/* ── Geneva Mechanism Simulator ──────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:        #0d1117;
  --surface:   #161b27;
  --surface2:  #1f2535;
  --border:    #2a3050;
  --accent:    #7c3aed;
  --accent-lo: rgba(124,58,237,.22);
  --green:     #3ddc84;
  --red:       #ff5555;
  --gold:      #f5c842;
  --text:      #dde3f0;
  --text-dim:  #6b7a99;
  --font:      'Segoe UI', system-ui, sans-serif;
  --mono:      'Courier New', monospace;
  --radius:    12px;
  --driver-color:  #7c3aed;
  --wheel-color:   #f5c842;
  --pin-color:     #ff8a65;
  --lock-color:    #8899aa;
}

body { background: var(--bg); color: var(--text); font-family: var(--font); min-height: 100vh; padding: 0 16px; }
#app { max-width: 980px; margin: 0 auto; display: flex; flex-direction: column; gap: 14px; }

header { text-align: center; padding: 4px 0; }
header h1 {
  font-size: 1.8rem; font-weight: 700;
  background: linear-gradient(120deg, #7c3aed 0%, #a78bfa 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.subtitle { color: var(--text-dim); font-size: 0.85rem; margin-top: 3px; }

.controls-bar { display: flex; flex-wrap: wrap; align-items: center; gap: 14px; padding: 12px 16px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); }
.ctrl-group { display: flex; align-items: center; gap: 8px; }
.ctrl-label { font-size: 0.72rem; text-transform: uppercase; letter-spacing: .06em; color: var(--text-dim); white-space: nowrap; }
.pill-tabs { display: flex; background: var(--bg); border-radius: 8px; padding: 3px; gap: 2px; }
.pill { padding: 8px 14px; min-height: 36px; border: none; background: transparent; color: var(--text-dim); border-radius: 6px; cursor: pointer; font-size: 0.81rem; transition: background .18s, color .18s, box-shadow .18s; }
.pill.active { background: var(--accent); color: #fff; box-shadow: 0 0 12px var(--accent-lo); }
.pill:hover:not(.active) { background: var(--surface2); color: var(--text); }

.canvas-card { width: 100%; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 8px; position: relative; overflow-x: clip; }
.canvas-card canvas { display: block; width: 100%; height: auto; cursor: pointer; touch-action: pan-y; }

.btn { padding: 8px 18px; border: none; border-radius: 8px; cursor: pointer; font-size: 0.84rem; font-weight: 600; transition: filter .18s, box-shadow .18s, opacity .18s; }
.btn:disabled { opacity: 0.38; cursor: not-allowed; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:not(:disabled):hover { filter: brightness(1.12); box-shadow: 0 0 12px var(--accent-lo); }
.btn-ghost { background: var(--surface2); color: var(--text); border: 1px solid var(--border); }
.btn-ghost:hover { background: var(--border); }

.sim-controls { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 10px 12px; display: flex; flex-direction: column; gap: 10px; }
.sim-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; }
.sim-slider-group { display: flex; align-items: center; gap: 6px; padding: 5px 8px; background: var(--bg); border: 1px solid var(--border); border-radius: 8px; min-width: 0; }
.sim-slider-label { font-size: 0.68rem; font-weight: 700; color: var(--text-dim); white-space: nowrap; }
.sim-slider { flex: 1; min-width: 0; -webkit-appearance: none; appearance: none; height: 6px; background: var(--surface2); border-radius: 3px; outline: none; }
.sim-slider::-webkit-slider-thumb { -webkit-appearance: none; width: 24px; height: 24px; border-radius: 50%; background: var(--accent); cursor: pointer; box-shadow: 0 0 8px var(--accent-lo); }
.sim-slider::-moz-range-thumb { width: 24px; height: 24px; border: none; border-radius: 50%; background: var(--accent); cursor: pointer; }
.sim-slider-input { width: 46px; padding: 4px 4px; border: 1px solid var(--border); border-radius: 5px; background: var(--surface2); color: var(--accent); font-family: var(--mono); font-size: 0.78rem; font-weight: 700; text-align: center; outline: none; -moz-appearance: textfield; }
.sim-slider-input::-webkit-inner-spin-button, .sim-slider-input::-webkit-outer-spin-button { -webkit-appearance: none; margin: 0; }
.sim-slider-input:focus { border-color: var(--accent); }
.sim-slider-unit { font-size: 0.7rem; color: var(--text-dim); white-space: nowrap; }

.preset-row { display: flex; gap: 6px; flex-wrap: wrap; }
.preset-btn { padding: 9px 14px; min-height: 38px; border: 2px solid var(--border); border-radius: 8px; background: var(--surface2); color: var(--text-dim); font-size: 0.78rem; font-weight: 700; cursor: pointer; transition: border-color .18s, color .18s, background .18s; }
.preset-btn:hover { border-color: var(--accent); color: var(--text); }
.preset-btn.active { border-color: var(--accent); color: #fff; background: rgba(124,58,237,.18); }

.readout-row { display: grid; grid-template-columns: repeat(auto-fill, minmax(110px, 1fr)); gap: 8px; }
.readout-card { background: var(--bg); border: 1px solid var(--border); border-radius: 8px; padding: 8px 12px; text-align: center; }
.readout-label { font-size: 0.62rem; text-transform: uppercase; letter-spacing: .07em; color: var(--text-dim); margin-bottom: 3px; }
.readout-val { font-family: var(--mono); font-size: 1.05rem; font-weight: 700; color: var(--accent); }

.item-selector { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 16px; }
.is-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(155px, 1fr)); gap: 8px; margin-top: 10px; }
.is-btn { padding: 10px 14px; border: 2px solid var(--border); border-radius: 10px; background: var(--surface2); color: var(--text-dim); font-size: 0.82rem; font-weight: 600; cursor: pointer; text-align: left; transition: border-color .18s, color .18s, background .18s, box-shadow .18s; }
.is-btn:hover { border-color: rgba(124,58,237,.45); color: var(--text); }
.is-btn.active { border-color: var(--accent); color: #fff; background: rgba(124,58,237,.15); box-shadow: 0 0 14px var(--accent-lo); }
.is-btn-name { display: block; font-size: 0.82rem; font-weight: 700; }
.is-btn-sym  { display: block; font-size: 0.68rem; color: var(--accent); margin-top: 2px; font-family: var(--mono); }

.item-info { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px 18px; display: flex; flex-direction: column; gap: 8px; }
.ii-top { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.ii-name { font-size: 1.15rem; font-weight: 800; color: var(--text); }
.ii-cat-badge { font-size: 0.62rem; font-weight: 700; text-transform: uppercase; letter-spacing: .07em; padding: 3px 10px; border-radius: 20px; background: var(--accent-lo); color: var(--accent); }
.ii-desc { font-size: 0.85rem; color: var(--text-dim); line-height: 1.65; }

.formula-box { background: var(--bg); border: 1px solid var(--border); border-radius: 8px; padding: 10px 14px; display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.fb-formula { font-family: var(--mono); font-size: 1.1rem; font-weight: 700; color: var(--accent); }
.fb-unit { font-size: 0.78rem; color: var(--text-dim); }

.example-box { background: var(--surface2); border: 1px solid var(--border); border-radius: 8px; padding: 12px 14px; }
.example-box h4 { font-size: 0.72rem; text-transform: uppercase; letter-spacing: .08em; color: var(--accent); margin-bottom: 8px; }
.example-box .ex-problem { font-size: 0.84rem; color: var(--text); margin-bottom: 8px; line-height: 1.6; }
.example-box .ex-step { font-size: 0.8rem; color: var(--text-dim); line-height: 1.6; padding: 2px 0; }
.example-box .ex-step strong { color: var(--green); font-family: var(--mono); }

.practice-panel { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px 18px; }
.pp-prompt { font-size: 0.92rem; font-weight: 600; color: var(--text); margin-bottom: 14px; line-height: 1.6; }
.pp-input-row { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.pp-input { flex: 1; min-width: 120px; max-width: 220px; padding: 10px 14px; border: 2px solid var(--border); border-radius: 8px; background: var(--bg); color: var(--text); font-family: var(--mono); font-size: 1rem; font-weight: 700; transition: border-color .18s; }
.pp-input:focus { outline: none; border-color: var(--accent); }
.pp-unit { font-size: 0.88rem; color: var(--text-dim); font-weight: 600; }
.pp-bottom { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; margin-top: 14px; }
.feedback { font-size: 0.88rem; font-weight: 600; }
.feedback.ok  { color: var(--green); }
.feedback.err { color: var(--red); }

.solution-panel { background: var(--surface2); border: 1px solid var(--border); border-radius: 8px; padding: 14px 16px; margin-top: 12px; }
.solution-panel h4 { font-size: 0.72rem; text-transform: uppercase; letter-spacing: .08em; color: var(--accent); margin-bottom: 8px; }
.sol-step { font-size: 0.82rem; color: var(--text-dim); line-height: 1.7; padding: 2px 0; }
.sol-step strong { color: var(--green); font-family: var(--mono); }

.practice-bar { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; padding: 12px 16px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); }
.pbar-score { font-size: 0.84rem; color: var(--text-dim); margin-left: auto; white-space: nowrap; }
.pbar-score span { color: var(--text); font-weight: 700; }

.question-panel { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px 18px; }
.qp-prompt { font-size: 0.88rem; font-weight: 600; color: var(--text); margin-bottom: 12px; line-height: 1.6; }
.answer-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.answer-btn { padding: 14px 16px; border: 2px solid var(--border); border-radius: 10px; background: var(--surface2); color: var(--text); font-size: 0.88rem; font-weight: 600; cursor: pointer; text-align: center; transition: border-color .18s, background .18s, color .18s, transform .12s; }
.answer-btn:hover:not(.locked) { border-color: var(--accent); background: rgba(124,58,237,.06); }
.answer-btn.correct { border-color: var(--green); background: rgba(61,220,132,.12); color: var(--green); }
.answer-btn.wrong { border-color: var(--red); background: rgba(255,85,85,.08); color: var(--red); }
.answer-btn.locked { cursor: default; opacity: 0.6; }
.answer-btn.correct.locked { opacity: 1; }

.quiz-input-row { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 10px; }
.qi-input { flex: 1; min-width: 120px; max-width: 200px; padding: 10px 14px; border: 2px solid var(--border); border-radius: 8px; background: var(--bg); color: var(--text); font-family: var(--mono); font-size: 1rem; font-weight: 700; transition: border-color .18s; }
.qi-input:focus { outline: none; border-color: var(--accent); }
.qi-unit { font-size: 0.84rem; color: var(--text-dim); font-weight: 600; }

.quiz-bar { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; padding: 12px 16px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); }
.qbar-counter { display: flex; align-items: baseline; gap: 3px; background: var(--bg); border: 1px solid var(--border); border-radius: 8px; padding: 4px 12px; }
.qbar-q-label { font-size: 0.7rem; font-weight: 700; color: var(--accent); text-transform: uppercase; letter-spacing: .08em; }
.qbar-q-num { font-family: var(--mono); font-size: 1.3rem; font-weight: 700; color: var(--text); line-height: 1; }
.qbar-q-sep { font-size: 0.82rem; color: var(--text-dim); }
.qbar-q-total { font-family: var(--mono); font-size: 0.88rem; color: var(--text-dim); }
.quiz-feedback { font-size: 0.88rem; font-weight: 600; }
.quiz-feedback.ok  { color: var(--green); }
.quiz-feedback.err { color: var(--red); }

.quiz-result { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px 22px; display: flex; flex-direction: column; gap: 14px; }
.qr-header { display: flex; align-items: flex-start; justify-content: space-between; }
.qr-title-wrap { display: flex; flex-direction: column; gap: 5px; }
.qr-title  { font-size: 1.1rem; font-weight: 700; color: var(--text); }
.qr-stars  { font-size: 1.2rem; letter-spacing: 3px; }
.qr-score-wrap { text-align: right; }
.qr-score { font-family: var(--mono); font-size: 2.2rem; font-weight: 700; line-height: 1; text-shadow: 0 0 14px currentColor; }
.qr-score.perfect { color: var(--gold); }
.qr-score.good { color: var(--green); }
.qr-score.poor { color: var(--red); }
.qr-verdict { font-size: 0.72rem; color: var(--text-dim); margin-top: 3px; }
.qr-rows { display: flex; flex-direction: column; gap: 7px; }
.qr-row { display: grid; grid-template-columns: 30px 1fr 26px; align-items: center; gap: 10px; background: var(--surface2); border: 1px solid var(--border); border-left-width: 3px; border-radius: 8px; padding: 9px 12px; }
.qr-row.ok  { border-left-color: var(--green); }
.qr-row.err { border-left-color: var(--red); }
.qr-qnum { font-size: 0.72rem; font-weight: 700; color: var(--accent); }
.qr-detail { font-size: 0.78rem; color: var(--text-dim); }
.qr-detail strong { color: var(--text); }
.qr-mark { text-align: right; font-size: 1rem; font-weight: 700; }
.qr-row.ok .qr-mark { color: var(--green); }
.qr-row.err .qr-mark { color: var(--red); }

/* Hint bar */
.hint-bar { display: flex; align-items: center; gap: 10px; padding: 10px 16px; background: rgba(124,58,237,0.1); border: 1px solid rgba(124,58,237,0.3); border-radius: var(--radius); font-size: 0.78rem; color: var(--text-dim); }
.hint-bar span { flex: 1; }
.hint-close { background: none; border: none; color: var(--text-dim); font-size: 1.2rem; cursor: pointer; padding: 4px 8px; line-height: 1; }
.hint-close:hover { color: var(--text); }

/* Context menu */
.ctx-menu { position: fixed; z-index: 1000; background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 4px; box-shadow: 0 8px 24px rgba(0,0,0,.4); min-width: 150px; }
.ctx-item { display: block; width: 100%; padding: 9px 14px; border: none; background: none; color: var(--text); font-size: 0.82rem; text-align: left; cursor: pointer; border-radius: 5px; }
.ctx-item:hover { background: var(--accent-lo); color: #fff; }

.seo-article { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px 24px; line-height: 1.7; }
.seo-article h2 { font-size: 1.25rem; color: var(--text); margin-bottom: 12px; }
.seo-article h3 { font-size: 1.05rem; color: var(--accent); margin: 16px 0 6px; }
.seo-article p { font-size: 0.88rem; color: var(--text-dim); margin-bottom: 10px; }

@media (max-width: 768px) {
  .answer-grid { grid-template-columns: 1fr 1fr; }
  .is-grid { grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); }
  .controls-bar { gap: 10px; }
  .readout-row { grid-template-columns: repeat(2, 1fr); }
  .sim-row { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 500px) {
  header h1 { font-size: 1.4rem; }
  .subtitle  { font-size: 0.78rem; }
  .controls-bar { padding: 10px 12px; gap: 8px; }
  .pill { padding: 5px 10px; font-size: 0.76rem; }
  .answer-grid { grid-template-columns: 1fr; }
  .is-grid { grid-template-columns: 1fr 1fr; }
  .readout-row { grid-template-columns: 1fr 1fr; }
  .sim-row { grid-template-columns: 1fr; }
  .preset-row { gap: 4px; }
  .preset-btn { padding: 5px 10px; font-size: 0.72rem; }
}