:root {
  --bg: #14110d;
  --panel: #211c15;
  --panel-2: #2b251c;
  --line: #3a3226;
  --text: #ede4d3;
  --muted: #9a8e78;
  --brass: #d9a441;
  --brass-bright: #ffcf6b;
  --green: #6fcf6f;
  --cyan: #57c7d4;
  --red: #e0623e;
  --shadow: rgba(0, 0, 0, 0.45);
}

* {
  box-sizing: border-box;
}
html,
body {
  margin: 0;
  height: 100%;
}
body {
  background: radial-gradient(1200px 800px at 70% -10%, #1d1812, var(--bg));
  color: var(--text);
  font: 15px/1.5 ui-sans-serif, system-ui, "Segoe UI", Roboto, sans-serif;
  display: flex;
  flex-direction: column;
}

/* ---- top bar ---- */
.topbar {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 12px 18px;
  background: linear-gradient(180deg, #241e16, #1a160f);
  border-bottom: 1px solid var(--line);
}
.brand {
  font-weight: 700;
  letter-spacing: 0.3px;
  color: var(--brass-bright);
  white-space: nowrap;
}
.tabs {
  display: flex;
  gap: 6px;
  flex: 1;
}
.tabs button {
  background: transparent;
  color: var(--muted);
  border: 1px solid transparent;
  padding: 6px 14px;
  border-radius: 8px;
  cursor: pointer;
  font: inherit;
}
.tabs button:hover {
  color: var(--text);
  background: #ffffff0a;
}
.tabs button.active {
  color: #1a160f;
  background: var(--brass);
  font-weight: 600;
}
.lang {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 13px;
}
.lang select {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 7px;
  padding: 5px 8px;
  font: inherit;
}

/* ---- layout ---- */
main {
  flex: 1;
  padding: 20px;
  display: flex;
  justify-content: center;
  overflow: auto;
}
.wrap {
  width: min(1000px, 100%);
}
.cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
@media (max-width: 720px) {
  .cols {
    grid-template-columns: 1fr;
  }
}
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 16px;
  box-shadow: 0 6px 18px var(--shadow);
}
.card h2 {
  margin: 0 0 12px;
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--muted);
}

.footer {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 18px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}
.footer a {
  color: var(--brass);
  text-decoration: none;
}

/* ---- language picker ---- */
.langpick {
  display: grid;
  gap: 10px;
  max-width: 360px;
  margin: 8vh auto 0;
  text-align: center;
}
.langpick h1 {
  font-size: 18px;
  color: var(--brass-bright);
}
.langpick .grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
.langpick button {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 12px;
  cursor: pointer;
  font: inherit;
}
.langpick button:hover {
  border-color: var(--brass);
  color: var(--brass-bright);
}

/* ---- browse ---- */
.filter,
input.field,
.solve-form input,
.solve-form select {
  width: 100%;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 9px 11px;
  font: inherit;
}

/* format help / examples */
.help {
  margin: 2px 0 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #00000022;
}
.help summary {
  cursor: pointer;
  padding: 9px 11px;
  color: var(--brass);
  user-select: none;
}
.help[open] summary {
  border-bottom: 1px solid var(--line);
}
.help-body {
  padding: 6px 12px 12px;
  font-size: 13.5px;
  color: var(--text);
}
.help-body p {
  margin: 8px 0;
}
.help-body code {
  background: #ffffff14;
  padding: 1px 5px;
  border-radius: 4px;
  font-family: ui-monospace, Menlo, Consolas, monospace;
}
.help-body pre {
  background: #0e0b07;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 12px;
  overflow: auto;
  font-size: 12.5px;
  color: var(--brass-bright);
  margin: 8px 0;
}
.locklist {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
  max-height: 60vh;
  overflow: auto;
}
.locklist li {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 11px;
  border-radius: 8px;
  cursor: pointer;
}
.locklist li:hover {
  background: #ffffff0a;
}
.locklist li.sel {
  background: #ffcf6b1a;
  outline: 1px solid var(--brass);
}
.locklist .check {
  color: var(--green);
}
.locklist .del {
  margin-left: auto;
  color: var(--muted);
  border: none;
  background: none;
  cursor: pointer;
  font-size: 15px;
}
.locklist .del:hover {
  color: var(--red);
}
.kv {
  display: grid;
  gap: 3px;
}
.mono {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
}
.muted {
  color: var(--muted);
}

/* ---- solve form ---- */
.solve-form {
  display: grid;
  gap: 10px;
}
.solve-form .row {
  display: grid;
  grid-template-columns: 90px 1fr;
  align-items: center;
  gap: 10px;
}
.solve-form label {
  color: var(--muted);
  font-size: 13px;
}
.btn {
  background: var(--brass);
  color: #1a160f;
  border: none;
  border-radius: 9px;
  padding: 10px 16px;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}
.btn:hover {
  background: var(--brass-bright);
}
.btn.ghost {
  background: transparent;
  color: var(--brass);
  border: 1px solid var(--line);
}
.btn.ghost:hover {
  border-color: var(--brass);
  color: var(--brass-bright);
}
.btn-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.error {
  color: var(--red);
}
.ok {
  color: var(--green);
  font-weight: 600;
}

/* ---- step / lock visualization ---- */
.step-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 16px;
}
@media (max-width: 820px) {
  .step-grid {
    grid-template-columns: 1fr;
  }
}
.lockwrap {
  position: relative;
}
.controls {
  display: flex;
  gap: 8px;
  align-items: center;
  margin-top: 12px;
  flex-wrap: wrap;
}
.controls .spacer {
  flex: 1;
}
.progress {
  color: var(--muted);
  font-size: 13px;
  margin-top: 8px;
}

/* current move keycap */
.move {
  text-align: center;
  margin-bottom: 12px;
}
.move .who {
  color: var(--brass-bright);
  font-weight: 600;
}
.keycap {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  margin: 8px auto;
  border-radius: 12px;
  background: linear-gradient(180deg, #3a3220, #241e14);
  border: 1px solid var(--line);
  border-bottom-width: 4px;
  font-size: 30px;
  font-weight: 700;
  color: var(--brass-bright);
  box-shadow: 0 4px 0 #00000055;
}
.arrows {
  font-size: 22px;
  letter-spacing: 6px;
  color: var(--text);
}

/* steps checklist */
.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  max-height: 48vh;
  overflow: auto;
  font-family: ui-monospace, Menlo, Consolas, monospace;
}
.steps li {
  padding: 5px 10px;
  border-radius: 6px;
  display: flex;
  gap: 10px;
}
.steps li.done {
  color: var(--muted);
}
.steps li.cur {
  background: var(--brass);
  color: #1a160f;
  font-weight: 700;
}
.steps li .mark {
  width: 14px;
}

/* SVG lock pins glow when seated */
.pin.seated {
  filter: drop-shadow(0 0 6px var(--green));
}
.plate-row {
  transition: transform 0.18s cubic-bezier(0.3, 0.7, 0.3, 1);
}
.plate-row.fast {
  transition: transform 0.06s linear;
}