:root {
  --ink: #19332a;
  --muted: #63766f;
  --green: #176b4d;
  --green-soft: #e3f3eb;
  --blue: #246fa8;
  --orange: #d56525;
  --yellow: #f4bd42;
  --paper: #fffdf8;
  --line: #d5e1dc;
  --bg: #edf5f1;
  font-family: "Segoe UI", system-ui, sans-serif;
  color: var(--ink);
  background: var(--bg);
}
* { box-sizing: border-box; letter-spacing: 0; }
body { min-width: 300px; min-height: 100vh; margin: 0; background: var(--bg); }
button, input, select { font: inherit; letter-spacing: 0; }
button, a { -webkit-tap-highlight-color: transparent; }
.topbar { position: sticky; z-index: 20; top: 0; display: flex; min-height: 66px; align-items: center; justify-content: space-between; gap: 20px; padding: 9px clamp(14px, 4vw, 48px); background: rgba(255,253,248,.96); border-bottom: 1px solid var(--line); backdrop-filter: blur(10px); }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; }
.brand > span { display: grid; width: 39px; height: 39px; place-items: center; color: #fff; background: var(--green); border-radius: 7px; font-weight: 950; }
.brand div { display: grid; }
.brand strong { font-size: .9rem; }
.brand small { color: var(--muted); font-size: .68rem; }
.topbar nav { display: flex; gap: 16px; }
.topbar nav a { color: var(--green); font-size: .75rem; font-weight: 850; text-decoration: none; }
main { width: min(1280px, calc(100% - 28px)); margin: 0 auto; padding: 20px 0 54px; }
.studio-hero { position: relative; min-height: 240px; overflow: hidden; border-radius: 8px; background: #174e65; }
.studio-hero img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; object-position: center 46%; }
.hero-shade { position: absolute; inset: 0; background: linear-gradient(90deg, rgba(10,48,37,.92), rgba(10,48,37,.54) 56%, rgba(10,48,37,.12)); }
.hero-copy { position: relative; z-index: 1; display: grid; align-content: center; min-height: 240px; max-width: 710px; padding: clamp(24px, 5vw, 54px); color: #fff; }
.hero-copy p { margin: 0 0 7px; color: #f8d982; font-size: .75rem; font-weight: 900; text-transform: uppercase; }
.hero-copy h1 { margin: 0; font-size: clamp(2rem, 5vw, 4rem); line-height: 1; }
.hero-copy span { max-width: 620px; margin-top: 12px; color: rgba(255,255,255,.88); line-height: 1.5; }
.studio-shell { display: grid; grid-template-columns: 270px minmax(0, 1fr); gap: 18px; margin-top: 18px; align-items: start; }
.station-rail, .workspace { min-width: 0; background: var(--paper); border: 1px solid var(--line); border-radius: 8px; }
.station-rail { position: sticky; top: 84px; overflow: hidden; }
.rail-heading { padding: 16px; background: #e8f2ed; border-bottom: 1px solid var(--line); }
.rail-heading p, .workspace-head p { margin: 0; color: var(--green); font-size: .68rem; font-weight: 900; text-transform: uppercase; }
.rail-heading h2 { margin: 3px 0 0; font-size: 1rem; }
.station-list { display: grid; padding: 7px; }
.station-button { display: grid; grid-template-columns: 38px minmax(0,1fr) 18px; align-items: center; gap: 9px; min-width: 0; padding: 9px; color: var(--ink); background: transparent; border: 1px solid transparent; border-radius: 6px; text-align: left; cursor: pointer; }
.station-button:hover, .station-button.active { background: #fff; border-color: #bad4c8; }
.station-button > span { display: grid; width: 38px; height: 38px; place-items: center; background: var(--station-soft); border-radius: 50%; font-size: 1.2rem; }
.station-button div { display: grid; min-width: 0; gap: 2px; }
.station-button strong { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: .75rem; }
.station-button small { color: var(--muted); font-size: .62rem; }
.station-button i { color: var(--muted); font-size: 1.1rem; font-style: normal; }
.workspace { overflow: hidden; }
.workspace-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 20px; padding: 20px; border-bottom: 1px solid var(--line); }
.workspace-head h2 { margin: 4px 0 5px; font-size: clamp(1.45rem, 3vw, 2.2rem); line-height: 1.05; }
.workspace-head > div > span { display: block; max-width: 760px; color: var(--muted); font-size: .75rem; line-height: 1.45; }
.phase-progress { display: grid; flex: 0 0 84px; justify-items: center; padding: 9px; background: var(--green-soft); border-radius: 7px; }
.phase-progress strong { color: var(--green); font-size: 1.25rem; }
.phase-progress span { color: var(--muted); font-size: .58rem; text-align: center; }
.phase-tabs { display: grid; grid-template-columns: repeat(3, 1fr); border-bottom: 1px solid var(--line); }
.phase-tab { display: flex; min-height: 52px; align-items: center; justify-content: center; gap: 7px; color: var(--muted); background: #f7faf8; border: 0; border-right: 1px solid var(--line); font-size: .78rem; font-weight: 900; cursor: pointer; }
.phase-tab:last-child { border-right: 0; }
.phase-tab.active { color: var(--green); background: #fff; box-shadow: inset 0 -4px var(--green); }
.phase-panel { min-height: 430px; padding: clamp(18px, 4vw, 34px); }
.phase-intro { max-width: 780px; }
.phase-intro > span { color: var(--station); font-size: .7rem; font-weight: 900; text-transform: uppercase; }
.phase-intro h3 { margin: 5px 0 8px; font-size: 1.5rem; }
.phase-intro > p { margin: 0; color: var(--muted); line-height: 1.6; }
.learn-points { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); margin-top: 22px; border: 1px solid var(--line); }
.learn-point { display: grid; grid-template-columns: 36px 1fr; gap: 8px; min-width: 0; padding: 15px; border-right: 1px solid var(--line); }
.learn-point:last-child { border-right: 0; }
.learn-point > span { font-size: 1.5rem; }
.learn-point strong { display: block; font-size: .78rem; }
.learn-point p { margin: 4px 0 0; color: var(--muted); font-size: .7rem; line-height: 1.45; }
.action-row { display: flex; justify-content: flex-end; gap: 8px; margin-top: 20px; }
.button { display: inline-flex; min-height: 42px; align-items: center; justify-content: center; padding: 9px 14px; border-radius: 6px; font-size: .75rem; font-weight: 900; cursor: pointer; }
.button.primary { color: #fff; background: var(--green); border: 1px solid var(--green); }
.button.secondary { color: var(--green); background: #fff; border: 1px solid #a9cabc; }
.button:disabled { cursor: default; opacity: .62; }
.activity-board { display: grid; gap: 18px; }
.board-heading h3 { margin: 0; font-size: 1.35rem; }
.board-heading p { margin: 5px 0 0; color: var(--muted); line-height: 1.5; }
.tile-tray, .slot-row, .word-result, .stream-tabs { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 9px; min-height: 76px; padding: 13px; background: #f3f7f5; border: 1px solid var(--line); border-radius: 7px; }
.activity-tile, .slot, .stream-button { min-height: 44px; padding: 9px 13px; color: var(--ink); background: #fff; border: 2px solid #c4d6cf; border-radius: 6px; font-weight: 850; cursor: pointer; }
.activity-tile.selected, .stream-button.active { color: #fff; background: var(--station); border-color: var(--station); }
.slot { min-width: 130px; color: var(--muted); border-style: dashed; }
.slot.filled { color: var(--ink); background: var(--station-soft); border-style: solid; }
.word-result { min-height: 100px; font-size: 1.2rem; font-weight: 950; }
.stream-panel { padding: 18px; background: #f7faf8; border-left: 4px solid var(--station); }
.stream-panel h4 { margin: 0 0 6px; }
.stream-panel p { margin: 0; color: var(--muted); line-height: 1.5; }
.checklist { display: grid; gap: 8px; padding: 14px; background: #f7faf8; border: 1px solid var(--line); }
.checklist label { display: grid; grid-template-columns: 20px 1fr; align-items: start; gap: 8px; padding: 8px; background: #fff; border: 1px solid #e3ebe7; border-radius: 5px; font-size: .76rem; line-height: 1.4; }
.checklist input { width: 17px; height: 17px; margin: 1px 0 0; accent-color: var(--green); }
.solar-lab { display: grid; grid-template-columns: minmax(220px,.8fr) minmax(0,1fr); gap: 18px; align-items: center; }
.solar-scene { position: relative; display: grid; min-height: 250px; place-items: center; overflow: hidden; background: #dceff8; border: 1px solid #bed5e0; border-radius: 7px; }
.sun { position: absolute; top: 24px; left: 28px; width: 66px; height: 66px; background: var(--yellow); border-radius: 50%; box-shadow: 0 0 calc(var(--light) * 1px) rgba(244,189,66,.88); }
.solar-panel { display: grid; width: 145px; height: 88px; grid-template-columns: repeat(4,1fr); grid-template-rows: repeat(2,1fr); margin-top: 55px; background: #245f91; border: 7px solid #e9eff2; transform: skewY(-7deg); }
.solar-panel i { border: 1px solid #75a8cc; }
.buzzer { position: absolute; right: 32px; bottom: 36px; display: grid; width: 58px; height: 58px; place-items: center; background: #333; border-radius: 50%; color: #fff; font-size: calc(14px + var(--light) * .1px); }
.lab-controls { display: grid; gap: 12px; }
.lab-controls label { font-size: .75rem; font-weight: 850; }
.lab-controls input { width: 100%; accent-color: var(--orange); }
.light-readout { padding: 12px; color: var(--green); background: var(--green-soft); border-left: 4px solid var(--green); font-weight: 850; }
.table-game { display: grid; max-width: 560px; gap: 14px; margin: 0 auto; text-align: center; }
.table-fact { padding: 25px; color: var(--station); background: var(--station-soft); border: 1px solid var(--line); border-radius: 7px; font-size: 2.4rem; font-weight: 950; }
.answer-row { display: grid; grid-template-columns: 1fr auto; gap: 8px; }
.answer-row input, .confirm-fields input { min-width: 0; min-height: 44px; padding: 8px 10px; color: var(--ink); background: #fff; border: 1px solid #b9cec5; border-radius: 6px; }
.score-line { color: var(--muted); font-size: .75rem; font-weight: 800; }
.confirm-fields { display: grid; grid-template-columns: repeat(3,1fr); gap: 10px; }
.confirm-fields label { display: grid; gap: 5px; font-size: .68rem; font-weight: 850; }
.warning { padding: 13px; color: #7f421f; background: #fff1e7; border-left: 4px solid var(--orange); font-size: .75rem; line-height: 1.5; }
.feedback { min-height: 50px; margin: 0; padding: 12px; color: var(--muted); background: #f7faf8; border-left: 4px solid var(--station); line-height: 1.5; }
.feedback.success { color: #15543e; background: var(--green-soft); }
.status-message { min-height: 20px; margin: 0; padding: 0 24px 18px; color: var(--green); font-size: .72rem; font-weight: 850; }
button:focus-visible, a:focus-visible, input:focus-visible { outline: 3px solid var(--yellow); outline-offset: 2px; }
@media (max-width: 850px) {
  .studio-shell { grid-template-columns: 1fr; }
  .station-rail { position: static; }
  .station-list { grid-template-columns: repeat(2,minmax(0,1fr)); }
  .learn-points { grid-template-columns: 1fr; }
  .learn-point { border-right: 0; border-bottom: 1px solid var(--line); }
  .learn-point:last-child { border-bottom: 0; }
  .solar-lab { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  main { width: min(100% - 16px,1280px); padding-top: 8px; }
  .topbar nav a:first-child { display: none; }
  .studio-hero, .hero-copy { min-height: 210px; }
  .station-list { grid-template-columns: 1fr; }
  .workspace-head { align-items: flex-start; flex-direction: column; }
  .phase-progress { grid-template-columns: auto auto; align-items: center; gap: 5px; }
  .phase-tabs span { display: none; }
  .confirm-fields { grid-template-columns: 1fr; }
  .answer-row { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation: none !important; transition: none !important; } }