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

:root {
    --primary-color: #0066cc;
    --success-color: #28a745;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
    --info-color: #17a2b8;
    --bg-color: #f8f9fa;
    --text-color: #333;
    --border-color: #dee2e6;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --container-bg: #ffffff;
    --card-bg: #ffffff;
    --output-bg: #111827;
    --output-text: #a7f3d0;
    --header-grad-1: #667eea;
    --header-grad-2: #764ba2;
}

[data-theme="dark"] {
    --primary-color: #3b82f6;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --info-color: #06b6d4;
    --bg-color: #1a1a2e;
    --text-color: #e5e7eb;
    --border-color: #374151;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
    --container-bg: #16213e;
    --card-bg: #0f3460;
    --output-bg: #0a0e27;
    --output-text: #6ee7b7;
    --header-grad-1: #1e3a8a;
    --header-grad-2: #581c87;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(var(--grad-angle, 135deg), var(--grad-c1, #667eea) 0%, var(--grad-c2, #764ba2) 100%);
    min-height: 100vh;
    padding: 20px;
    color: var(--text-color);
    transition: color 0.3s ease, background 0.5s ease;
    background-attachment: fixed;
    will-change: background;
    contain: layout style paint;
}

.bg-canvas {
    position: fixed;
    inset: 0;
    width: 100vw;
    height: 100vh;
    z-index: 0;
    pointer-events: none;
    contain: strict;
}

.container {
    position: relative;
    z-index: 1;
    max-width: 1200px;
    margin: 0 auto;
    background: var(--container-bg);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    transition: background 0.3s ease, box-shadow 0.3s ease;
    will-change: background;
}
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--header-grad-1) 0%, var(--header-grad-2) 100%);
    color: white;
    padding: 40px 20px;
    transition: background 0.3s ease;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;
}

.header-text {
    flex: 1;
    text-align: center;
}

.header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

.header .subtitle {
    font-size: 1.1rem;
    opacity: 0.95;
}

.header-buttons {
    display: flex;
    gap: 10px;
}

.btn-header {
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.btn-header:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1) rotate(10deg);
}

.header-icon,
.theme-icon {
    font-size: 1.5rem;
    transition: transform 0.3s ease;
}

.btn-header:active .header-icon,
.btn-header:active .theme-icon {
    transform: scale(0.9);
}

/* Sections - OPTIMIZED for reflow reduction */
section {
    padding: 30px 20px;
    transition: border-color 0.3s ease;
    contain: content;
}

section:last-child {
    border-bottom: none;
}

section h2 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 10px;
    transition: color 0.3s ease;
}

/* Info Section */
.info-section {
    background: var(--bg-color);
    transition: background 0.3s ease;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 15px;
}

.info-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 15px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    box-shadow: var(--shadow);
}

.info-card .label {
    font-size: 0.85rem;
    color: #666;
    font-weight: 600;
    text-transform: uppercase;
}

.info-card .value {
    font-size: 1rem;
    color: var(--primary-color);
    font-weight: 500;
    word-break: break-all;
}

.info-card .value.loading {
    color: #999;
    font-style: italic;
}

/* Main Section: two-column layout */
.main-section {
    background: var(--bg-color);
    transition: background 0.3s ease;
    contain: content;
}

.main-grid {
    display: grid;
    grid-template-columns: 1fr 1.4fr; /* Results pane larger */
    gap: 20px;
    align-items: start;
    contain: layout;
}

/* Horizontal module tabs */
.modules {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    transition: all 0.3s ease;
}

.module-tabs {
    display: flex;
    gap: 10px;
    padding: 12px;
    border-bottom: 1px solid var(--border-color);
    background: linear-gradient(135deg, rgba(102,126,234,0.08), rgba(118,75,162,0.08));
    transition: border-color 0.3s ease, background 0.3s ease;
}

.module-tab {
    flex: 1 1 auto;
    padding: 10px 12px;
    border: 1px solid transparent;
    border-radius: 8px;
    background: var(--container-bg);
    color: var(--text-color);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3
    transition: all 0.2s ease;
}

.module-tab:hover {
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.module-tab.active {
    border-color: var(--primary-color);
    color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

.module-panels {
    padding: 16px;
    contain: content;
}

.module-panel {
    display: none;
    animation: fadeIn 200ms ease-in;
}

.module-panel.active {
    display: block;
}

.module-panel h3 {
    transition: color 0.3s ease;
    margin-bottom: 12px;
    color: var(--text-color);
}

.btn-row {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.form-group {
    margin-bottom: 12px;
}

.input-field {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: var(--container-bg);
    color: var(--text-color);
    font-size: 1rem;
    transition: all 0.3s ease;
    font-family: inherit;
}

.input-field:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

/* Buttons - OPTIMIZED */
.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-right: 10px;
    margin-bottom: 10px;
    will-change: transform;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

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

.btn-primary:hover {
    background: #0052a3;
}

.btn-info {
    background: var(--info-color);
    color: white;
}

.btn-info:hover {
    background: #138496;
}

.btn-warning {
    background: var(--warning-color);
    color: #333;
}

.btn-warning:hover {
    background: #e0a800;
}

.btn-danger {
    background: var(--danger-color);
    color: white;
}

.btn-danger:hover {
    background: #c82333;
}

/* Result Section - OPTIMIZED */
.results {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    transition: background 0.3s ease, border-color 0.3s ease;
    contain: content;
}

.results h2 {
    margin-bottom: 12px;
}

.output-box {
    background: var(--output-bg);
    color: var(--output-text);
    padding: 24px;
    border-radius: 12px;
    overflow-x: auto;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
    font-size: 0.98rem;
    line-height: 1.7;
    border: 1px solid rgba(99, 102, 241, 0.3);
    min-height: 260px;
    max-height: 600px;
    contain: strict;
}
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.25);
    transition: all 0.3s ease
    max-height: 600px;
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.25);
}

.output-box.highlight {
    outline: 2px solid rgba(16, 185, 129, 0.7); /* Teal glow */
    outline-offset: 6px;
}

/* Toast Notifications */
.toast {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: #333;
    color: white;
    padding: 16px 24px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.3s ease;
    pointer-events: none;
    max-width: 400px;
    z-index: 1000;
}

.toast.show {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

.toast.success {
    background: var(--success-color);
}

.toast.error {
    background: var(--danger-color);
}

.toast.info {
    background: var(--info-color);
}

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

    .info-grid {
        grid-template-columns: 1fr;
    }

    section {
        padding: 20px 15px;
    }

    .btn {
        width: 100%;
        margin-right: 0;
    }
}

/* Loading animation */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.loading {
    animation: pulse 1.5s ease-in-out infinite;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(4px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* Credits Modal */
.modal {
    position: fixed;
    inset: 0;
    z-index: 2000;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.modal.active {
    display: flex;
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    animation: fadeIn 0.2s ease;
}

.modal-content {
    position: relative;
    background: var(--container-bg);
    border-radius: 16px;
    padding: 32px;
    max-width: 600px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    animation: slideUp 0.3s ease;
    transition: background 0.3s ease;
}

.modal-close {
    position: absolute;
    top: 16px;
    right: 16px;
    background: transparent;
    border: none;
    font-size: 2rem;
    color: var(--text-color);
    cursor: pointer;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: all 0.3s ease;
}

.modal-close:hover {
    background: var(--bg-color);
    transform: rotate(90deg);
}

.modal-content h2 {
    color: var(--primary-color);
    margin-bottom: 24px;
    font-size: 1.8rem;
    transition: color 0.3s ease;
}

.modal-content h3 {
    color: var(--text-color);
    margin-top: 20px;
    margin-bottom: 12px;
    font-size: 1.2rem;
    transition: color 0.3s ease;
}

.credits-section {
    margin-bottom: 20px;
}

.tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 12px;
    margin-top: 12px;
}

.tech-item {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 12px;
    text-align: center;
    transition: all 0.3s ease;
    text-decoration: none;
    display: flex;
    flex-direction: column;
    align-items: center;
    cursor: pointer;
    position: relative;
}

.tech-item::after {
    content: '→';
    position: absolute;
    top: 8px;
    right: 8px;
    opacity: 0;
    color: var(--primary-color);
    font-size: 1.2rem;
    transition: all 0.3s ease;
}

.tech-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow);
    border-color: var(--primary-color);
}

.tech-item:hover::after {
    opacity: 1;
    transform: translateX(4px);
}

.tech-logo {
    width: 48px;
    height: 48px;
    object-fit: contain;
    margin-bottom: 10px;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
    transition: transform 0.3s ease;
}

.tech-item:hover .tech-logo {
    transform: scale(1.1);
}

[data-theme="dark"] .tech-logo {
    filter: brightness(0.9) drop-shadow(0 2px 4px rgba(255, 255, 255, 0.1));
}

.tech-item strong {
    display: block;
    color: var(--text-color);
    font-size: 0.9rem;
    margin-bottom: 4px;
    transition: color 0.3s ease;
}

.tech-item small {
    color: #999;
    font-size: 0.75rem;
    transition: color 0.3s ease;
}

.tech-item:hover strong {
    color: var(--primary-color);
}

.features-list {
    list-style: none;
    padding: 0;
    margin: 12px 0;
}

.features-list li {
    padding: 8px 0;
    color: var(--text-color);
    transition: color 0.3s ease;
}

.credits-footer {
    text-align: center;
    color: var(--primary-color);
    font-style: italic;
    margin-top: 16px;
    transition: color 0.3s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive layout adjustments */
@media (max-width: 980px) {
    .main-grid {
        grid-template-columns: 1fr; /* Stack on small screens */
    }
    
    .modules {
        order: 2;
    }
    
    .results {
        order: 1;
        margin-bottom: 20px;
    }
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    .header {
        padding: 24px 16px;
    }

    .header-content {
        flex-direction: column;
        gap: 16px;
    }

    .header-text {
        text-align: center;
    }

    .header h1 {
        font-size: 1.8rem;
    }

    .header .subtitle {
        font-size: 0.95rem;
    }

    .header-buttons {
        justify-content: center;
    }

    .info-grid {
        grid-template-columns: 1fr;
    }

    section {
        padding: 20px 15px;
    }

    .module-tabs {
        flex-wrap: wrap;
        gap: 6px;
        padding: 8px;
    }

    .module-tab {
        flex: 1 1 calc(50% - 6px);
        font-size: 0.9rem;
        padding: 8px;
    }

    .btn {
        width: 100%;
        margin-right: 0;
    }

    .btn-row {
        flex-direction: column;
    }

    .btn-row .btn {
        width: 100%;
    }

    .output-box {
        font-size: 0.85rem;
        padding: 16px;
        max-height: 300px;
    }

    .modal-content {
        padding: 24px;
        margin: 10px;
    }

    .modal-content h2 {
        font-size: 1.5rem;
    }

    .tech-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 1.5rem;
    }

    .header .subtitle {
        font-size: 0.85rem;
    }

    .btn-header {
        width: 42px;
        height: 42px;
    }

    .header-icon,
    .theme-icon {
        font-size: 1.3rem;
    }

    .module-tab {
        flex: 1 1 100%;
        text-align: center;
    }

    .info-card {
        padding: 12px;
    }

    .tech-grid {
        grid-template-columns: 1fr;
    }

    .modal-content {
        padding: 20px;
    }

    .modal-close {
        top: 12px;
        right: 12px;
        width: 36px;
        height: 36px;
        font-size: 1.5rem;
    }
}

@media (max-width: 360px) {
    body {
        padding: 5px;
    }

    .header {
        padding: 20px 12px;
    }

    .header h1 {
        font-size: 1.3rem;
    }

    section {
        padding: 16px 12px;
    }

    .output-box {
        padding: 12px;
        font-size: 0.8rem;
    }
}