/* Modern UI Styles for Symbolic Learning */

:root {
    --bg-primary: #0f0f0f;
    --bg-secondary: #1a1a1a;
    --bg-card: #242424;
    --bg-input: #333333;
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --text-muted: #666666;
    --accent-primary: #007aff;
    --accent-success: #34c759;
    --accent-warning: #ff9500;
    --accent-danger: #ff3b30;
    --border-color: #333333;
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
    --radius: 12px;
    --radius-sm: 8px;
}

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

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

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
.header {
    text-align: center;
    padding: 40px 20px;
    margin-bottom: 30px;
}

.header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(
        135deg,
        var(--accent-primary),
        var(--accent-success)
    );
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 10px;
}

.header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Card Styles */
.card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 24px;
    margin-bottom: 20px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 10px;
}

.card-title::before {
    content: "";
    width: 4px;
    height: 20px;
    background: var(--accent-primary);
    border-radius: 2px;
}

/* Equation Builder */
.equation-builder {
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    padding: 20px;
    margin-bottom: 20px;
}

.equation-display {
    font-size: 1.3rem;
    font-family: "SF Mono", Monaco, "Courier New", monospace;
    color: var(--text-primary);
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    justify-content: center;
    padding: 15px;
    background: var(--bg-input);
    border-radius: var(--radius-sm);
}

.equation-display .symbol {
    color: var(--text-secondary);
}

.equation-display .func {
    color: var(--accent-warning);
    font-weight: 500;
}

/* Equation Input */
.equation-input-wrapper {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 15px;
}

.equation-label {
    font-size: 1.3rem;
    font-family: "SF Mono", Monaco, monospace;
    color: var(--text-secondary);
    min-width: 40px;
}

.equation-input {
    flex: 1;
    padding: 12px 16px;
    font-size: 1.1rem;
    font-family: "SF Mono", Monaco, monospace;
    background: var(--bg-input);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    transition: all 0.2s ease;
}

.equation-input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.2);
}

.equation-input:hover {
    border-color: var(--text-muted);
}

.equation-input::placeholder {
    color: var(--text-muted);
    font-style: italic;
}

/* Help Text */
.help-text {
    background: var(--bg-primary);
    padding: 12px;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
    border-left: 3px solid var(--accent-primary);
}

.help-text strong {
    color: var(--text-primary);
}

/* Number Inputs (kept for backwards compatibility) */
input[type="number"] {
    width: 60px;
    padding: 8px 12px;
    font-size: 1rem;
    font-family: "SF Mono", Monaco, monospace;
    background: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--accent-primary);
    text-align: center;
    transition: all 0.2s ease;
    -moz-appearance: textfield;
}

input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

input[type="number"]:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.2);
}

input[type="number"]:hover {
    border-color: var(--text-muted);
}

/* Buttons */
.btn-group {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 20px;
}

.btn {
    padding: 12px 24px;
    font-size: 0.95rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-primary), #0056b3);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 122, 255, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: var(--bg-input);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--border-color);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

/* Checkbox */
.checkbox-wrapper {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-top: 15px;
    padding: 10px;
    background: var(--bg-input);
    border-radius: var(--radius-sm);
    cursor: pointer;
}

.checkbox-wrapper input[type="checkbox"] {
    width: 20px;
    height: 20px;
    accent-color: var(--accent-primary);
    cursor: pointer;
}

.checkbox-wrapper label {
    color: var(--text-secondary);
    font-size: 0.9rem;
    cursor: pointer;
}

/* Results Section */
.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-bottom: 20px;
}

.result-item {
    background: var(--bg-secondary);
    padding: 16px;
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--accent-primary);
}

.result-item.success {
    border-left-color: var(--accent-success);
}

.result-item.warning {
    border-left-color: var(--accent-warning);
}

.result-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 5px;
}

.result-value {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    font-family: "SF Mono", Monaco, monospace;
    word-break: break-all;
}

/* Video Container */
.video-container {
    background: var(--bg-secondary);
    border-radius: var(--radius);
    overflow: hidden;
    position: relative;
}

.video-container video {
    width: 100%;
    height: auto;
    display: block;
}

#full_plot {
    min-height: 300px;
    display: flex;
    align-items: center;
    justify-content: center;
}

#full_plot:empty::after {
    content: "Visualization will appear here";
    color: var(--text-muted);
    font-style: italic;
}

/* Layout Grid */
.main-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

@media (max-width: 992px) {
    .main-grid {
        grid-template-columns: 1fr;
    }
}

/* Loading Overlay */
#hider {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.85);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

#hider.active {
    opacity: 1;
    pointer-events: all;
}

#loader {
    width: 60px;
    height: 60px;
    border: 4px solid var(--bg-card);
    border-top-color: var(--accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

#loader-text {
    margin-top: 20px;
    color: var(--text-secondary);
    font-size: 1rem;
}

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

/* About Section */
.about-section {
    margin-top: 30px;
}

.about-section summary {
    cursor: pointer;
    padding: 15px;
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-weight: 500;
    list-style: none;
    display: flex;
    align-items: center;
    gap: 10px;
}

.about-section summary::-webkit-details-marker {
    display: none;
}

.about-section summary::before {
    content: "▶";
    font-size: 0.7rem;
    transition: transform 0.2s;
}

.about-section[open] summary::before {
    transform: rotate(90deg);
}

.about-section .content {
    padding: 20px;
    color: var(--text-secondary);
    line-height: 1.8;
}

.about-section .content p {
    margin-bottom: 15px;
}

/* Stats badges */
.stats-row {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-top: 10px;
}

.stat-badge {
    background: var(--bg-input);
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.stat-badge strong {
    color: var(--accent-primary);
}

/* Responsive */
@media (max-width: 768px) {
    .header h1 {
        font-size: 1.8rem;
    }

    .equation-display {
        font-size: 1rem;
    }

    input[type="number"] {
        width: 50px;
        padding: 6px 8px;
    }

    .btn {
        padding: 10px 16px;
        font-size: 0.85rem;
    }

    .btn-group {
        justify-content: center;
    }
}