:root {
  color-scheme: dark;
  --bg: #080d0b;
  --panel: #111a15;
  --line: #25382d;
  --green: #99ff94;
  --text: #edf7ef;
  --muted: #a3b5a9;
  --blue: #8cceef;
  --orange: #ffc18b;
  --red: #ff9c9c;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
  background:
    radial-gradient(ellipse at 25% 0, #19352666, transparent 650px), var(--bg);
  color: var(--text);
  font:
    15px/1.65 system-ui,
    -apple-system,
    "PingFang SC",
    "Microsoft YaHei",
    sans-serif;
}
button,
input,
textarea,
select {
  font: inherit;
}
button,
a,
input,
textarea,
select {
  outline-offset: 4px;
}
button:focus-visible,
a:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  outline: 2px solid var(--green);
}
button,
.button {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #18251c;
  color: var(--text);
  padding: 10px 16px;
  min-height: 44px;
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
}
button:hover,
.button:hover {
  border-color: #7dab87;
}
button:disabled {
  opacity: 0.42;
  cursor: not-allowed;
}
.primary {
  background: var(--green);
  color: #102416;
  border-color: transparent;
  font-weight: 750;
}
.quiet {
  background: transparent;
  color: var(--muted);
}
a {
  color: var(--green);
}
.topbar {
  min-height: 74px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 14px 28px;
  border-bottom: 1px solid var(--line);
  background: #0a110ee8;
}
.brand {
  display: flex;
  gap: 12px;
  align-items: center;
  text-decoration: none;
  color: var(--text);
  font-size: 18px;
  white-space: nowrap;
}
.brand b {
  color: var(--green);
  font-weight: 550;
}
.brand-mark {
  background: var(--green);
  color: #14271a;
  border-radius: 10px;
  width: 37px;
  height: 37px;
  display: grid;
  place-items: center;
  font-weight: 900;
}
.top-actions,
.actions,
.chips {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}
#save-state {
  font-size: 13px;
  color: var(--muted);
}
.shell {
  max-width: 1150px;
  margin: 0 auto;
  padding: 40px 28px 100px;
}
.narrow {
  max-width: 870px;
}
.hero {
  padding-top: clamp(65px, 10vh, 130px);
  text-align: center;
}
.eyebrow {
  color: var(--green);
  font-size: 13px;
  letter-spacing: 0.14em;
  margin-bottom: 14px;
}
.hero h1 {
  font-size: clamp(38px, 5.8vw, 68px);
  letter-spacing: -0.045em;
  line-height: 1.15;
  margin: 0 0 24px;
}
.hero h1 span {
  color: var(--green);
}
h1,
h2,
h3 {
  line-height: 1.3;
  overflow-wrap: anywhere;
}
h2 {
  font-size: clamp(25px, 3vw, 36px);
  margin: 14px 0;
}
h3 {
  font-size: 19px;
  margin: 10px 0;
}
.lead {
  color: #b7cbbd;
  max-width: 630px;
  margin: 0 auto 26px;
  font-size: 17px;
}
.idea {
  display: flex;
  gap: 12px;
  padding: 10px;
  border: 1px solid #598061;
  background: #111d15;
  border-radius: 18px;
  box-shadow: 0 18px 70px #0004;
}
.idea textarea {
  border: 0;
  min-height: 90px;
}
.idea button {
  align-self: stretch;
  min-width: 155px;
}
.hero-footer {
  margin-top: 32px;
  display: flex;
  justify-content: center;
  gap: 26px;
  color: var(--muted);
  font-size: 14px;
}
.examples {
  justify-content: center;
  margin-top: 16px;
}
.examples button {
  font-size: 14px;
  border-radius: 24px;
  background: transparent;
}
textarea,
input,
select {
  width: 100%;
  background: #0b140f;
  color: var(--text);
  border: 1px solid #3a5141;
  border-radius: 11px;
  padding: 12px;
  min-height: 46px;
}
textarea {
  resize: vertical;
  min-height: 100px;
}
label {
  display: block;
  color: #c0d3c6;
  font-size: 14px;
  margin: 16px 0 7px;
}
label:has(input[type="checkbox"]) {
  display: flex;
  gap: 10px;
  align-items: start;
}
input[type="checkbox"] {
  width: 18px;
  height: 18px;
  min-height: 18px;
  accent-color: var(--green);
  margin-top: 4px;
  flex-shrink: 0;
}
.card {
  background: linear-gradient(135deg, #16231a, #0e1711);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 26px;
  margin: 20px 0;
}
.muted {
  color: var(--muted);
}
.small {
  font-size: 13px;
}
.tag {
  display: inline-block;
  background: #203426;
  color: #b6e4be;
  padding: 3px 10px;
  font-size: 13px;
  border-radius: 7px;
}
.tag.warning {
  color: var(--orange);
  background: #51382144;
}
.tag.block {
  color: var(--red);
  background: #51262666;
}
.tag.info {
  color: var(--blue);
  background: #1e3f5166;
}
.choices {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}
.choice {
  text-align: left;
  display: block;
  padding: 17px;
}
.choice strong,
.choice span {
  display: block;
}
.choice span {
  font-size: 14px;
  color: var(--muted);
  margin-top: 4px;
}
.choice[aria-pressed="true"] {
  border-color: var(--green);
  background: #223b27;
}
.between {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}
.notice {
  border-left: 3px solid var(--blue);
  background: #172d2544;
  border-radius: 0 10px 10px 0;
  padding: 14px 18px;
  margin: 18px 0;
  overflow-wrap: anywhere;
}
.notice.warning {
  border-color: var(--orange);
  background: #38271544;
}
.notice.block,
.error {
  border-color: var(--red);
  background: #42232355;
  color: #ffd2d2;
}
.error {
  padding: 14px 18px;
  border-left: 3px solid var(--red);
  margin: 16px 0;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}
.progress-panel {
  margin: 20px 0;
  border: 1px solid #426e4b;
  padding: 20px;
  border-radius: 14px;
  background: #172c1d;
}
.progress-panel progress {
  width: 100%;
  height: 5px;
  accent-color: var(--green);
}
.architecture {
  display: flex;
  gap: 12px;
  align-items: stretch;
  overflow: auto;
  margin: 24px 0;
}
.node {
  flex: 1;
  min-width: 150px;
  text-align: center;
  background: #14231a;
  border: 1px solid #304c38;
  border-radius: 16px;
  padding: 18px;
}
.node strong,
.node small {
  display: block;
}
.node small {
  font-size: 13px;
  color: var(--muted);
}
.arrow {
  align-self: center;
  color: var(--green);
}
.parts {
  display: grid;
  gap: 12px;
}
.part {
  display: grid;
  grid-template-columns: 76px minmax(0, 1fr) auto;
  gap: 15px;
  align-items: center;
  border-bottom: 1px solid var(--line);
  padding: 14px 0;
}
.part img,
.part-icon {
  width: 76px;
  height: 70px;
  object-fit: contain;
  background: #e5ede5;
  border-radius: 12px;
  padding: 6px;
}
.part-icon {
  display: grid;
  place-items: center;
  background: #20352a;
  color: var(--green);
  font-size: 28px;
}
.part small {
  display: block;
  color: var(--muted);
}
.part select {
  width: 135px;
}
.studio-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 230px;
  gap: 34px;
}
.task-card h2 {
  margin: 20px 0;
}
.task-card .action {
  font-size: 19px;
  color: #cfe2d5;
}
.expected {
  border-left: 3px solid var(--blue);
  padding: 14px 18px;
  background: #162b2566;
  margin: 22px 0;
}
.expected strong {
  display: block;
  color: var(--blue);
}
.roadmap {
  display: grid;
  gap: 7px;
}
.roadmap button {
  justify-content: space-between;
  text-align: left;
  font-size: 14px;
  background: transparent;
}
.roadmap button.current {
  border-color: var(--green);
  color: var(--green);
}
.aside {
  padding-top: 26px;
  color: var(--muted);
}
.aside .card {
  padding: 18px;
  box-shadow: none;
}
details {
  border-top: 1px solid var(--line);
  padding: 15px 0;
  margin-top: 12px;
}
summary {
  cursor: pointer;
  color: #bbd1c1;
  min-height: 30px;
}
.code {
  font:
    14px/1.7 ui-monospace,
    Consolas,
    monospace;
  min-height: 310px;
  white-space: pre;
  tab-size: 2;
}
.log,
pre {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  background: #080e0a;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 16px;
  font:
    13px/1.6 ui-monospace,
    monospace;
  max-height: 330px;
  overflow: auto;
}
.diagram {
  padding: 22px;
  background: #0a150e;
  border: 1px solid #2a4933;
  border-radius: 16px;
}
.wire {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 14px;
  align-items: center;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}
.wire span:nth-child(2) {
  color: var(--green);
  font-size: 24px;
}
.wire small {
  display: block;
  color: var(--muted);
}
.task-images {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  justify-content: center;
  margin: 20px 0;
}
.task-images figure {
  margin: 0;
  flex: 1;
  min-width: 130px;
  max-width: 260px;
  text-align: center;
}
.task-images img {
  width: 100%;
  height: 180px;
  object-fit: contain;
  background: #dfe9e1;
  border-radius: 14px;
  padding: 12px;
}
.task-images figcaption {
  color: var(--muted);
  font-size: 13px;
}
dialog {
  max-width: 790px;
  width: calc(100% - 32px);
  max-height: 88vh;
  color: var(--text);
  background: #101b14;
  border: 1px solid #47604e;
  border-radius: 22px;
  padding: 26px;
  overflow: auto;
}
dialog::backdrop {
  background: #000a;
  backdrop-filter: blur(5px);
}
dialog h2 {
  font-size: 26px;
}
.dialog-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
}
.reply {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  padding: 16px;
  border-left: 2px solid var(--green);
  margin: 16px 0;
  background: #1b2e2055;
}
.student {
  border-color: var(--blue);
  background: #16263044;
}
.zones {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  background: #132b1b;
  border: 1px dashed var(--green);
  padding: 24px;
  border-radius: 30px;
}
.zone {
  padding: 18px;
  border: 1px solid #547a5c;
  border-radius: 12px;
  text-align: center;
}
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 14px;
}
.project-grid .card {
  margin: 0;
}
.metric {
  font-size: 32px;
  color: var(--green);
}
.evidence-item {
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}
.evidence-item p {
  margin: 6px 0;
}
.two {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}
#toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  background: #25432d;
  color: #e9ffea;
  max-width: calc(100% - 28px);
  padding: 13px 22px;
  border-radius: 12px;
  box-shadow: 0 10px 50px #0008;
  display: none;
  z-index: 100;
}
#toast.show {
  display: block;
}
.safe-source {
  font-size: 12px;
  color: var(--muted);
}
.result-count {
  display: flex;
  gap: 30px;
}
.footer-actions {
  margin-top: 26px;
}
.task-progress {
  width: 100%;
  height: 5px;
  accent-color: var(--green);
}
@media (max-width: 900px) {
  .studio-layout {
    grid-template-columns: 1fr;
  }
  .aside {
    padding-top: 0;
  }
  .aside .roadmap {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .top-actions > a {
    display: none;
  }
  .shell {
    padding: 28px 20px 70px;
  }
  .brand {
    font-size: 15px;
  }
}
@media (max-width: 570px) {
  .topbar {
    padding: 12px 14px;
    gap: 8px;
    align-items: flex-start;
  }
  .brand span:last-child {
    white-space: normal;
    max-width: 135px;
    line-height: 1.25;
  }
  .top-actions {
    gap: 5px;
    justify-content: flex-end;
  }
  .top-actions #save-state {
    font-size: 11px;
  }
  .top-actions button {
    padding: 8px 10px;
  }
  .hero {
    padding-top: 50px;
  }
  .idea {
    display: block;
  }
  .idea button {
    width: 100%;
    margin-top: 8px;
  }
  .hero-footer {
    display: block;
  }
  .choices,
  .two {
    grid-template-columns: 1fr;
  }
  .card {
    padding: 20px;
  }
  .part {
    grid-template-columns: 55px 1fr;
    gap: 12px;
  }
  .part img,
  .part-icon {
    width: 55px;
    height: 55px;
  }
  .part select {
    grid-column: 2;
    width: 100%;
  }
  .architecture {
    flex-direction: column;
  }
  .node {
    min-width: 0;
  }
  .arrow {
    transform: rotate(90deg);
  }
  .actions > * {
    flex-grow: 1;
  }
  .code {
    font-size: 13px;
  }
  .wire {
    grid-template-columns: 1fr auto 1fr;
    font-size: 13px;
    gap: 8px;
  }
  .task-images img {
    height: 130px;
  }
  .aside .roadmap {
    grid-template-columns: 1fr;
  }
  .top-actions .quiet {
    display: none;
  }
}
/* Beginner guidance: one action, a readable illustration, then the next action. */
.part-picture {
  width: 112px;
  height: 100px;
  padding: 8px;
  flex-shrink: 0;
  background: #e0e9dc;
  border-radius: 14px;
}
.part {
  grid-template-columns: 112px minmax(0, 1fr) auto;
}
.part-picture img {
  width: 100%;
  height: 100%;
  padding: 0;
  background: none;
}
.part-picture img,
.part-illustration {
  width: 100%;
  height: 100%;
  object-fit: contain;
}
.part-detail {
  max-width: 640px;
  margin: auto;
}
.part-detail > img,
.part-detail > .part-illustration,
.board-reference {
  display: block;
  max-height: 270px;
  width: 100%;
  object-fit: contain;
  background: #e0e9dc;
  padding: 20px;
  border-radius: 16px;
}
.part details {
  border: 0;
  padding: 8px 0;
  margin: 0;
}
.part summary {
  font-size: 14px;
}
.studio-layout {
  display: block;
  max-width: 1000px;
  margin: auto;
}
.studio-layout .aside {
  border: 0;
  margin-top: 28px;
  padding: 0;
}
.studio-layout .aside > h3 {
  display: none;
}
.task-parent {
  color: #a9b8ad;
  font-size: 14px;
  margin-bottom: 10px;
}
.prepare-guide {
  padding: 16px 0;
}
.prepare-guide label {
  display: block;
  margin: 22px 0;
  line-height: 1.7;
}
.wire-drawing {
  margin: 24px 0;
  padding: 20px;
  background: #091e17;
  border-radius: 20px;
}
.wire-drawing figcaption {
  color: #b8fb97;
  font-size: 15px;
  margin-bottom: 16px;
}
.wire-drawing svg,
.prepare-guide svg {
  width: 100%;
  height: auto;
}
.secondary-conditions {
  border: 0;
}
.secondary-conditions small {
  display: block;
  margin-top: 8px;
}
.mentor-launcher {
  position: fixed;
  bottom: 20px;
  right: 24px;
  z-index: 15;
  background: #bdff85;
  color: #122013;
  font-weight: 700;
  box-shadow: 0 5px 30px #0007;
  border: 0;
  border-radius: 40px;
  min-height: 52px;
}
main {
  padding-bottom: 100px;
}
.result-notes {
  margin-top: 24px;
}
.guide-subtitle {
  font-size: 15px;
  color: #bdc9c0;
}
@media (max-width: 640px) {
  .part {
    grid-template-columns: 88px minmax(0, 1fr);
    flex-wrap: wrap;
    gap: 14px;
  }
  .part-picture {
    width: 88px;
    height: 80px;
  }
  .part > div {
    flex: 1;
    min-width: 150px;
  }
  .part > label {
    width: 100%;
    grid-column: 1 / -1;
    display: flex;
    align-items: center;
    gap: 16px;
  }
  .part > label select {
    flex: 1;
    min-width: 120px;
  }
  .mentor-launcher {
    right: 16px;
    bottom: 14px;
    font-size: 14px;
  }
  .wire-drawing {
    padding: 12px;
    margin-inline: -8px;
  }
  .studio-layout .aside {
    margin-top: 16px;
  }
}
.circuit-workbench {
  margin: 24px 0;
  border: 1px solid #385641;
  border-radius: 18px;
  overflow: hidden;
  background: #0b1912;
}
.circuit-toolbar {
  padding: 16px 18px;
  display: flex;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
  border-bottom: 1px solid #314c3b;
}
.circuit-toolbar strong {
  display: block;
  font-size: 18px;
  margin-bottom: 8px;
}
.circuit-toolbar .actions {
  gap: 6px;
}
.circuit-toolbar button {
  padding: 8px 12px;
  min-height: 40px;
}
.circuit-viewport {
  overflow: auto;
  max-height: none;
  overscroll-behavior: contain;
}
.circuit-canvas {
  display: block;
  min-width: 0;
  height: auto;
  font-family: system-ui, sans-serif;
}
.circuit-canvas [role="button"] {
  cursor: pointer;
  outline: none;
}
.circuit-canvas [role="button"]:focus-visible {
  filter: drop-shadow(0 0 4px #cfff7b);
}
.circuit-wire {
  transition: opacity 0.15s;
}
.circuit-wire.dimmed {
  opacity: 0.18;
}
.circuit-wire:hover,
.circuit-wire:focus-visible {
  opacity: 1;
}
.circuit-wire.selected .wire-color {
  filter: drop-shadow(0 0 4px currentColor);
}
.circuit-inspector {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 20px;
  background: #173322;
  border-top: 1px solid #426048;
}
.circuit-inspector > div {
  flex: 1;
  min-width: 0;
}
.circuit-inspector p {
  margin: 8px 0;
}
.circuit-inspector small {
  color: #c9d8ca;
}
.wire-swatch {
  display: inline-block;
  flex: 0 0 22px;
  width: 22px;
  height: 5px;
  margin-top: 10px;
  border-radius: 4px;
}
.circuit-hint {
  margin: 0;
  padding: 18px;
  color: #d1e2d4;
}
.circuit-legend {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  padding: 12px 18px;
  font-size: 13px;
  color: #a9c4b4;
}
.circuit-index {
  margin: 0;
  padding: 14px 18px;
}
.circuit-line-list {
  display: grid;
  gap: 8px;
  margin-top: 14px;
}
.circuit-line-list button {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  text-align: left;
}
.circuit-line-list button span:nth-child(2) {
  flex: 1;
}
.circuit-line-list button[aria-pressed="true"] {
  border-color: #a6ff93;
  background: #22442a;
}
.diagram-next {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.diagram-next p {
  color: #b5ccbb;
}
dialog:has(.circuit-workbench) {
  width: min(96vw, 1400px);
  max-width: 96vw;
}
@media (max-width: 650px) {
  .circuit-toolbar {
    padding: 12px;
  }
  .circuit-toolbar .actions {
    flex-wrap: wrap;
  }
  .circuit-inspector {
    flex-wrap: wrap;
    padding: 14px;
  }
  .circuit-inspector button {
    margin-left: 34px;
  }
  .circuit-line-list button {
    flex-wrap: wrap;
  }
  .circuit-viewport {
    max-height: none;
  }
  .circuit-workbench {
    margin: 18px -8px;
  }
}
 .chips button[aria-pressed="true"] { border-color: var(--accent, #b6ff83); background: #294b34; box-shadow: inset 0 0 0 1px #b6ff83; }
 .reference-links { display:flex; flex-wrap:wrap; gap:12px; margin:12px 0; }
 .photo-preview { max-width:100%; max-height:180px; object-fit:contain; border-radius:10px; }