:root {
    --bg: #020617;
    --panel: rgba(15, 23, 42, 0.75);
    --border: rgba(255, 255, 255, 0.07);
    --primary: #22d3ee;
    --secondary: #a855f7;
    --text: #f8fafc;
    --muted: #64748b;
}

body.sim-page {
    font-family: 'Outfit', sans-serif;
    color: var(--text);
    margin: 0;
    padding: 0;
    overflow: hidden;
    background: #020617;
    touch-action: none;
    overscroll-behavior: none;
}

#phet-stage {
    position: absolute;
    top: 0;
    left: 0;
    width: 1280px;
    height: 720px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    background: var(--bg);
    transform-origin: top left;
}


.sim-nav {
    position: relative !important;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.55rem 1.5rem;
    background: rgba(15, 23, 42, 0.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    z-index: 200;
}

#sim-app {
    display: flex;
    flex: 1;
    width: 100%;
    overflow: hidden;
}

.sim-container {
    flex: 1;
    display: flex;
    width: 100%;
}

.canvas-panel {
    flex: 1;
    background: var(--bg);
    position: relative;
    overflow: hidden;
    touch-action: none;
}

#simCanvas {
    width: 100%;
    height: 100%;
    display: block;
    cursor: crosshair;
    touch-action: none;
}

.control-panel {
    width: 320px;
    background: var(--panel);
    backdrop-filter: blur(16px);
    border-left: 1px solid var(--border);
    padding: 1.25rem;
    overflow-y: auto;
    z-index: 10;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    touch-action: pan-y;
}

.phet-theme {
    font-family: inherit;
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.sim-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text);
}

.logo-icon {
    font-size: 1.6rem;
}

.logo-thin {
    font-weight: 300;
}

.nav-breadcrumbs {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 0.9rem;
    color: var(--muted);
}

.nav-breadcrumbs a {
    color: var(--muted);
    text-decoration: none;
    transition: color 0.2s;
}

.nav-breadcrumbs a:hover {
    color: var(--primary);
}

.nav-breadcrumbs .current {
    color: var(--primary);
    font-weight: 600;
}

.nav-breadcrumbs .sep {
    opacity: 0.4;
}

.nav-right {
    display: flex;
    gap: 1rem;
}

.nav-back {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.5rem 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border);
    border-radius: 12px;
    color: var(--text);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s;
}

.nav-back:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--primary);
    color: var(--primary);
}

.phet-box {
    background: var(--panel);
    border-radius: 12px;
    padding: 1.25rem;
    border: 1px solid var(--border);
    backdrop-filter: blur(10px);
}

.section-header {
    font-size: 0.82rem;
    margin: -1.25rem -1.25rem 1rem -1.25rem;
    color: white;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    font-weight: 700;
    padding: 10px 1.25rem;
    border-top-left-radius: 12px;
    border-top-right-radius: 12px;
    opacity: 0.9;
}

.control-group {
    margin-bottom: 10px;
}

label {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.9rem;
    color: #f8fafc;
    cursor: pointer;
    user-select: none;
}

.val-display {
    font-weight: 700;
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.1rem;
}

/* Base Slider styling */
input[type="range"] {
    width: 100%;
    height: 8px;
    border-radius: 8px;
    outline: none;
    -webkit-appearance: none;
    appearance: none;
    background: #334155;
    margin-top: 15px;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: white;
    cursor: grab;
    border: 3px solid #cbd5e1;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    transition: all 0.2s;
}

input[type="range"]::-webkit-slider-thumb:active {
    cursor: grabbing;
    transform: scale(1.1);
}

.slider-red::-webkit-slider-thumb {
    border-color: #ef4444 !important;
}

.slider-blue::-webkit-slider-thumb {
    border-color: #3b82f6 !important;
}

/* Custom Checkboxes */
.checkbox-group label {
    padding: 4px 0;
    transition: color 0.2s;
}

.checkbox-group label:hover {
    opacity: 0.8;
}

input[type="checkbox"] {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border: 2px solid #475569;
    border-radius: 4px;
    background: #0f172a;
    cursor: pointer;
    position: relative;
    transition: all 0.2s;
}

input[type="checkbox"]:checked {
    background: #3b82f6;
    border-color: #3b82f6;
}

input[type="checkbox"]:checked::after {
    content: "\2713";
    color: white;
    font-size: 14px;
    font-weight: bold;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -51%);
}

#grid-overlay {
    position: absolute;
    inset: 0;
    pointer-events: none;
    display: none;
    z-index: 5;
    opacity: 0.15;
    background-image: radial-gradient(#64748b 2px, transparent 2px);
    background-size: 40px 40px;
}

#distance-tag {
    position: absolute;
    display: none;
    background: rgba(15, 23, 42, 0.9);
    color: white;
    padding: 6px 14px;
    border-radius: 30px;
    font-size: 0.9rem;
    pointer-events: none;
    border: 1px solid rgba(255, 255, 255, 0.2);
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 500;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
    z-index: 20;
    transform: translate(-50%, -50%);
}

.equation-box {
    background: rgba(15, 23, 42, 0.85) !important;
    border: 1px solid rgba(255, 255, 255, 0.15) !important;
    box-shadow: 0 20px 40px rgba(0,0,0,0.3) !important;
    transition: transform 0.3s ease;
    backdrop-filter: blur(10px);
}

#voltage-sensor {
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
    border-radius: 50%;
    touch-action: none;
}