:root {
  color-scheme: dark;
  --ink: #eef5f7;
  --muted: #aab8c4;
  --panel: rgba(19, 31, 41, .97);
  --panel-2: rgba(28, 47, 60, .94);
  --line: rgba(235, 246, 250, .14);
  --mint: #70edc5;
  --blue: #80b9ff;
  --gold: #ffd36e;
  --shadow: 0 24px 70px rgba(0, 0, 0, .35);
  --white: #edf6f8;
  --yellow: #ffd55a;
  --green: #4ae18b;
  --blue-sticker: #579cf3;
  --orange: #ff9a55;
  --red: #f46275;
}

* { box-sizing: border-box; }
html, body { min-height: 100%; }
body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at 18% 8%, rgba(112, 237, 197, .13), transparent 30rem),
    radial-gradient(circle at 88% 92%, rgba(128, 185, 255, .14), transparent 34rem),
    #091118;
}
button { font: inherit; }
button { cursor: pointer; }
button:focus-visible, a:focus-visible { outline: 3px solid var(--gold); outline-offset: 3px; }

.cube-shell { display: grid; min-height: 100vh; padding: 28px 18px; place-items: center; }
.cube-card {
  width: min(1040px, 100%);
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 30px;
  background: linear-gradient(145deg, rgba(26, 45, 56, .98), rgba(12, 24, 31, .99));
  box-shadow: var(--shadow);
}
.cube-header { display: flex; align-items: flex-start; justify-content: space-between; gap: 20px; padding: 28px 30px 20px; }
.cube-nav-link { display: inline-block; margin-bottom: 12px; color: var(--muted); font-size: .86rem; font-weight: 750; text-decoration: none; }
.cube-nav-link:hover { color: var(--mint); }
.cube-eyebrow { margin: 0 0 5px; color: var(--mint); font-size: .72rem; font-weight: 900; letter-spacing: .16em; }
h1, h2, p { margin-top: 0; }
h1 { margin-bottom: 0; font-size: clamp(2.15rem, 5vw, 3.65rem); line-height: .95; letter-spacing: -.065em; }
h1 span { color: var(--mint); }
h2 { margin-bottom: 10px; font-size: 1.44rem; letter-spacing: -.04em; }
.header-action, .primary-action, .secondary-action, .text-action, .turn-row button {
  border: 0;
  color: var(--ink);
  transition: transform .15s ease, background .15s ease, border-color .15s ease, opacity .15s ease;
}
.header-action { min-height: 44px; padding: 0 15px; border-radius: 14px; background: rgba(112, 237, 197, .12); color: var(--mint); border: 1px solid rgba(112, 237, 197, .2); font-weight: 850; }
.header-action:hover, .primary-action:hover { transform: translateY(-1px); }

.cube-hud { display: grid; grid-template-columns: 132px 132px 1fr; gap: 1px; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); background: var(--line); }
.hud-item, .hud-status { min-height: 75px; padding: 16px 20px; background: rgba(9, 19, 26, .48); }
.hud-item span { display: block; margin-bottom: 5px; color: var(--muted); font-size: .72rem; font-weight: 850; letter-spacing: .09em; text-transform: uppercase; }
.hud-item strong { font-size: 1.15rem; }
.hud-status { display: flex; align-items: center; color: #d3e0e6; font-size: .96rem; line-height: 1.45; }

.cube-layout { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(330px, .9fr); gap: 24px; padding: 30px; }
.cube-board-wrap { display: grid; align-content: center; justify-items: center; padding: 8px 0 0; }
.cube-net { --face: clamp(79px, 13vw, 137px); display: grid; grid-template-columns: repeat(4, var(--face)); grid-template-rows: repeat(3, var(--face)); gap: 7px; filter: drop-shadow(0 18px 25px rgba(0, 0, 0, .24)); }
.cube-face { display: grid; grid-template-columns: repeat(3, 1fr); gap: 4px; padding: 5px; border: 1px solid rgba(243, 249, 252, .15); border-radius: 12px; background: #0d1820; }
.face-u { grid-column: 2; grid-row: 1; }
.face-l { grid-column: 1; grid-row: 2; }
.face-f { grid-column: 2; grid-row: 2; }
.face-r { grid-column: 3; grid-row: 2; }
.face-b { grid-column: 4; grid-row: 2; }
.face-d { grid-column: 2; grid-row: 3; }
.sticker { min-width: 0; min-height: 0; border-radius: 4px; border: 1px solid rgba(15, 20, 25, .18); box-shadow: inset 0 1px 0 rgba(255, 255, 255, .32), inset 0 -2px 0 rgba(0, 0, 0, .1); }
.sticker[data-color="W"] { background: var(--white); }
.sticker[data-color="Y"] { background: var(--yellow); }
.sticker[data-color="G"] { background: var(--green); }
.sticker[data-color="B"] { background: var(--blue-sticker); }
.sticker[data-color="O"] { background: var(--orange); }
.sticker[data-color="R"] { background: var(--red); }
.board-caption { max-width: 505px; margin: 22px 0 0; color: var(--muted); text-align: center; font-size: .84rem; line-height: 1.5; }

.cube-controls { display: flex; min-width: 0; flex-direction: column; padding: 26px; border: 1px solid var(--line); border-radius: 24px; background: rgba(8, 18, 25, .46); }
.control-heading > p:not(.cube-eyebrow) { margin-bottom: 0; color: var(--muted); font-size: .92rem; line-height: 1.55; }
.turn-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 9px; margin: 22px 0 20px; }
.turn-row { display: grid; grid-template-columns: 34px 1fr 1fr; min-height: 49px; overflow: hidden; border: 1px solid var(--line); border-radius: 14px; background: rgba(255, 255, 255, .035); }
.turn-row strong { display: grid; place-items: center; color: var(--mint); font-size: 1rem; }
.turn-row button { border-left: 1px solid var(--line); background: transparent; color: #e9f1f4; font-size: 1.15rem; }
.turn-row button:hover { background: rgba(112, 237, 197, .12); color: var(--mint); }
.utility-actions { display: grid; gap: 10px; margin-top: auto; }
.primary-action, .secondary-action { min-height: 51px; padding: 0 17px; border-radius: 15px; font-weight: 900; }
.primary-action { background: var(--mint); color: #082019; box-shadow: 0 10px 24px rgba(112, 237, 197, .17); }
.secondary-action { border: 1px solid var(--line); background: rgba(255, 255, 255, .06); }
.secondary-action:hover { border-color: rgba(112, 237, 197, .34); background: rgba(112, 237, 197, .10); }
.secondary-action:disabled { cursor: not-allowed; opacity: .45; }
.text-action { padding: 5px; background: transparent; color: var(--muted); font-size: .84rem; text-decoration: underline; text-underline-offset: 3px; }
.text-action:hover { color: #fff; }
.keyboard-hint { margin-top: 16px; color: var(--muted); font-size: .78rem; line-height: 1.5; }
.keyboard-hint strong { color: #c9d8df; }

.scramble-card { display: grid; grid-template-columns: 160px 1fr; gap: 16px; align-items: center; margin: 0 30px; padding: 15px 18px; border: 1px solid var(--line); border-radius: 16px; background: rgba(5, 14, 20, .34); }
.scramble-card > span { color: var(--muted); font-size: .77rem; font-weight: 850; letter-spacing: .08em; text-transform: uppercase; }
.scramble-card code { overflow-wrap: anywhere; color: var(--gold); font: 800 .92rem/1.5 ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace; }
.cube-footer { display: flex; gap: 9px; justify-content: center; padding: 20px 30px 25px; color: var(--muted); font-size: .8rem; text-align: center; }

@media (max-width: 850px) {
  .cube-layout { grid-template-columns: 1fr; }
  .cube-controls { max-width: 630px; width: 100%; justify-self: center; }
  .cube-net { --face: clamp(72px, 19vw, 128px); }
}
@media (max-width: 610px) {
  .cube-shell { padding: 12px; }
  .cube-card { border-radius: 24px; }
  .cube-header { padding: 22px 20px 18px; }
  .header-action { min-height: 40px; padding: 0 11px; font-size: .81rem; }
  .cube-hud { grid-template-columns: 1fr 1fr; }
  .hud-status { grid-column: 1 / -1; min-height: 60px; }
  .cube-layout { gap: 18px; padding: 22px 18px; }
  .cube-net { --face: calc((100vw - 70px) / 4); gap: 4px; }
  .cube-face { gap: 2px; padding: 3px; border-radius: 8px; }
  .sticker { border-radius: 2px; }
  .cube-controls { padding: 20px; }
  .turn-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .scramble-card { grid-template-columns: 1fr; gap: 5px; margin: 0 18px; }
  .cube-footer { padding: 18px 18px 22px; flex-wrap: wrap; }
}
@media (max-width: 370px) {
  .cube-header { flex-direction: column; }
  .cube-net { --face: calc((100vw - 52px) / 4); }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; } }