/* ── Welding Symbol Trainer ─────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:        #0d1117;
  --surface:   #161b27;
  --surface2:  #1f2535;
  --border:    #2a3050;
  --accent:    #e91e63;
  --accent-lo: rgba(233,30,99,.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;
  /* Weld-specific colours */
  --ref-line:  #4fc3f7;
  --plate:     #546e7a;
  --weld-fill: #ef6c00;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  min-height: 100vh;
  padding: 0 16px;
}
#app { max-width: 1060px; margin: 0 auto; display: flex; flex-direction: column; gap: 14px; }

/* ── Header ────────────────────────────────────────────────────── */
header { text-align: center; padding: 4px 0; }
header h1 {
  font-size: 1.8rem; font-weight: 700;
  background: linear-gradient(120deg, #e91e63 0%, #f48fb1 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 ──────────────────────────────────────────────── */
.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: 5px 13px; 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); }

.std-badge {
  font-size: 0.78rem; font-weight: 700; color: var(--accent);
  background: var(--accent-lo); border: 1px solid rgba(233,30,99,.3);
  border-radius: 6px; padding: 3px 10px;
}

/* ── Canvas card ───────────────────────────────────────────────── */
.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; }

/* ── Buttons (shared) ──────────────────────────────────────────── */
.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); }

/* ── Weld Selector Panel (Explore mode) ────────────────────────── */
.weld-selector {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 14px 16px;
}
.ws-header {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  margin-bottom: 12px;
}
.ws-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(155px, 1fr));
  gap: 8px;
}
.ws-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, transform .12s;
}
.ws-btn:hover { border-color: rgba(233,30,99,.45); color: var(--text); background: rgba(233,30,99,.06); }
.ws-btn.active {
  border-color: var(--accent); color: #fff; background: rgba(233,30,99,.15);
  box-shadow: 0 0 14px var(--accent-lo);
}
.ws-btn:active { transform: scale(0.97); }
.ws-btn-name { display: block; font-size: 0.82rem; font-weight: 700; }
.ws-btn-id   { display: block; font-size: 0.62rem; color: var(--text-dim); margin-top: 2px; }

/* ── Placement Toggle ──────────────────────────────────────────── */
.placement-row {
  display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
}

/* ── Weld Info Card ────────────────────────────────────────────── */
.weld-info {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 16px 18px; display: flex; flex-direction: column; gap: 8px;
}
.wi-top { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.wi-name { font-size: 1.15rem; font-weight: 800; color: var(--text); }
.wi-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);
}
.wi-desc { font-size: 0.85rem; color: var(--text-dim); line-height: 1.65; }
.wi-apps-label {
  font-size: 0.68rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: .08em; color: var(--accent); margin-top: 4px;
}
.wi-apps { font-size: 0.82rem; color: var(--text-dim); line-height: 1.55; }

/* ── Learn Mode Info ───────────────────────────────────────────── */
.learn-info {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 16px 18px;
}
.learn-info h3 {
  font-size: 0.9rem; font-weight: 700; color: var(--accent); margin-bottom: 8px;
}
.learn-parts {
  display: grid; grid-template-columns: 1fr 1fr; gap: 8px;
}
.learn-part {
  display: flex; align-items: flex-start; gap: 8px;
  padding: 8px 10px; border-radius: 8px;
  background: var(--surface2); border: 1px solid var(--border);
  cursor: pointer; transition: border-color .18s, background .18s;
}
.learn-part:hover { border-color: rgba(233,30,99,.4); }
.learn-part.active { border-color: var(--accent); background: rgba(233,30,99,.08); }
.learn-dot {
  width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; margin-top: 3px;
}
.learn-part-name { font-size: 0.78rem; font-weight: 700; color: var(--text); }
.learn-part-desc { font-size: 0.68rem; color: var(--text-dim); line-height: 1.5; margin-top: 2px; }

/* ── Answer grid (Practice / Quiz) ─────────────────────────────── */
.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;
}
.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(233,30,99,.06); }
.answer-btn:active:not(.locked) { transform: scale(0.97); }
.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; }

.qp-bottom {
  display: flex; align-items: center; gap: 12px; flex-wrap: wrap; margin-top: 14px;
}
.feedback { font-size: 0.88rem; font-weight: 600; min-width: 0; }
.feedback.ok  { color: var(--green); }
.feedback.err { color: var(--red); }

/* ── Practice bar (score row) ──────────────────────────────────── */
.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; }

/* ── Quiz bar ──────────────────────────────────────────────────── */
.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); }
.qbar-hint    { font-size: 0.78rem; 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 panel ─────────────────────────────────────────── */
.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 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-correct, .qr-given { font-size: 0.78rem; color: var(--text-dim); }
.qr-correct strong, .qr-given strong { color: var(--text); font-family: var(--mono); }
.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); }

/* ── Responsive ────────────────────────────────────────────────── */
@media (max-width: 768px) {
  .learn-parts { grid-template-columns: 1fr; }
  .answer-grid { grid-template-columns: 1fr 1fr; }
  .ws-grid { grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); }
  .controls-bar { gap: 10px; }
}
@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; }
  .ws-grid { grid-template-columns: 1fr 1fr; }
  .learn-parts { grid-template-columns: 1fr; }
  .qr-row { grid-template-columns: 24px 1fr 26px; }
  .qr-given { display: none; }
}