:root { 
    --billy-orange: #F5A623; 
    --billy-blue: #008080; 
    --bg-light: #f9f9f9; 
    --slate-200: #e2e8f0;
    --slate-500: #64748b;
    --slate-800: #1e293b;
    --cyan-glow: #6ee7ff;
    --green-glow: #34d399;
}

#billy-notes-wrapper {
    line-height: 1.6; color: #333; width: 100%; max-width: 800px;
    margin: 0 auto; background: #fff;
    font-family: 'Segoe UI', 'Microsoft JhengHei', sans-serif;
    -webkit-font-smoothing: antialiased;
}

#billy-notes-wrapper h1 { 
    color: var(--billy-blue); border-bottom: 3px solid var(--billy-orange); 
    padding-bottom: 10px; font-size: 2em; text-align: center; 
    margin-bottom: 20px; margin-top: 0; 
}
.zh-text { color: #666; font-size: 0.9em; display: block; margin-top: 4px; font-weight: normal; }

.note-card { 
    background: var(--bg-light); border-radius: 12px; padding: 0; 
    margin: 20px 0; box-shadow: 0 4px 15px rgba(0,0,0,0.05); 
    border-top: 4px solid var(--billy-blue); overflow: hidden;
}

.card-header {
    padding: 20px 25px; border-bottom: 1px solid var(--slate-200);
    display: flex; flex-direction: column; justify-content: center;
    align-items: center; background: #fff; gap: 15px;
}

.hud-display {
    text-align: center; width: 100%; padding: 15px; background: var(--bg-light);
    border-radius: 8px; border: 1px solid var(--slate-200); position: relative;
    overflow: hidden; display: grid; grid-template-columns: 1fr 1fr; gap: 10px;
}
.hud-display::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 4px;
    background: linear-gradient(90deg, var(--billy-blue), var(--billy-orange));
}
.hud-val { font-size: 1.75rem; font-family: monospace; font-weight: bold; color: var(--slate-800); line-height: 1.1; }

.diagram-container {
    position: relative; width: 100%; background: radial-gradient(circle at 50% 50%, #13264b 0%, #0b1220 60%, #070b14 100%);
    border-bottom: 1px solid var(--slate-200); padding: 0; line-height: 0;
    aspect-ratio: 16/10; overflow: hidden; touch-action: none;
}
canvas { display: block; width: 100%; height: 100%; touch-action: none; }

.sliders-wrapper {
    padding: 25px; background: #fff; border-bottom: 1px solid var(--slate-200);
    display: grid; grid-template-columns: 1fr 1fr; gap: 20px;
}
@media (max-width: 600px) { .sliders-wrapper { grid-template-columns: 1fr; } }
.slider-group { display: flex; flex-direction: column; gap: 8px; }
.slider-header { display: flex; justify-content: space-between; align-items: center; font-weight: bold; font-size: 0.9rem; color: var(--slate-800); }
.val-badge { background: var(--bg-light); border: 1px solid var(--slate-200); padding: 2px 6px; border-radius: 4px; font-family: monospace; font-size: 0.85rem; color: var(--billy-blue); }

input[type=range] { -webkit-appearance: none; width: 100%; background: transparent; }
input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none; height: 18px; width: 18px; border-radius: 50%;
    background: var(--billy-blue); cursor: pointer; margin-top: -6px; 
    box-shadow: 0 2px 4px rgba(0,0,0,0.2); border: 2px solid white;
}
input[type=range]::-webkit-slider-runnable-track {
    width: 100%; height: 6px; cursor: pointer; background: var(--slate-200); border-radius: 3px;
}

.controls { padding: 25px; display: flex; flex-direction: column; gap: 15px; background: #fff; }
.btn-group { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; }
button {
    padding: 8px 16px; border-radius: 8px; font-weight: bold; font-size: 0.9rem;
    cursor: pointer; transition: all 0.2s; border: 2px solid transparent;
    display: flex; align-items: center; justify-content: center; gap: 6px;
}
button:active { transform: translateY(1px); }

.btn-primary { background: #e0f2f1; color: var(--billy-blue); border-color: #b2dfdb; }
.btn-primary.active { background: var(--billy-blue); color: white; border-color: var(--billy-blue); }

.btn-toggle { background: var(--bg-light); color: var(--slate-500); border-color: var(--slate-200); }
.btn-toggle.active { background: #eff6ff; color: #3b82f6; border-color: #bfdbfe; }

.btn-danger { background: #fef2f2; color: #ef4444; border-color: #fecaca; }
.btn-danger:hover { background: #fee2e2; }

.no-select { user-select: none; -webkit-user-select: none; }