/* ==========================================================================
   Electrostatic Surface Calculator - Styles
   ========================================================================== */

:root {
    /* Colors */
    --bg-primary: #0a0a0a;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #2a2a2a;
    --color-text-primary: #e0e0e0;
    --color-text-secondary: #b0b0b0;
    --color-border: #333;
    --primary-color: #0dcaf0;
    --primary-hover: #0aa5c7;
    --success-color: #28a745;
    --warning-color: #ffc107;
    --error-color: #dc3545;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-md);
}

/* Header */
header {
    text-align: center;
    padding: var(--spacing-lg) 0;
    border-bottom: 1px solid var(--color-border);
    margin-bottom: var(--spacing-lg);
}

.header-content h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

#typing-text {
    color: var(--color-text-secondary);
    font-size: 1.1rem;
    min-height: 1.6em;
}

#typing-text::after {
    content: '|';
    animation: blink 1s infinite;
}

@keyframes blink {
    0%, 50% { opacity: 1; }
    51%, 100% { opacity: 0; }
}

nav {
    margin-top: var(--spacing-md);
}

.nav-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    border: 1px solid var(--primary-color);
    border-radius: 4px;
    transition: all 0.3s ease;
    display: inline-block;
}

.nav-link:hover {
    background: var(--primary-color);
    color: var(--bg-primary);
}

/* Main Grid */
.converter-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.converter-grid > button {
    grid-column: span 2;
}

.io-box {
    background: var(--bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    padding: var(--spacing-md);
}

.io-box h2 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

.io-box h3 {
    font-size: 1.1rem;
    margin: var(--spacing-md) 0 var(--spacing-sm) 0;
    color: var(--color-text-secondary);
}

/* Form Elements */
input[type="file"] {
    display: none;
}

.upload-btn {
    display: block;
    width: 100%;
    padding: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    background: var(--bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    color: var(--color-text-primary);
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
    font-weight: 500;
}

.upload-btn:hover {
    border-color: var(--primary-color);
    background: var(--primary-color);
    color: white;
}

textarea {
    width: 100%;
    padding: var(--spacing-sm);
    background: var(--bg-primary);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    color: var(--color-text-primary);
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    resize: vertical;
    transition: border-color 0.3s ease;
}

textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Parameters Box */
.params-box {
    background: var(--bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    padding: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.param-group {
    margin-bottom: var(--spacing-sm);
}

.param-group:last-child {
    margin-bottom: 0;
}

.param-group label {
    display: block;
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
    color: var(--color-text-secondary);
    font-size: 0.9rem;
}

.param-group input[type="number"],
.param-group select {
    width: 100%;
    padding: var(--spacing-xs);
    background: var(--bg-primary);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    color: var(--color-text-primary);
    font-size: 0.9rem;
    transition: border-color 0.3s ease;
}

.param-group input[type="number"]:focus,
.param-group select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.param-info {
    display: block;
    font-size: 0.75rem;
    color: var(--color-text-secondary);
    margin-top: 0.25rem;
    font-style: italic;
}

/* Status Box */
.status-box {
    background: var(--bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    padding: var(--spacing-md);
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.status-box.loading {
    border-color: var(--warning-color);
}

.status-box.success {
    border-color: var(--success-color);
}

.status-box.error {
    border-color: var(--error-color);
}

.status-box p {
    margin: 0;
    font-size: 0.95rem;
}

/* Viewer Controls */
.viewer-controls {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.control-button {
    padding: 8px 16px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: background 0.3s ease;
}

.control-button:hover {
    background: var(--primary-hover);
}

.control-button:active {
    transform: scale(0.98);
}

/* Output Controls */
.output-controls {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-sm);
}

.output-controls button {
    flex: 1;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--bg-tertiary);
    color: var(--color-text-primary);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.output-controls button:hover {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

/* Main Buttons */
#calculate-btn,
#clear-btn {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 1.1rem;
    font-weight: 600;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
}

#calculate-btn {
    background: linear-gradient(135deg, #0dcaf0 0%, #0d6efd 100%);
    color: white;
}

#calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(13, 202, 240, 0.3);
}

#calculate-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

#clear-btn {
    background: var(--bg-tertiary);
    color: var(--color-text-primary);
    border: 1px solid var(--color-border);
}

#clear-btn:hover {
    background: var(--bg-secondary);
    border-color: var(--primary-color);
}

/* Footer */
footer {
    text-align: center;
    padding: var(--spacing-lg) 0;
    border-top: 1px solid var(--color-border);
    margin-top: var(--spacing-lg);
    color: var(--color-text-secondary);
    font-size: 0.9rem;
}

footer a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

footer a:hover {
    color: var(--primary-hover);
}

/* Responsive */
@media (max-width: 768px) {
    .converter-grid {
        grid-template-columns: 1fr;
    }
    
    .converter-grid > button {
        grid-column: span 1;
    }
    
    .header-content h1 {
        font-size: 2rem;
    }
    
    #typing-text {
        font-size: 1rem;
    }
}

/* Loading Animation */
.loading-spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: var(--primary-color);
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}