/* Physics Solver */
.py-form { display: flex; flex-direction: column; gap: 18px; }
.py-label { display: block; font-size: 14px; font-weight: 700; margin-bottom: 6px; color: #1e293b; }
.py-sym { font-weight: 600; color: #64748b; }
.py-select, .py-input, .py-unit { padding: 10px 12px; border: 1px solid #cbd5e1; border-radius: 12px; background: #fff; color: #0f172a; font-size: 15px; min-height: 46px; max-width: 100%; }
.py-select { width: 100%; }
.py-eq-line { margin: 8px 0 0; font-size: 14px; color: #475569; }
.py-eq { display: inline-block; padding: 2px 10px; border-radius: 8px; background: #eef2ff; color: #3730a3; font-weight: 700; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; overflow-wrap: anywhere; }
.py-vars { display: flex; flex-direction: column; gap: 12px; }
.py-row { padding: 10px 12px; border: 1px solid #e2e8f0; border-radius: 14px; background: #f8fafc; }
.py-row .py-label { margin-bottom: 8px; font-size: 13px; }
.py-unknown { border-color: #a5b4fc; background: #eef2ff; }
.py-tag { display: inline-block; margin-left: 4px; padding: 1px 8px; border-radius: 999px; background: #4f46e5; color: #fff; font-size: 11px; font-weight: 700; }
.py-fields { display: flex; gap: 8px; align-items: center; }
.py-input { flex: 1 1 auto; min-width: 0; }
.py-input:disabled { background: #e2e8f0; cursor: not-allowed; }
.py-unit { flex: 0 0 auto; width: 40%; max-width: 160px; }
.py-nounit { flex: 0 0 auto; font-size: 13px; color: #64748b; width: 40%; max-width: 160px; text-align: center; }
.py-opts { display: grid; grid-template-columns: minmax(0, 1fr); gap: 12px; }
@media (min-width: 560px) { .py-opts { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.py-actions { display: flex; flex-wrap: wrap; gap: 8px; }
.py-btn { flex: 1 1 200px; padding: 13px 18px; border-radius: 12px; background: #4f46e5; color: #fff; font-weight: 700; border: 0; cursor: pointer; min-height: 48px; font-size: 16px; }
.py-btn:hover { background: #4338ca; }
.py-btn2 { padding: 12px 18px; border-radius: 12px; background: #f1f5f9; color: #334155; font-weight: 600; border: 1px solid #e2e8f0; cursor: pointer; min-height: 46px; }
.py-btn2:hover { background: #e2e8f0; }
.py-result { padding: 14px; border: 1px solid #e2e8f0; border-radius: 14px; background: #fff; min-height: 64px; }
.py-empty { margin: 0; font-size: 14px; color: #64748b; }
.py-error { margin: 0; padding: 10px 12px; border-radius: 10px; background: #fff1f2; color: #9f1239; font-size: 14px; font-weight: 600; overflow-wrap: anywhere; }
.py-answer { margin: 0 0 6px; font-size: 20px; color: #0f172a; overflow-wrap: anywhere; }
.py-answer strong { color: #4338ca; }
.py-invalid { font-size: 15px; color: #64748b; text-decoration: line-through; }
.py-note { display: inline-block; font-size: 12px; font-weight: 600; color: #64748b; text-decoration: none; }
.py-work-title { margin: 14px 0 6px; font-size: 13px; font-weight: 700; color: #475569; }
.py-work { margin: 0; padding: 10px 12px; border-radius: 10px; background: #f1f5f9; color: #1e293b; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 13px; line-height: 1.6; white-space: pre-wrap; overflow-wrap: anywhere; }
.py-ai { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 10px; padding-top: 4px; border-top: 1px dashed #cbd5e1; }
.py-ai-btn { padding: 11px 16px; border-radius: 12px; border: 1px dashed #94a3b8; background: #f1f5f9; color: #64748b; font-weight: 600; min-height: 44px; cursor: not-allowed; }
.py-badge { padding: 2px 10px; border-radius: 999px; background: #fef3c7; color: #92400e; font-size: 11px; font-weight: 700; }
.py-ai-help { flex-basis: 100%; margin: 0; font-size: 12px; color: #64748b; }
.py-list { margin: 0; padding-left: 18px; font-size: 14px; line-height: 1.7; list-style: disc; }
.dark .py-label, .dark .py-answer { color: #e2e8f0; }
.dark .py-sym, .dark .py-eq-line, .dark .py-empty, .dark .py-nounit, .dark .py-note, .dark .py-ai-help, .dark .py-work-title { color: #94a3b8; }
.dark .py-select, .dark .py-input, .dark .py-unit { background: #334155; border-color: #475569; color: #f1f5f9; }
.dark .py-input:disabled { background: #1e293b; }
.dark .py-eq { background: #1e1b4b; color: #c7d2fe; }
.dark .py-row { background: #0f172a; border-color: #334155; }
.dark .py-unknown { background: #1e1b4b; border-color: #4338ca; }
.dark .py-btn2 { background: #334155; border-color: #475569; color: #e2e8f0; }
.dark .py-btn2:hover { background: #475569; }
.dark .py-result { background: #0f172a; border-color: #334155; }
.dark .py-error { background: #4c0519; color: #fecdd3; }
.dark .py-answer strong { color: #a5b4fc; }
.dark .py-invalid { color: #94a3b8; }
.dark .py-work { background: #1e293b; color: #e2e8f0; }
.dark .py-ai { border-color: #475569; }
.dark .py-ai-btn { background: #1e293b; border-color: #475569; color: #94a3b8; }
.dark .py-badge { background: #78350f; color: #fde68a; }