/* =====================================================================
   QUADRILATERALS (CLASS 9) — Maths Notes
   Figure wrappers, SVG styles, animated diagrams, proof boxes, tables and cards.
   Base styles (.notes-page-wrap, .notes-toc, .topic-section, .concept-card,
   .formula-box, .definition-box, .props-list) come from /css/notes-content.css.
   ===================================================================== */

.qd-fig { display: flex; flex-direction: column; align-items: center; margin: 22px auto; max-width: 500px; }
.qd-fig svg { display: block; width: 100%; height: auto; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; user-select: none; }
.qd-caption { margin-top: 8px; font-size: 13px; color: #64748b; text-align: center; line-height: 1.5; }

.proof-box { background: #f8fafc; border: 1px solid #e2e8f0; border-left: 4px solid #2563eb; border-radius: 6px; padding: 16px 20px; margin: 18px 0; font-size: 14.5px; line-height: 1.7; color: #334155; }
.proof-header { font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; color: #2563eb; margin-bottom: 8px; }
.proof-step { margin-bottom: 8px; }
.proof-step strong { color: #0f172a; }

.qd-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 16px; margin: 20px 0; }
.qd-card { background: #fff; border: 1px solid #e2e8f0; border-radius: 8px; padding: 18px 20px; box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04); }
.qd-card h4 { margin: 0 0 8px; font-size: 15.5px; font-weight: 700; color: #0f172a; }
.qd-card p { margin: 0 0 10px; font-size: 13.5px; color: #475569; line-height: 1.55; }
.qd-badge { display: inline-block; font-size: 11.5px; font-weight: 700; text-transform: uppercase; color: #2563eb; background: #eff6ff; border: 1px solid #bfdbfe; border-radius: 4px; padding: 2px 7px; margin-bottom: 8px; }

.qd-table-wrap { overflow-x: auto; margin: 16px 0; }
.qd-table { width: 100%; border-collapse: collapse; font-size: 13.5px; line-height: 1.55; color: #334155; }
.qd-table th, .qd-table td { border: 1px solid #e2e8f0; padding: 8px 10px; text-align: left; vertical-align: top; }
.qd-table th { background: #f1f5f9; color: #0f172a; font-weight: 700; }

.qd-svg-axis { stroke: #0f172a; stroke-width: 1.8; }
.qd-svg-line { fill: none; stroke: #2563eb; stroke-width: 2.2; }
.qd-svg-dash { fill: none; stroke: #94a3b8; stroke-width: 1.3; stroke-dasharray: 4; }
.qd-svg-dot { fill: #2563eb; stroke: #fff; stroke-width: 1.5; }
.qd-svg-dot-r { fill: #dc2626; stroke: #fff; stroke-width: 1.5; }
.qd-svg-t { font-size: 12.5px; font-weight: 600; fill: #1e293b; }
.qd-svg-tb { font-size: 12.5px; font-weight: 700; fill: #2563eb; }
.qd-svg-tr { font-size: 12.5px; font-weight: 700; fill: #dc2626; }
.qd-svg-tg { font-size: 12.5px; font-weight: 700; fill: #16a34a; }
.qd-svg-tm { font-size: 11.5px; font-weight: 500; fill: #64748b; }

/* ---------- Animated diagrams ---------- */

/* Hinged grid: squares lean into parallelograms while the bottom stick stays fixed */
.qd-hinge { transform-origin: 120px 170px; animation: qdHinge 7s ease-in-out infinite; }
@keyframes qdHinge { 0%, 12% { transform: skewX(0deg); } 45%, 65% { transform: skewX(-28deg); } 100% { transform: skewX(0deg); } }

/* Construction lines draw themselves in */
.qd-draw { stroke-dasharray: var(--len); stroke-dashoffset: var(--len); animation: qdDraw 6s ease-in-out infinite; animation-delay: var(--d, 0s); }
@keyframes qdDraw { 0%, 8% { stroke-dashoffset: var(--len); } 35%, 88% { stroke-dashoffset: 0; } 100% { stroke-dashoffset: var(--len); } }

/* Highlighted shape pulses gently */
.qd-pulse { animation: qdPulse 3s ease-in-out infinite; }
@keyframes qdPulse { 0%, 100% { opacity: 0.3; } 50% { opacity: 1; } }

/* Tiling: a copy turns 180 degrees about the midpoint of a side */
.qd-turn { transform-origin: 160px 90px; animation: qdTurn 6s ease-in-out infinite; }
@keyframes qdTurn { 0%, 15% { transform: rotate(0deg); } 55%, 85% { transform: rotate(180deg); } 100% { transform: rotate(0deg); } }

@media (prefers-reduced-motion: reduce) {
  .qd-hinge, .qd-draw, .qd-pulse, .qd-turn { animation: none !important; }
  .qd-hinge { transform: skewX(-20deg); }
  .qd-draw { stroke-dashoffset: 0; }
  .qd-turn { transform: rotate(180deg); }
}