:root {
    --bg-primary: #f8f9fa;
    --bg-secondary: #ffffff;
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(255, 255, 255, 0.5);
    --text-primary: #1a1a1a;
    --text-secondary: #4a5568;
    --text-muted: #718096;
    --accent-primary: #3b82f6;
    --accent-hover: #2563eb;
    --accent-success: #10b981;
    --accent-success-hover: #059669;
    --accent-warning: #f59e0b;
    --accent-danger: #ef4444;
    --border-color: rgba(0, 0, 0, 0.08);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --radius: 30px;
    --radius-md: 20px;
    --radius-sm: 15px;
}

[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --accent-primary: #60a5fa;
    --accent-hover: #3b82f6;
    --accent-success: #34d399;
    --accent-success-hover: #10b981;
    --accent-warning: #fbbf24;
    --accent-danger: #f87171;
    --border-color: rgba(255, 255, 255, 0.1);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
}

* {
    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(--text-primary);
    line-height: 1.6;
    padding: 40px 20px;
    transition: background 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
}

.card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-radius: var(--radius);
    border: 1px solid var(--glass-border);
    padding: 35px;
    margin-bottom: 25px;
    box-shadow: var(--shadow-md);
    transition: box-shadow 0.2s ease;
}

.card:hover {
    box-shadow: var(--shadow-lg);
}

header {
    text-align: center;
    margin-bottom: 40px;
}

h1 {
    font-size: 2.8em;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text-primary);
    letter-spacing: -0.5px;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1em;
    font-weight: 400;
}

.theme-toggle {
    position: fixed;
    top: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 1.4em;
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    z-index: 1000;
}

.theme-toggle:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

label {
    display: block;
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--text-primary);
    font-size: 1.05em;
}

textarea,
input[type="number"] {
    width: 100%;
    padding: 16px 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1em;
    color: var(--text-primary);
    font-family: 'SF Mono', 'Monaco', 'Courier New', monospace;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
    resize: vertical;
}

textarea:focus,
input[type="number"]:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

textarea {
    min-height: 180px;
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 18px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    margin-bottom: 16px;
}

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

.checkbox-group label {
    margin: 0;
    cursor: pointer;
    user-select: none;
    font-size: 1em;
    font-weight: 500;
}

.button-group {
    display: flex;
    gap: 12px;
    margin-top: 16px;
}

.btn {
    padding: 14px 28px;
    font-size: 1em;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: inherit;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--accent-primary);
    color: white;
    flex: 1;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.2);
}

.btn-primary:hover:not(:disabled) {
    background: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(59, 130, 246, 0.3);
}

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

.btn-secondary:hover:not(:disabled) {
    background: var(--bg-primary);
}

.btn-success {
    background: var(--accent-success);
    color: white;
    width: 100%;
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.2);
}

.btn-success:hover:not(:disabled) {
    background: var(--accent-success-hover);
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(16, 185, 129, 0.3);
}

.output-box {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
    min-height: 150px;
    max-height: 400px;
    overflow-y: auto;
    font-family: Georgia, 'Times New Roman', serif;
    font-size: 1.1em;
    line-height: 1.8;
    color: var(--text-secondary);
}

.placeholder {
    color: var(--text-muted);
    font-style: italic;
    text-align: center;
    padding: 30px;
}

.restart {
    background: rgba(239, 68, 68, 0.1);
    color: var(--accent-danger);
    font-weight: 600;
    padding: 3px 8px;
    border-radius: 8px;
    display: inline-block;
    margin: 0 2px;
    border: 1px solid rgba(239, 68, 68, 0.2);
}

[data-theme="dark"] .restart {
    background: rgba(248, 113, 113, 0.15);
    color: var(--accent-danger);
    border-color: rgba(248, 113, 113, 0.3);
}

.restart-tag {
    background: var(--accent-warning);
    color: white;
    font-weight: 700;
    padding: 4px 12px;
    border-radius: 12px;
    display: inline-block;
    margin: 0 6px;
    font-size: 0.85em;
    box-shadow: 0 2px 8px rgba(245, 158, 11, 0.3);
}

[data-theme="dark"] .restart-tag {
    background: var(--accent-warning);
    box-shadow: 0 2px 8px rgba(251, 191, 36, 0.4);
}

.paragraph-label {
    background: rgba(239, 68, 68, 0.1);
    color: var(--accent-danger);
    font-weight: 700;
    padding: 4px 10px;
    border-radius: 8px;
    display: inline-block;
    margin-right: 8px;
    border: 1px solid rgba(239, 68, 68, 0.2);
}

[data-theme="dark"] .paragraph-label {
    background: rgba(248, 113, 113, 0.15);
    color: var(--accent-danger);
    border-color: rgba(248, 113, 113, 0.3);
}

.restart-stats {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.95em;
    font-family: 'Inter', sans-serif;
}

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

.stats-section h3 {
    margin-bottom: 20px;
    color: var(--text-primary);
    font-size: 1.4em;
    font-weight: 600;
}

.top-transitions {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.transition-item {
    background: var(--bg-secondary);
    padding: 16px 20px;
    border-radius: var(--radius-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid var(--border-color);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.transition-item:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow-sm);
}

.transition-words {
    font-weight: 600;
    color: var(--text-primary);
}

.transition-arrow {
    color: var(--accent-primary);
    margin: 0 10px;
    font-size: 1.2em;
}

.transition-count {
    background: var(--accent-primary);
    color: white;
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.9em;
    font-weight: 600;
}

.collapsible-header {
    background: var(--bg-secondary);
    padding: 18px 24px;
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.2s ease;
    user-select: none;
    border: 1px solid var(--border-color);
}

.collapsible-header:hover {
    background: var(--bg-primary);
}

.collapsible-header h3 {
    margin: 0;
    font-size: 1.3em;
    font-weight: 600;
}

.toggle-icon {
    font-size: 1.2em;
    transition: transform 0.2s ease;
    color: var(--text-muted);
}

.collapsible-header.collapsed .toggle-icon {
    transform: rotate(-90deg);
}

.collapsible-content {
    max-height: 2000px;
    overflow: hidden;
    transition: max-height 0.3s ease, opacity 0.3s ease;
    opacity: 1;
    margin-top: 16px;
}

.collapsible-content.collapsed {
    max-height: 0;
    opacity: 0;
    margin-top: 0;
}

.table-container {
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    padding: 20px;
    border: 1px solid var(--border-color);
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    font-size: 0.95em;
}

thead {
    background: var(--accent-primary);
    color: white;
}

thead tr th:first-child {
    border-top-left-radius: var(--radius-sm);
}

thead tr th:last-child {
    border-top-right-radius: var(--radius-sm);
}

th, td {
    padding: 14px 16px;
    text-align: left;
}

th {
    font-weight: 600;
}

tbody tr {
    border-bottom: 1px solid var(--border-color);
}

tbody tr:hover {
    background: var(--bg-primary);
}

.probability-bar {
    background: var(--border-color);
    height: 6px;
    border-radius: 10px;
    overflow: hidden;
    margin-top: 6px;
}

.probability-fill {
    background: var(--accent-success);
    height: 100%;
    border-radius: 10px;
    transition: width 0.3s ease;
}

.diagram-info {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 16px;
    font-size: 0.95em;
}

#stateCanvas {
    display: block;
    margin: 0 auto;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    max-width: 100%;
    height: auto;
}

footer {
    text-align: center;
    margin-top: 40px;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.95em;
}

::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
    border-radius: 10px;
}

::-webkit-scrollbar-thumb {
    background: var(--accent-primary);
    border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-hover);
}

.notification {
    position: fixed;
    top: 30px;
    right: 30px;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    color: var(--text-primary);
    padding: 16px 24px;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--glass-border);
    z-index: 2000;
    font-weight: 500;
}

@media (max-width: 768px) {
    body {
        padding: 20px 15px;
    }

    .card {
        padding: 25px;
    }

    h1 {
        font-size: 2.2em;
    }

    .button-group {
        flex-direction: column;
    }

    .theme-toggle {
        top: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
        font-size: 1.2em;
    }

    #stateCanvas {
        width: 100% !important;
        height: auto !important;
    }
}

.control-group {
    margin-bottom: 16px;
}