/* CSS Reset and Base Styles */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --success-color: #16a34a;
    --success-bg: #dcfce7;
    --error-color: #dc2626;
    --error-bg: #fee2e2;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-primary: #f9fafb;
    --bg-card: #ffffff;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
}

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

.app-container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 32px;
}

header h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
}

header .subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Main Content */
main {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* Sections */
section {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-md);
}

section h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--text-primary);
}

/* Color Inputs Section */
.color-inputs {
    display: flex;
    gap: 20px;
    align-items: flex-end;
    flex-wrap: wrap;
}

.color-input-group {
    flex: 1;
    min-width: 200px;
}

.color-input-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.color-picker-wrapper {
    display: flex;
    gap: 8px;
    align-items: center;
}

input[type="color"] {
    width: 48px;
    height: 48px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    padding: 2px;
    background: var(--bg-card);
}

input[type="color"]::-webkit-color-swatch-wrapper {
    padding: 0;
}

input[type="color"]::-webkit-color-swatch {
    border: none;
    border-radius: 4px;
}

input[type="text"] {
    flex: 1;
    height: 48px;
    padding: 0 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: 'SF Mono', Monaco, Consolas, monospace;
    text-transform: uppercase;
    transition: border-color 0.2s, box-shadow 0.2s;
}

input[type="text"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

input[type="text"].invalid {
    border-color: var(--error-color);
}

.swap-btn {
    width: 48px;
    height: 48px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-card);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all 0.2s;
}

.swap-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    background: rgba(37, 99, 235, 0.05);
}

/* Preview Section */
.preview-section {
    padding: 0;
    overflow: hidden;
}

.preview-box {
    padding: 32px;
    border-radius: var(--radius-lg);
    transition: background-color 0.3s, color 0.3s;
}

.preview-text-large {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 12px;
}

.preview-text-normal {
    font-size: 16px;
    line-height: 1.6;
}

/* Contrast Section */
.contrast-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contrast-ratio {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
}

.contrast-ratio .label {
    font-weight: 500;
    color: var(--text-secondary);
}

.ratio-value {
    font-size: 1.5rem;
    font-weight: 700;
    font-family: 'SF Mono', Monaco, Consolas, monospace;
}

.ratio-value.pass {
    color: var(--success-color);
}

.ratio-value.fail {
    color: var(--error-color);
}

.wcag-compliance h3 {
    margin-bottom: 12px;
}

.compliance-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.compliance-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 16px;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
}

.compliance-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.compliance-status {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 4px 12px;
    border-radius: 20px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.compliance-status.pass {
    background: var(--success-bg);
    color: var(--success-color);
}

.compliance-status.fail {
    background: var(--error-bg);
    color: var(--error-color);
}

/* Adjust Section */
.adjust-section .adjust-description {
    color: var(--text-secondary);
    margin-bottom: 20px;
    font-size: 0.875rem;
}

.adjust-buttons {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.adjust-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.adjust-group h4 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.adjust-btn {
    padding: 10px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    text-align: left;
}

.adjust-btn:hover {
    border-color: var(--primary-color);
    background: rgba(37, 99, 235, 0.05);
}

.adjust-btn:active {
    transform: scale(0.98);
}

.adjust-btn.success {
    border-color: var(--success-color);
    background: var(--success-bg);
}

/* Suggestions Section */
.suggestions-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 12px;
}

.suggestion-item {
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    text-align: center;
    transition: all 0.2s;
}

.suggestion-item:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.suggestion-color {
    width: 100%;
    height: 40px;
    border-radius: var(--radius-sm);
    margin-bottom: 8px;
}

.suggestion-hex {
    font-family: 'SF Mono', Monaco, Consolas, monospace;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.suggestion-ratio {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--success-color);
    margin-top: 4px;
}

/* Info Section */
.info-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.info-card {
    padding: 16px;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
}

.info-card h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--primary-color);
}

.info-card ul {
    list-style: none;
    margin-bottom: 12px;
}

.info-card li {
    font-size: 0.875rem;
    margin-bottom: 4px;
    color: var(--text-primary);
}

.info-note {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-style: italic;
}

/* Footer */
footer {
    text-align: center;
    padding: 24px;
    margin-top: 32px;
    border-top: 1px solid var(--border-color);
}

footer p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

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

/* Mobile Responsive */
@media (max-width: 768px) {
    .app-container {
        padding: 16px;
    }

    header h1 {
        font-size: 1.5rem;
    }

    section {
        padding: 16px;
    }

    .color-inputs {
        flex-direction: column;
        align-items: stretch;
    }

    .color-input-group {
        min-width: 100%;
    }

    .swap-btn {
        align-self: center;
        transform: rotate(90deg);
    }

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

    .adjust-buttons {
        grid-template-columns: 1fr;
    }

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

    .preview-box {
        padding: 20px;
    }

    .preview-text-large {
        font-size: 20px;
    }

    .preview-text-normal {
        font-size: 14px;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.25rem;
    }

    .contrast-ratio {
        flex-direction: column;
        gap: 8px;
        text-align: center;
    }

    .ratio-value {
        font-size: 2rem;
    }

    .compliance-item {
        flex-direction: column;
        gap: 8px;
        text-align: center;
    }
}

/* Animations */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.7;
    }
}

.updating {
    animation: pulse 0.5s ease-in-out;
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for keyboard navigation */
button:focus-visible,
input:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}