/* ============================================
   Quantum Mechanical Atomic Model — Styles
   ============================================ */

:root {
    --bg-primary: #0a0e1a;
    --bg-secondary: #111827;
    --bg-panel: rgba(17, 24, 39, 0.92);
    --bg-card: rgba(30, 41, 59, 0.7);
    --border-color: rgba(99, 102, 241, 0.25);
    --border-glow: rgba(99, 102, 241, 0.5);
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --accent-1: #6366f1;
    --accent-2: #8b5cf6;
    --accent-3: #ec4899;
    --accent-gradient: linear-gradient(135deg, #6366f1, #8b5cf6, #ec4899);
    --shadow-lg: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.15);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-display: 'Orbitron', monospace;

    /* Orbital type colors */
    --color-s: #60a5fa;
    --color-p: #34d399;
    --color-d: #fbbf24;
    --color-f: #f87171;
}

*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html,
body {
    width: 100%;
    height: 100%;
    overflow: hidden;
    font-family: var(--font-main);
    background: var(--bg-primary);
    color: var(--text-primary);
}

#app {
    width: 100%;
    height: 100%;
    position: relative;
}

/* Canvas */
#canvas-container {
    position: absolute;
    inset: 0;
    z-index: 1;
}

#canvas-container canvas {
    display: block;
    width: 100%;
    height: 100%;
}

/* Header */
#header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 28px;
    background: linear-gradient(180deg, rgba(10, 14, 26, 0.95) 0%, rgba(10, 14, 26, 0) 100%);
    pointer-events: none;
}

#header>* {
    pointer-events: auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.back-to-table {
    display: inline-flex;
    align-items: center;
    padding: 6px 14px;
    border-radius: 20px;
    background: rgba(99, 102, 241, 0.12);
    border: 1px solid rgba(99, 102, 241, 0.25);
    color: var(--accent-1);
    text-decoration: none;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.5px;
    transition: all 0.3s ease;
    pointer-events: auto;
}

.back-to-table:hover {
    background: rgba(99, 102, 241, 0.25);
    border-color: var(--accent-1);
    box-shadow: 0 0 15px rgba(99, 102, 241, 0.3);
    transform: translateX(-2px);
}

.logo-icon {
    font-size: 28px;
    filter: drop-shadow(0 0 10px rgba(99, 102, 241, 0.6));
    animation: pulse-glow 2s ease-in-out infinite;
}

@keyframes pulse-glow {

    0%,
    100% {
        filter: drop-shadow(0 0 8px rgba(99, 102, 241, 0.4));
    }

    50% {
        filter: drop-shadow(0 0 20px rgba(99, 102, 241, 0.9));
    }
}

.logo h1 {
    font-family: var(--font-display);
    font-size: 17px;
    font-weight: 600;
    letter-spacing: 2px;
    text-transform: uppercase;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.element-display {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 20px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(16px);
}

.element-symbol {
    font-family: var(--font-display);
    font-size: 24px;
    font-weight: 700;
    color: var(--accent-1);
    text-shadow: 0 0 12px rgba(99, 102, 241, 0.5);
}

.element-name {
    font-size: 14px;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Electron Configuration Banner */
.config-banner {
    position: fixed;
    top: 60px;
    left: 28px;
    z-index: 100;
    padding: 10px 20px;
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    backdrop-filter: blur(16px);
    display: flex;
    align-items: center;
    gap: 10px;
    animation: fade-in 0.5s ease 0.3s both;
}

@keyframes fade-in {
    from {
        opacity: 0;
        transform: translateY(-8px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.config-label {
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
}

.config-text {
    font-family: var(--font-display);
    font-size: 14px;
    font-weight: 400;
    letter-spacing: 1.5px;
    background: linear-gradient(90deg, var(--color-s), var(--color-p), var(--color-d));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Control Panel */
#control-panel {
    position: fixed;
    top: 70px;
    right: 16px;
    bottom: 16px;
    width: 310px;
    z-index: 100;
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(20px);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    display: flex;
    flex-direction: column;
    transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.3s ease;
    overflow: hidden;
}

#control-panel.collapsed {
    transform: translateX(calc(100% + 20px));
    opacity: 0;
}

.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-color);
    flex-shrink: 0;
}

.panel-header h2 {
    font-family: var(--font-display);
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--text-secondary);
}

.panel-toggle-btn {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.panel-toggle-btn:hover {
    background: var(--bg-card);
    border-color: var(--accent-1);
    color: var(--text-primary);
}

.panel-content {
    flex: 1;
    overflow-y: auto;
    padding: 12px 20px 20px;
    scrollbar-width: thin;
    scrollbar-color: rgba(99, 102, 241, 0.3) transparent;
}

.panel-content::-webkit-scrollbar {
    width: 5px;
}

.panel-content::-webkit-scrollbar-track {
    background: transparent;
}

.panel-content::-webkit-scrollbar-thumb {
    background: rgba(99, 102, 241, 0.3);
    border-radius: 10px;
}

/* Control Groups */
.control-group {
    margin-bottom: 20px;
}

.control-label {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.control-value {
    font-family: var(--font-display);
    font-size: 12px;
    color: var(--accent-1);
    font-weight: 400;
}

/* Select */
.control-select {
    width: 100%;
    padding: 10px 14px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-family: var(--font-main);
    font-size: 13px;
    cursor: pointer;
    transition: border-color 0.2s;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
}

.control-select:hover,
.control-select:focus {
    border-color: var(--accent-1);
    outline: none;
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.control-select option {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

/* Slider */
.control-slider {
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: rgba(30, 41, 59, 0.8);
    appearance: none;
    outline: none;
    cursor: pointer;
}

.control-slider::-webkit-slider-thumb {
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--accent-gradient);
    border: 2px solid rgba(255, 255, 255, 0.2);
    cursor: pointer;
    box-shadow: 0 0 10px rgba(99, 102, 241, 0.5);
    transition: transform 0.15s ease;
}

.control-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.control-slider::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--accent-gradient);
    border: 2px solid rgba(255, 255, 255, 0.2);
    cursor: pointer;
    box-shadow: 0 0 10px rgba(99, 102, 241, 0.5);
}

/* Toggle Switch */
.toggle-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 0;
    font-size: 13px;
    color: var(--text-secondary);
    border-bottom: 1px solid rgba(99, 102, 241, 0.08);
}

.toggle-row:last-child {
    border-bottom: none;
}

.toggle-switch {
    position: relative;
    display: inline-block;
    width: 40px;
    height: 22px;
    flex-shrink: 0;
}

.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.toggle-slider {
    position: absolute;
    cursor: pointer;
    inset: 0;
    background: rgba(30, 41, 59, 0.8);
    border-radius: 22px;
    border: 1px solid var(--border-color);
    transition: all 0.3s;
}

.toggle-slider::before {
    content: '';
    position: absolute;
    height: 16px;
    width: 16px;
    left: 2px;
    bottom: 2px;
    background: var(--text-muted);
    border-radius: 50%;
    transition: all 0.3s;
}

.toggle-switch input:checked+.toggle-slider {
    background: rgba(99, 102, 241, 0.3);
    border-color: var(--accent-1);
}

.toggle-switch input:checked+.toggle-slider::before {
    transform: translateX(18px);
    background: var(--accent-1);
    box-shadow: 0 0 8px rgba(99, 102, 241, 0.5);
}

/* Subshell Buttons */
.subshell-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.subshell-btn {
    padding: 5px 10px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-card);
    color: var(--text-secondary);
    font-family: var(--font-main);
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    min-width: 36px;
    text-align: center;
}

.subshell-btn:hover {
    border-color: var(--accent-1);
    color: var(--text-primary);
    background: rgba(99, 102, 241, 0.1);
}

.subshell-btn.active {
    background: rgba(99, 102, 241, 0.2);
    border-color: var(--accent-1);
    color: var(--accent-1);
    box-shadow: 0 0 10px rgba(99, 102, 241, 0.15);
}

/* Color Scheme Buttons */
.color-scheme-options {
    display: flex;
    gap: 8px;
}

.color-btn {
    flex: 1;
    padding: 8px 4px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-card);
    color: var(--text-secondary);
    font-family: var(--font-main);
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.color-btn:hover {
    border-color: var(--accent-1);
    color: var(--text-primary);
}

.color-btn.active {
    background: rgba(99, 102, 241, 0.2);
    border-color: var(--accent-1);
    color: var(--accent-1);
    box-shadow: 0 0 12px rgba(99, 102, 241, 0.15);
}

/* Mode Toggle */
.mode-toggle {
    display: flex;
    gap: 4px;
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 3px;
}

.mode-btn {
    flex: 1;
    padding: 8px 12px;
    border: none;
    border-radius: 7px;
    background: transparent;
    color: var(--text-muted);
    font-family: var(--font-main);
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.mode-btn:hover {
    color: var(--text-secondary);
    background: rgba(99, 102, 241, 0.08);
}

.mode-btn.active {
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 2px 12px rgba(99, 102, 241, 0.4);
}

/* Bond Info Panel */
.bond-info {
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.bond-info strong {
    color: var(--accent-1);
    font-weight: 600;
}

/* Energy Level Diagram */
.energy-diagram-container {
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 2px;
    overflow: hidden;
}

.energy-diagram-container canvas {
    display: block;
    width: 100%;
}

/* Orbital Legend */
.orbital-legend {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 13px;
    color: var(--text-secondary);
}

.legend-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    box-shadow: 0 0 8px currentColor;
    flex-shrink: 0;
}

.legend-electrons {
    margin-left: auto;
    font-family: var(--font-display);
    font-size: 11px;
    color: var(--text-muted);
}

/* Reset Button */
.btn-reset {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-card);
    color: var(--text-secondary);
    font-family: var(--font-main);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.25s;
}

.btn-reset:hover {
    background: rgba(99, 102, 241, 0.15);
    border-color: var(--accent-1);
    color: var(--text-primary);
    box-shadow: var(--shadow-glow);
}

/* Info Tooltip */
.info-tooltip {
    position: fixed;
    z-index: 200;
    padding: 12px 18px;
    background: var(--bg-panel);
    border: 1px solid var(--border-glow);
    border-radius: var(--radius-md);
    backdrop-filter: blur(16px);
    box-shadow: var(--shadow-lg);
    font-size: 13px;
    color: var(--text-primary);
    pointer-events: none;
    max-width: 280px;
    transition: opacity 0.2s;
    line-height: 1.5;
}

.info-tooltip.hidden {
    opacity: 0;
    visibility: hidden;
}

.tooltip-content strong {
    color: var(--accent-1);
}

/* Instructions */
.instructions {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 100;
    animation: fade-in-up 0.6s ease 0.5s both;
}

@keyframes fade-in-up {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

.instruction-card {
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(16px);
    padding: 16px 24px;
    display: flex;
    align-items: center;
    gap: 20px;
}

.instruction-card h3 {
    font-family: var(--font-display);
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--text-muted);
    writing-mode: vertical-rl;
    text-orientation: mixed;
}

.instruction-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    font-size: 11px;
    color: var(--text-secondary);
}

.instruction-item .key {
    font-size: 16px;
}

/* Responsive */
@media (max-width: 768px) {
    #control-panel {
        width: 280px;
        right: 8px;
        top: 60px;
        bottom: 8px;
    }

    .logo h1 {
        font-size: 14px;
    }

    .element-display {
        padding: 6px 14px;
    }

    .element-symbol {
        font-size: 20px;
    }

    .config-banner {
        left: 12px;
        right: 12px;
        top: 54px;
        flex-wrap: wrap;
        padding: 8px 14px;
    }

    .config-text {
        font-size: 12px;
    }

    .instruction-card {
        padding: 12px 16px;
        gap: 14px;
    }
}