:root {
  --c64-blue: #2e2c9b;
  --c64-light-blue: #706deb;
  --c64-ink: #d9dbff;
  --c64-panel: rgba(7, 18, 24, 0.94);
  --c64-panel-soft: rgba(15, 36, 43, 0.9);
  --c64-border: rgba(98, 231, 224, 0.34);
  --c64-accent: #62e7e0;
  --c64-warm: #e8a36c;
}

body {
  background:
    radial-gradient(circle at 50% -20%, rgba(38, 108, 120, 0.22), transparent 48rem),
    #061014;
}

.c64-lab-page {
  width: 100%;
  max-width: clamp(1280px, 92vw, 1760px);
  margin-inline: auto;
  padding-bottom: 3rem;
}

.c64-lab-page main {
  max-width: clamp(1100px, 80vw, 1600px);
}

.c64-hero {
  margin-bottom: 1rem;
}

.c64-hero h1 .name {
  display: inline;
}

.c64-hero-copy {
  max-width: 880px;
}

.c64-accuracy-badge {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin: 0.65rem 0 1rem;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--c64-border);
  border-radius: 999px;
  color: var(--c64-accent);
  background: rgba(9, 26, 31, 0.8);
  font: 700 0.75rem/1.35 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  letter-spacing: 0.04em;
}

.c64-primary-action {
  min-height: 48px;
}

.c64-lab {
  max-width: 1440px;
  margin-inline: auto;
  scroll-margin-top: 1rem;
}

.c64-workspace {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 370px);
  gap: 1rem;
  align-items: start;
}

.c64-machine-panel,
.c64-lesson-panel,
.c64-reference-card,
.c64-memory-panel,
.c64-transcript-panel,
.c64-program-panel {
  border: 1px solid var(--c64-border);
  border-radius: 12px;
  background: var(--c64-panel);
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.25);
}

.c64-machine-panel {
  min-width: 0;
  padding: 0.85rem;
}

.c64-machine-heading,
.c64-lesson-heading,
.c64-panel-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.c64-machine-heading h2,
.c64-lesson-heading h2,
.c64-panel-heading h3 {
  margin: 0;
  color: #e4fbff;
  font: 700 clamp(0.95rem, 2vw, 1.1rem)/1.3 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.c64-runtime-status,
.c64-sound-status {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0.25rem 0.55rem;
  border: 1px solid rgba(98, 231, 224, 0.32);
  border-radius: 999px;
  color: var(--c64-accent);
  font: 700 0.7rem/1.2 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.c64-runtime-status[data-state="running"]::before,
.c64-sound-status[data-activity="true"]::before {
  content: "";
  width: 0.45rem;
  height: 0.45rem;
  margin-right: 0.4rem;
  border-radius: 50%;
  background: #78f59a;
  box-shadow: 0 0 10px #78f59a;
}

.c64-runtime-status[data-state="paused"],
.c64-runtime-status[data-state="error"] {
  color: #ffd39e;
  border-color: rgba(232, 163, 108, 0.55);
}

.c64-display-frame {
  position: relative;
  width: 100%;
  max-width: 920px;
  margin-inline: auto;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border: 10px solid #7779d9;
  border-radius: 14px;
  background: var(--c64-light-blue);
  box-shadow:
    0 0 0 2px rgba(219, 221, 255, 0.16) inset,
    0 20px 55px rgba(46, 44, 155, 0.28);
}

.c64-display-frame canvas {
  display: block;
  width: 100%;
  height: 100%;
  image-rendering: pixelated;
}

.c64-crt-enabled .c64-display-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(
    to bottom,
    rgba(0, 0, 0, 0) 0,
    rgba(0, 0, 0, 0) 3px,
    rgba(0, 0, 0, 0.12) 4px
  );
  mix-blend-mode: multiply;
}

.c64-crt-enabled .c64-display-frame {
  box-shadow:
    0 0 0 2px rgba(219, 221, 255, 0.16) inset,
    0 0 38px rgba(112, 109, 235, 0.38),
    0 20px 55px rgba(0, 0, 0, 0.36);
}

.c64-canvas-description {
  margin: 0.65rem 0 0;
  color: #bcd3d6;
  font-size: 0.82rem;
}

.c64-command-form {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 0.6rem;
  margin-top: 0.8rem;
}

.c64-command-field {
  min-width: 0;
}

.c64-command-field label {
  display: block;
  margin-bottom: 0.3rem;
  color: var(--c64-accent);
  font: 700 0.72rem/1.2 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.c64-command-field input {
  box-sizing: border-box;
  width: 100%;
  min-height: 48px;
  padding: 0.7rem 0.8rem;
  border: 1px solid rgba(167, 171, 255, 0.65);
  border-radius: 7px;
  color: #f2f2ff;
  background: #24248b;
  font: 700 1rem/1.35 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  text-transform: uppercase;
  caret-color: #fff;
}

.c64-command-field input:disabled {
  opacity: 0.72;
  cursor: not-allowed;
}

.c64-command-form > button,
.c64-control-grid button,
.c64-special-keys button,
.c64-lesson-actions button,
.c64-lesson-tab {
  min-height: 44px;
  border: 1px solid rgba(98, 231, 224, 0.38);
  border-radius: 7px;
  color: #dffcff;
  background: rgba(18, 54, 62, 0.95);
  font: 700 0.78rem/1.25 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  cursor: pointer;
}

.c64-command-form > button {
  align-self: end;
  min-width: 92px;
}

.c64-command-form button:hover,
.c64-control-grid button:hover,
.c64-special-keys button:hover,
.c64-lesson-actions button:hover,
.c64-lesson-tab:hover {
  border-color: var(--c64-accent);
  background: rgba(25, 73, 82, 0.98);
}

.c64-command-form button:disabled,
.c64-control-grid button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.c64-control-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 0.45rem;
  margin-top: 0.65rem;
}

.c64-control-grid button[aria-pressed="true"] {
  color: #081619;
  border-color: var(--c64-accent);
  background: var(--c64-accent);
}

.c64-control-grid .c64-stop {
  border-color: rgba(232, 163, 108, 0.62);
  color: #ffd6ae;
}

.c64-special-keys {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 0.55rem;
}

.c64-special-keys button {
  flex: 1 1 72px;
  padding-inline: 0.45rem;
}

.c64-machine-secondary {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 0.75rem;
  margin-top: 0.75rem;
}

.c64-transcript-panel,
.c64-program-panel {
  min-width: 0;
  padding: 0.7rem;
  background: rgba(5, 14, 18, 0.78);
}

.c64-transcript-panel h3,
.c64-program-panel h3,
.c64-memory-panel h3 {
  margin: 0 0 0.5rem;
  color: var(--c64-accent);
  font: 700 0.78rem/1.3 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  text-transform: uppercase;
}

.c64-transcript,
.c64-program-listing,
.c64-screen-text {
  box-sizing: border-box;
  width: 100%;
  margin: 0;
  color: #d8e8ea;
  background: #071014;
  font: 0.78rem/1.45 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.c64-transcript,
.c64-program-listing {
  max-height: 230px;
  padding: 0.6rem;
  overflow: auto;
  border: 1px solid rgba(98, 231, 224, 0.18);
  border-radius: 6px;
}

.c64-screen-text {
  max-height: 22rem;
  padding: 0.75rem;
  overflow: auto;
}

.c64-lesson-panel {
  position: sticky;
  top: 0.75rem;
  padding: 0.85rem;
}

.c64-lesson-heading {
  align-items: flex-start;
}

.c64-lesson-step {
  margin: 0 0 0.25rem;
  color: var(--c64-warm);
  font: 700 0.72rem/1.2 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  letter-spacing: 0.08em;
}

.c64-lesson-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.35rem;
  max-height: 245px;
  margin-bottom: 0.8rem;
  overflow: auto;
}

.c64-lesson-tab {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.4rem;
  align-items: center;
  min-height: 48px;
  padding: 0.4rem 0.5rem;
  text-align: left;
}

.c64-lesson-tab span {
  color: var(--c64-warm);
}

.c64-lesson-tab b {
  overflow: hidden;
  font-size: 0.68rem;
  text-overflow: ellipsis;
}

.c64-lesson-tab[aria-current="true"] {
  color: #071619;
  border-color: var(--c64-accent);
  background: var(--c64-accent);
}

.c64-lesson-tab[aria-current="true"] span {
  color: #154b4a;
}

.c64-lesson-tab.is-complete:not([aria-current="true"]) {
  border-color: rgba(120, 245, 154, 0.58);
}

.c64-lesson-copy {
  display: grid;
  gap: 0.65rem;
}

.c64-lesson-block {
  padding: 0.65rem;
  border-left: 3px solid rgba(98, 231, 224, 0.5);
  background: rgba(15, 36, 43, 0.72);
}

.c64-lesson-block h3 {
  margin: 0 0 0.25rem;
  color: var(--c64-accent);
  font: 700 0.69rem/1.25 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  letter-spacing: 0.06em;
}

.c64-lesson-block p {
  margin: 0;
  color: #d5e4e6;
  font-size: 0.88rem;
  line-height: 1.5;
}

.c64-hint {
  margin: 0;
  padding: 0.65rem;
  border: 1px dashed rgba(232, 163, 108, 0.58);
  border-radius: 7px;
  color: #ffe1be;
  background: rgba(64, 39, 24, 0.45);
  font-size: 0.85rem;
}

.c64-lesson-complete {
  margin: 0;
  padding: 0.7rem;
  border: 1px solid rgba(120, 245, 154, 0.5);
  border-radius: 7px;
  color: #caffd8;
  background: rgba(21, 69, 40, 0.45);
  font: 700 0.78rem/1.45 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.c64-lesson-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.45rem;
  margin-top: 0.75rem;
}

.c64-lesson-actions button {
  padding: 0.5rem;
}

.c64-lesson-actions .c64-next,
.c64-lesson-actions .c64-free {
  border-color: rgba(232, 163, 108, 0.55);
}

.c64-memory-panel {
  margin-top: 1rem;
  padding: 0.85rem;
}

.c64-memory-table {
  width: 100%;
  border-collapse: collapse;
  color: #d8e8ea;
  font: 0.78rem/1.4 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.c64-memory-table th,
.c64-memory-table td {
  padding: 0.45rem 0.55rem;
  border-bottom: 1px solid rgba(98, 231, 224, 0.16);
  text-align: left;
}

.c64-memory-table th {
  color: var(--c64-accent);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.c64-supporting {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.c64-reference-card {
  padding: 1rem;
}

.c64-reference-card h2 {
  margin-top: 0;
  color: #e4fbff;
  font-size: 1.1rem;
}

.c64-reference-card h3 {
  color: var(--c64-accent);
  font-size: 0.95rem;
}

.c64-reference-card p,
.c64-reference-card li,
.c64-reference-card dd {
  color: #c9dbdd;
  line-height: 1.65;
}

.c64-reference-card code {
  color: #fff;
  background: rgba(112, 109, 235, 0.24);
  padding: 0.1rem 0.25rem;
  border-radius: 3px;
}

.c64-address-list {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.35rem 0.8rem;
}

.c64-address-list dt {
  color: var(--c64-warm);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-weight: 700;
}

.c64-address-list dd {
  margin: 0;
}

.c64-related-links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.55rem;
}

.c64-related-links a {
  display: block;
  padding: 0.7rem;
  border: 1px solid var(--c64-border);
  border-radius: 7px;
  color: var(--c64-accent);
  text-decoration: none;
}

.c64-related-links a:hover {
  border-color: var(--c64-accent);
}

.c64-visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.c64-command-field input:focus-visible,
.c64-command-form button:focus-visible,
.c64-control-grid button:focus-visible,
.c64-special-keys button:focus-visible,
.c64-lesson-actions button:focus-visible,
.c64-lesson-tab:focus-visible,
.c64-related-links a:focus-visible {
  outline: 3px solid var(--c64-warm);
  outline-offset: 3px;
}

@media (min-width: 1600px) {
  .c64-workspace {
    grid-template-columns: minmax(0, 1fr) minmax(370px, 420px);
    gap: clamp(1rem, 1.25vw, 1.5rem);
  }

  .c64-supporting {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 980px) {
  .c64-workspace {
    grid-template-columns: 1fr;
  }

  .c64-lesson-panel {
    position: static;
  }

  .c64-lesson-nav {
    max-height: none;
  }
}

@media (max-width: 720px) {
  .c64-lab-page {
    padding-inline: 0.7rem;
  }

  .c64-machine-panel,
  .c64-lesson-panel {
    padding: 0.65rem;
  }

  .c64-display-frame {
    border-width: 6px;
    border-radius: 9px;
  }

  .c64-machine-heading {
    align-items: flex-start;
    flex-direction: column;
  }

  .c64-command-form {
    grid-template-columns: 1fr;
  }

  .c64-command-form > button {
    width: 100%;
  }

  .c64-control-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .c64-machine-secondary,
  .c64-supporting,
  .c64-related-links {
    grid-template-columns: 1fr;
  }

  .c64-lesson-nav {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  .c64-display-frame,
  .c64-command-form button,
  .c64-control-grid button,
  .c64-special-keys button,
  .c64-lesson-actions button,
  .c64-lesson-tab {
    transition: none !important;
  }

  .c64-crt-enabled .c64-display-frame::after {
    display: none;
  }
}

@media (forced-colors: active) {
  .c64-machine-panel,
  .c64-lesson-panel,
  .c64-reference-card,
  .c64-memory-panel,
  .c64-transcript-panel,
  .c64-program-panel,
  .c64-lesson-block,
  .c64-hint,
  .c64-lesson-complete {
    color: CanvasText;
    border-color: CanvasText;
    background: Canvas;
    box-shadow: none;
  }

  .c64-command-field input,
  .c64-command-form button,
  .c64-control-grid button,
  .c64-special-keys button,
  .c64-lesson-actions button,
  .c64-lesson-tab {
    color: ButtonText;
    border-color: ButtonText;
    background: ButtonFace;
  }

  .c64-crt-enabled .c64-display-frame::after {
    display: none;
  }
}