-image { display: block; width: 92%; height: 92%; object-fit: contain; pointer-events: none; user-select: none; filter: drop-shadow(0 2px 1px #0003); }
.piece-image.ghost { opacity: .25; }
.piece.disc { font-family: inherit; font-size: clamp(24px, 4vw, 50px); color: var(--secondary); }
.rank-label, .file-label { font-size: clamp(8px, .8vw, 11px); font-weight: 800; opacity: .78; }
.rank-label { top: 4px; left: 4px; }
.file-label { right: 4px; bottom: 3px; }
.board-note { margin-top: 11px; color: var(--text); font-weight: 550; }
.board-footer { border: 0; padding: 0; margin-top: 14px; font-size: 11px; }
.panel { padding: 24px 26px; border-radius: 14px; border-color: var(--line); box-shadow: 0 12px 32px #00000012; }
.panel .overline { color: var(--accent); }
.panel h2 { font-family: inherit; font-size: 22px; font-weight: 700; letter-spacing: -.025em; margin-bottom: 20px; }
.panel h3 { font-size: 12px; letter-spacing: .015em; }
.field-row { margin: 13px 0; }
input:not([type="checkbox"]), select { min-height: 42px; border-radius: 8px; border-color: var(--line); transition: border-color 120ms, background 120ms; }
input:not([type="checkbox"]):hover, select:hover { border-color: var(--muted); }
.check-line { margin: 17px 0; }
.check-line input { width: 17px; height: 17px; accent-color: var(--accent); }
.status-dot { background: var(--accent); box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 12%, transparent); }
.btn { min-height: 42px; border-radius: 8px; padding: 10px 15px; transition: background 120ms, border-color 120ms, filter 120ms; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.btn.primary:hover { filter: brightness(1.06); }
.btn.current { background: var(--accent-deep); border-color: transparent; }
.btn.danger { border-color: var(--danger); }
.button-row { gap: 8px; margin: 15px 0; }
.section-rule { margin: 21px 0; }
.coach-box, .opening-note { padding: 14px 16px !important; border-left: 3px solid var(--accent); border-radius: 9px; }
.move-history { padding: 7px; border-radius: 8px; background: var(--panel-soft); }
.move-chip { min-height: 32px; min-width: 38px; padding: 5px 8px; border-radius: 6px; }
.move-chip:hover, .move-chip.selected-chip { background: var(--accent-deep); }
.subtab { min-height: 38px; }
.subtab.active { border-color: var(--accent); }
.mental-surface { border-radius: 12px; background: radial-gradient(circle at center, var(--panel-soft) 0%, var(--sidebar) 74%); }
.mental-surface h2 { color: var(--text); }
.mental-surface p { color: var(--muted); }
.metrics > div { border: 1px solid var(--line); }
.eval-chart { border: 1px solid var(--line); }
.path-overview, .learning-grid { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(300px, .85fr); gap: 26px; margin-bottom: 26px; }
.path-intro p { max-width: 680px; }
.recommendation-list, .skill-list { display: flex; flex-direction: column; }
.recommendation-card { display: grid; grid-template-columns: 30px minmax(0, 1fr) auto; align-items: center; gap: 14px; padding: 17px 0; border-top: 1px solid var(--line); }
.recommendation-card:first-child { border-top: 0; padding-top: 0; }
.recommendation-card h3 { font-size: 14px; margin: 0 0 5px; }
.recommendation-card p { margin: 0; font-size: 12px; }
.recommendation-number { color: var(--secondary); font-family: ui-monospace, SFMono-Regular, monospace; font-size: 12px; }
.skill-row { padding: 12px 0; border-top: 1px solid var(--line); }
.skill-row:first-child { border-top: 0; padding-top: 0; }
.skill-heading { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 7px; }
.skill-heading span { font-weight: 650; }
.skill-heading b { color: var(--accent); font-family: ui-monospace, SFMono-Regular, monospace; }
.skill-row meter { display: block; width: 100%; height: 8px; appearance: none; background: var(--line); border: 0; border-radius: 999px; overflow: hidden; }
.skill-row meter::-webkit-meter-bar { background: var(--line); border: 0; border-radius: 999px; }
.skill-row meter::-webkit-meter-optimum-value { background: var(--accent); border-radius: 999px; }
.skill-row meter::-moz-meter-bar { background: var(--accent); border-radius: 999px; }
.skill-row small { display: block; margin-top: 7px; color: var(--muted); font-size: 11px; }
.activity-panel { margin-top: 0; }
.activity-row { display: flex; align-items: center; justify-content: space-between; gap: 18px; padding: 12px 0; border-top: 1px solid var(--line); }
.activity-row span:first-child { min-width: 0; }
.activity-row small { display: block; color: var(--muted); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.activity-result { flex: 0 0 auto; color: var(--muted); font-size: 12px; }
.activity-result.positive { color: var(--accent); }

.today-layout { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(280px, .8fr); gap: 32px; max-width: 1120px; }
.today-focus { display: flex; flex-direction: column; align-items: flex-start; padding: clamp(28px, 4vw, 48px); border: 1px solid var(--line); border-radius: 14px; background: var(--accent-deep); }
.today-focus .overline { color: var(--accent); }
.today-focus h2 { max-width: 18ch; margin: 14px 0; font-size: clamp(28px, 3.5vw, 44px); line-height: 1.12; letter-spacing: -.035em; }
.today-reason { max-width: 60ch; margin: 0 0 22px; color: var(--text); font-size: 16px; line-height: 1.65; }
.today-focus .helper { max-width: 58ch; margin: 18px 0 0; }
.today-details { padding-top: 8px; }
.today-details h2 { margin: 0 0 20px; font-size: 19px; }
.today-details > p { color: var(--muted); line-height: 1.65; }
.today-metrics { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 22px; }
.today-metrics > div { display: flex; align-items: flex-start; gap: 12px; padding-top: 14px; border-top: 1px solid var(--line); }
.today-metrics b { color: var(--accent); font-size: 30px; line-height: 1; }
.today-metrics span { color: var(--muted); font-size: 12px; line-height: 1.45; }
.today-links { display: flex; flex-wrap: wrap; gap: 8px; }
.install-panel { margin-top: 24px; padding-top: 22px; border-top: 1px solid var(--line); }
.install-heading { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.install-heading h3 { margin: 0; }
.install-state { color: var(--muted); font-size: 12px; }
.install-checks { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin: 16px 0; }
.install-check { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 11px 12px; border-radius: 8px; background: var(--panel-soft); }
.install-check span { color: var(--muted); font-size: 12px; }
.install-check b { text-align: right; font-size: 12px; }
.install-result { padding: 12px 14px; border-left: 3px solid var(--accent); border-radius: 8px; background: var(--panel-soft); color: var(--text); }
@media (max-width: 800px) {
  .today-layout { grid-template-columns: 1fr; gap: 24px; }
  .today-focus { padding: 26px; }
  .today-details { padding-top: 0; }
  .install-checks { grid-template-columns: 1fr; }
}

@media (max-width: 1320px) {
  .navigation { width: 218px; min-width: 218px; }
  .main-content { padding: 34px 28px 58px; }
  .workspace-grid { grid-template-columns: minmax(300px, 1.15fr) minmax(310px, .9fr); gap: 22px; }
  .panel { padding: 22px; }
}
@media (max-width: 980px) {
  .navigation { position: sticky; top: 0; z-index: 20; width: 100%; min-width: 0; padding: 12px 16px 8px; background: color-mix(in srgb, var(--sidebar) 94%, transparent); backdrop-filter: blur(14px); }
  .brand { padding: 0 0 10px; }
  .brand-symbol { width: 34px; height: 34px; border-radius: 9px; font-size: 20px; }
  .navigation nav { gap: 5px; padding-bottom: 3px; scrollbar-width: none; }
  .navigation nav::-webkit-scrollbar { display: none; }
  .nav-link { min-height: 38px; padding: 8px 11px; }
  .nav-link.active { box-shadow: none; }
  .main-content { padding: 26px 20px 50px; }
  .workspace-grid { grid-template-columns: minmax(280px, 1.1fr) minmax(285px, .9fr); }
  .path-overview, .learning-grid { grid-template-columns: 1fr; gap: 22px; }
}
@media (max-width: 700px) {
  .main-content { padding: 22px 14px 44px; }
  .workspace-heading { margin-bottom: 19px; }
  .workspace-heading h1 { font-size: 30px; }
  .workspace-grid, .settings-layout { gap: 18px; }
  .board-mount { border-radius: 6px; }
  .board-footer { font-size: 11px; }
  .panel { padding: 20px; border-radius: 12px; }
  .panel h2 { font-size: 21px; }
  .btn { min-height: 44px; }
  .nav-glyph { display: inline; width: 15px; font-size: 15px; }
  .nav-link { font-size: 11px; }
  .move-chip { min-height: 38px; min-width: 42px; }
  .rank-label, .file-label { font-size: 8px; }
  .recommendation-card { grid-template-columns: 26px minmax(0, 1fr); }
  .recommendation-card .btn { grid-column: 2; justify-self: start; }
  .activity-row { align-items: flex-start; }
}
@media (max-width: 370px) {
  .main-content { padding: 18px 10px 40px; }
  .navigation { padding-left: 10px; padding-right: 10px; }
  .panel { padding: 17px; }
  .workspace-heading h1 { font-size: 27px; }
}

/* Quiet, compositor-friendly polish; never block input or obscure position. */
body, .navigation, .panel, .board-mount {
  transition: background-color 180ms ease, color 180ms ease, border-color 180ms ease, box-shadow 180ms ease;
}
.btn, .nav-link, .subtab, .move-chip {
  transition: background-color 140ms ease, border-color 140ms ease, color 140ms ease, filter 140ms ease, transform 140ms ease;
}
.btn:active, .nav-link:active, .subtab:active, .move-chip:active { transform: scale(.98); }
@media (hover: hover) {
  .btn:hover { transform: translateY(-1px); }
}
.main-content.view-enter > * { animation: view-in 220ms cubic-bezier(.2, .7, .2, 1) both; }
.square.legal-target::after { animation: target-in 140ms ease-out both; }
@keyframes view-in {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes target-in {
  from { opacity: 0; transform: scale(.72); }
  to { opacity: 1; transform: scale(1); }
}

/* Optional teaching layer: visible when useful, absent when dismissed. */
.beginner-guide {
  position: relative;
  margin-bottom: 18px;
  padding: 22px 24px;
  border: 1px solid var(--accent);
  border-radius: 14px;
  background: color-mix(in srgb, var(--panel) 88%, var(--accent));
  box-shadow: 0 12px 32px #00000012;
}
.guide-topline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.guide-topline .overline,
.move-lesson .overline { color: var(--accent); }
.guide-close {
  flex: 0 0 auto;
  width: 44px;
  height: 44px;
  margin: -12px -12px -12px 0;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--muted);
  font-size: 25px;
  line-height: 1;
}
.guide-close:hover { background: var(--panel-soft); color: var(--text); }
.beginner-guide h2 {
  margin: 8px 0 12px;
  font-size: 21px;
  line-height: 1.25;
  letter-spacing: -.02em;
}
.beginner-guide p { color: var(--muted); }
.beginner-steps {
  margin: 14px 0;
  padding-left: 22px;
  color: var(--muted);
}
.beginner-steps li { padding: 4px 0 4px 3px; }
.beginner-steps b { color: var(--text); }
.move-lesson {
  margin: 16px 0;
  padding: 15px 16px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--panel-soft);
}
.move-lesson .move-reading { color: var(--text); font-weight: 600; margin-bottom: 10px; }
.move-lesson .move-purpose { color: var(--text); }
.move-lesson ul { margin: 9px 0 0; padding-left: 19px; color: var(--muted); font-size: 12px; }
.move-lesson li + li { margin-top: 7px; }
.coach-preferred {
  margin-top: 12px;
  padding: 13px 15px;
  border-radius: 9px;
  background: var(--panel-soft);
  color: var(--muted);
  font-size: 12px;
}
@media (max-width: 700px) {
  .beginner-guide { padding: 19px; }
  .beginner-guide .button-row .btn { flex: 1 1 auto; }
  .guide-language { max-width: none; align-items: stretch; flex-direction: column; }
  .guide-language select { width: 100%; max-width: none; }
  .move-lesson { padding: 14px; }
}

/* Lightweight language and reading preferences; all remain local. */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 1000;
  padding: 10px 15px;
  border-radius: 8px;
  background: var(--panel);
  color: var(--text);
  transform: translateY(-180%);
}
.skip-link:focus { transform: translateY(0); }
.guide-language { max-width: 290px; margin: 8px 0 16px; }
body[data-motion="reduce"] *,
body[data-motion="reduce"] *::before,
body[data-motion="reduce"] *::after {
  animation: none !important;
  transition: none !important;
  scroll-behavior: auto !important;
}
body[data-text-size="large"] .main-content { font-size: 17px; }
body[data-text-size="large"] .workspace-heading p,
body[data-text-size="large"] .panel p,
body[data-text-size="large"] .panel li,
body[data-text-size="large"] .helper,
body[data-text-size="large"] .coach-preferred,
body[data-text-size="large"] .move-lesson ul { font-size: inherit; }
body[data-text-size="large"] .nav-link { font-size: 15px; }
body[data-text-size="large"] .nav-bottom small { font-size: 14px; }