/* ═══════════════════════════════════════════════════════════════
   MATHVIS V2 — STYLE ADDITIONS
   Loaded after the base v1 stylesheet. Reuses all existing CSS
   variables (--accent, --glass-bg, --text-primary, etc.) so new
   components inherit the same dark-glass visual language.
   ═══════════════════════════════════════════════════════════════ */

/* ── New subject colors ───────────────────────────────────────── */
:root {
  --cat-arithmetic: #06B6D4;
  --cat-measurement: #84CC16;
  --cat-finance: #F59E0B;
}
.cat-Arithmetic  { --cat: var(--cat-arithmetic);  }
.cat-Measurement { --cat: var(--cat-measurement); }
.cat-Finance     { --cat: var(--cat-finance);     }
.filter-chip[data-cat="Arithmetic"].active { background: var(--cat-arithmetic); border-color: var(--cat-arithmetic); box-shadow: 0 4px 14px rgba(6,182,212,0.4); }
.filter-chip[data-cat="Measurement"].active { background: var(--cat-measurement); border-color: var(--cat-measurement); box-shadow: 0 4px 14px rgba(132,204,22,0.4); }
.filter-chip[data-cat="Finance"].active { background: var(--cat-finance); border-color: var(--cat-finance); box-shadow: 0 4px 14px rgba(245,158,11,0.4); }
.filter-chip[data-grade="Class 1-2"].active,
.filter-chip[data-grade="Class 3-5"].active { background: var(--green); border-color: var(--green); box-shadow: 0 4px 14px rgba(16,185,129,0.4); }

/* ── Visual tab mode toggle (Explore vs Solve) ───────────────────── */
.vis-mode-toggle { display: flex; gap: 6px; padding: 4px; background: var(--glass-bg); border: 1px solid var(--glass-border); border-radius: 12px; margin: 0 16px 12px; }
.vis-mode-btn { flex: 1; padding: 9px 0; border: none; background: transparent; color: var(--text-secondary); font-family: var(--font-body); font-weight: 600; font-size: 0.8125rem; border-radius: 9px; cursor: pointer; transition: all 0.2s; }
.vis-mode-btn.active { background: var(--accent); color: #fff; box-shadow: 0 2px 10px var(--accent-glow); }

.solve-panel { padding: 0 16px 16px; }
.solve-given-fields { display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: 10px; margin-bottom: 14px; }
.solve-field label { display: block; font-size: 0.75rem; color: var(--text-secondary); margin-bottom: 4px; font-weight: 600; }
.solve-field input { width: 100%; padding: 10px 12px; border-radius: 10px; border: 1px solid var(--glass-border); background: var(--glass-bg); color: var(--text-primary); font-family: var(--font-mono); font-size: 0.9375rem; }
.solve-field input:focus { outline: none; border-color: var(--accent); }
.solve-which-row { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 14px; }
.solve-which-chip { padding: 7px 14px; border-radius: 20px; border: 1px solid var(--glass-border); background: var(--glass-bg); color: var(--text-secondary); font-size: 0.8125rem; font-weight: 600; cursor: pointer; transition: all 0.2s; }
.solve-which-chip.active { background: var(--accent); border-color: var(--accent); color: #fff; }
.solve-btn-main { width: 100%; padding: 13px; border-radius: 12px; border: none; background: linear-gradient(135deg, var(--accent), #5B21B6); color: #fff; font-weight: 700; font-size: 0.9375rem; cursor: pointer; box-shadow: 0 4px 16px var(--accent-glow); }
.solve-btn-main:disabled { opacity: 0.5; cursor: not-allowed; }
.solve-error { margin-top: 12px; padding: 12px 14px; border-radius: 10px; background: rgba(239,68,68,0.1); border: 1px solid rgba(239,68,68,0.3); color: var(--red-light); font-size: 0.875rem; }
.solve-result-wrap { margin-top: 16px; }
.solve-result-banner { padding: 12px 14px; border-radius: 10px; background: rgba(16,185,129,0.1); border: 1px solid rgba(16,185,129,0.3); color: var(--green-light); font-weight: 700; font-size: 0.9375rem; margin-bottom: 12px; }

/* ── Step Player ──────────────────────────────────────────────── */
.step-player-title { font-size: 0.8125rem; font-weight: 700; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 10px; }
.step-player-dots { display: flex; gap: 6px; justify-content: center; margin-bottom: 14px; }
.step-dot { width: 9px; height: 9px; border-radius: 50%; border: none; background: var(--glass-border); cursor: pointer; padding: 0; transition: all 0.2s; }
.step-dot.current { background: var(--accent); width: 22px; border-radius: 5px; }
.step-dot.done { background: var(--accent-light); }
.step-player-card { background: var(--glass-bg); border: 1px solid var(--glass-border); border-radius: 14px; padding: 16px; min-height: 84px; transition: opacity 0.14s; }
.step-player-card.step-fade-out { opacity: 0; }
.step-player-label { font-size: 0.75rem; font-weight: 700; color: var(--accent-light); text-transform: uppercase; letter-spacing: 0.04em; margin-bottom: 8px; }
.step-player-expr { font-family: var(--font-mono); font-size: 1.0625rem; color: var(--text-primary); margin-bottom: 6px; word-break: break-word; }
.step-player-note { font-size: 0.8125rem; color: var(--text-secondary); }
.step-player-controls { display: flex; align-items: center; gap: 8px; margin-top: 14px; flex-wrap: wrap; }
.step-btn { padding: 8px 12px; border-radius: 9px; border: 1px solid var(--glass-border); background: var(--glass-bg); color: var(--text-primary); cursor: pointer; font-size: 0.875rem; transition: all 0.2s; }
.step-btn:hover { border-color: var(--glass-border-hover); background: var(--glass-bg-hover); }
.step-btn-play { background: var(--accent); border-color: var(--accent); color: #fff; min-width: 42px; }
.step-speed-group { display: flex; gap: 4px; margin-left: auto; }
.step-speed-btn { padding: 6px 9px; border-radius: 7px; border: 1px solid var(--glass-border); background: transparent; color: var(--text-dim); font-size: 0.75rem; cursor: pointer; }
.step-speed-btn.active { color: var(--accent-light); border-color: var(--accent-light); }

/* ── Activities (Play & Learn) ────────────────────────────────── */
.activity-note { font-size: 0.875rem; color: var(--text-secondary); margin-bottom: 12px; padding: 10px 12px; background: rgba(124,58,237,0.08); border-radius: 10px; border: 1px solid rgba(124,58,237,0.15); }
.activity-canvas-wrap { border-radius: 14px; overflow: hidden; border: 1px solid var(--glass-border); margin-bottom: 14px; background: #06060F; }
.activity-canvas { width: 100%; height: 260px; display: block; }
.activity-sliders { display: flex; flex-direction: column; gap: 10px; }
.activity-stepper-row, .taptobuild-row { display: flex; flex-wrap: wrap; gap: 16px; justify-content: center; margin-top: 8px; }
.stepper-group { display: flex; flex-direction: column; align-items: center; gap: 6px; }
.stepper-label { font-size: 0.8125rem; font-weight: 700; color: var(--text-secondary); }
.stepper-controls { display: flex; align-items: center; gap: 10px; }
.stepper-btn { width: 36px; height: 36px; border-radius: 10px; border: 1px solid var(--glass-border); background: var(--glass-bg); color: var(--text-primary); font-size: 1.1rem; font-weight: 700; cursor: pointer; }
.stepper-btn:hover { background: var(--accent); border-color: var(--accent); color: #fff; }
.stepper-btn-big { width: 52px; height: 52px; font-size: 1.5rem; border-radius: 14px; }
.stepper-val { min-width: 36px; text-align: center; font-family: var(--font-mono); font-weight: 700; font-size: 1.0625rem; }

.fillblank-steps { display: flex; flex-direction: column; gap: 10px; }
.fillblank-step { padding: 12px 14px; border-radius: 12px; background: var(--glass-bg); border: 1px solid var(--glass-border); }
.fillblank-step.is-blank { border-color: rgba(245,158,11,0.35); background: rgba(245,158,11,0.06); }
.fillblank-step-label { display: block; font-size: 0.75rem; font-weight: 700; color: var(--text-secondary); margin-bottom: 6px; text-transform: uppercase; letter-spacing: 0.03em; }
.fillblank-step-expr { font-family: var(--font-mono); font-size: 1rem; color: var(--text-primary); }
.fillblank-input { width: 64px; padding: 5px 8px; margin: 0 2px; border-radius: 7px; border: 1.5px solid var(--glass-border-hover); background: var(--bg-elevated); color: var(--text-primary); font-family: var(--font-mono); font-size: 0.9375rem; text-align: center; }
.fillblank-input.correct { border-color: var(--green); background: rgba(16,185,129,0.12); color: var(--green-light); }
.fillblank-input.incorrect { border-color: var(--red); background: rgba(239,68,68,0.12); color: var(--red-light); }
.fillblank-actions { display: flex; align-items: center; gap: 12px; margin-top: 14px; }
.fillblank-result { font-size: 0.875rem; font-weight: 700; color: var(--text-secondary); }
.fillblank-result.all-correct { color: var(--green-light); }

.dragmatch-board { display: flex; gap: 20px; flex-wrap: wrap; }
.dragmatch-chips { display: flex; flex-direction: column; gap: 10px; min-width: 140px; }
.dragmatch-chip { padding: 10px 14px; border-radius: 10px; background: var(--accent); color: #fff; font-weight: 600; font-size: 0.875rem; cursor: grab; touch-action: none; user-select: none; box-shadow: 0 3px 10px rgba(124,58,237,0.3); }
.dragmatch-chip.dragging { cursor: grabbing; box-shadow: 0 8px 24px rgba(0,0,0,0.4); }
.dragmatch-chip.chip-correct { background: var(--green); cursor: default; box-shadow: 0 3px 10px rgba(16,185,129,0.3); }
.dragmatch-chip.chip-incorrect { background: var(--red); }
.dragmatch-slots { display: flex; flex-direction: column; gap: 10px; flex: 1; min-width: 140px; }
.dragmatch-slot { display: flex; align-items: center; gap: 10px; }
.dragmatch-slot-label { font-family: var(--font-mono); font-weight: 700; color: var(--text-secondary); min-width: 28px; }
.dragmatch-slot-drop { flex: 1; min-height: 44px; border: 2px dashed var(--glass-border); border-radius: 10px; display: flex; align-items: center; padding: 4px; }
.dragmatch-result { margin-top: 14px; }

/* ── Scanner modal ────────────────────────────────────────────── */
#scanner-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.7); backdrop-filter: blur(8px); z-index: 200; display: none; align-items: center; justify-content: center; padding: 16px; }
#scanner-overlay.open { display: flex; }
#scanner-modal { width: 100%; max-width: 480px; background: var(--bg-elevated); border-radius: 20px; border: 1px solid var(--glass-border); padding: 22px; max-height: 90vh; overflow-y: auto; }
.scanner-title { font-family: var(--font-display); font-weight: 800; font-size: 1.25rem; margin-bottom: 6px; }
.scanner-sub { font-size: 0.875rem; color: var(--text-secondary); margin-bottom: 16px; }
.scanner-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-bottom: 14px; }
.scanner-action-btn { padding: 16px 10px; border-radius: 14px; border: 1px solid var(--glass-border); background: var(--glass-bg); color: var(--text-primary); font-weight: 700; font-size: 0.875rem; cursor: pointer; display: flex; flex-direction: column; align-items: center; gap: 6px; }
.scanner-action-btn:hover { border-color: var(--accent); background: rgba(124,58,237,0.08); }
.scanner-action-icon { font-size: 1.5rem; }
.scanner-preview { width: 100%; border-radius: 12px; margin-bottom: 12px; max-height: 220px; object-fit: contain; background: #000; }
.scanner-progress { font-size: 0.8125rem; color: var(--accent-light); margin-bottom: 10px; }
.scanner-extracted-label { font-size: 0.75rem; font-weight: 700; color: var(--text-secondary); margin-bottom: 6px; }
.scanner-extracted-text { width: 100%; min-height: 70px; padding: 10px 12px; border-radius: 10px; border: 1px solid var(--glass-border); background: var(--glass-bg); color: var(--text-primary); font-family: var(--font-mono); font-size: 0.9375rem; margin-bottom: 12px; }
.scanner-close-btn { width: 100%; padding: 10px; border-radius: 10px; border: 1px solid var(--glass-border); background: transparent; color: var(--text-secondary); cursor: pointer; margin-top: 6px; }

/* ── Solver page: mode switch + AI quota ──────────────────────── */
.solver-mode-toggle { display: flex; gap: 8px; max-width: 420px; margin: 0 auto 20px; padding: 4px; background: var(--glass-bg); border: 1px solid var(--glass-border); border-radius: 14px; }
.solver-mode-btn { flex: 1; padding: 11px 0; border: none; background: transparent; color: var(--text-secondary); font-weight: 700; font-size: 0.875rem; border-radius: 10px; cursor: pointer; }
.solver-mode-btn.active { background: var(--accent); color: #fff; box-shadow: 0 2px 12px var(--accent-glow); }
.scan-trigger-row { display: flex; gap: 10px; margin-bottom: 14px; }
.scan-trigger-btn { flex: 1; padding: 13px; border-radius: 12px; border: 1px solid var(--glass-border); background: var(--glass-bg); color: var(--text-primary); font-weight: 700; font-size: 0.875rem; cursor: pointer; display: flex; align-items: center; justify-content: center; gap: 8px; }
.scan-trigger-btn:hover { border-color: var(--accent); }
.ai-quota-pill { display: inline-flex; align-items: center; gap: 6px; padding: 6px 12px; border-radius: 20px; background: rgba(124,58,237,0.1); border: 1px solid rgba(124,58,237,0.25); color: var(--accent-light); font-size: 0.8125rem; font-weight: 600; margin-bottom: 14px; }
.formula-picker-search { width: 100%; padding: 12px 14px; border-radius: 12px; border: 1px solid var(--glass-border); background: var(--glass-bg); color: var(--text-primary); font-size: 0.9375rem; margin-bottom: 14px; }
.formula-picker-list { display: flex; flex-direction: column; gap: 8px; max-height: 320px; overflow-y: auto; margin-bottom: 16px; }
.formula-picker-item { padding: 12px 14px; border-radius: 10px; background: var(--glass-bg); border: 1px solid var(--glass-border); cursor: pointer; display: flex; justify-content: space-between; align-items: center; }
.formula-picker-item:hover { border-color: var(--accent); }
.formula-picker-item.selected { border-color: var(--accent); background: rgba(124,58,237,0.1); }

/* ── Foundation-tier (Class 1-2 / 3-5) cards get slightly rounder corners for a softer, kid-friendly feel ── */
.formula-card.cat-Arithmetic, .formula-card.cat-Measurement { border-radius: 22px; }

@media (max-width: 640px) {
  .dragmatch-board { flex-direction: column; }
  .scanner-actions { grid-template-columns: 1fr; }
}