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

:root {
    /* Color Palette */
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-light: #dbeafe;

    --critical-color: #dc2626;
    --critical-bg: #fef2f2;
    --serious-color: #ea580c;
    --serious-bg: #fff7ed;
    --moderate-color: #ca8a04;
    --moderate-bg: #fefce8;
    --minor-color: #16a34a;
    --minor-bg: #f0fdf4;

    --success-color: #16a34a;
    --warning-color: #ca8a04;
    --error-color: #dc2626;

    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;

    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;

    --border-color: #e5e7eb;
    --border-radius: 12px;
    --border-radius-sm: 8px;

    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);

    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --transition: all 0.2s ease-in-out;
}

/* Screen reader only utility */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header Styles */
header {
    text-align: center;
    margin-bottom: 2rem;
    color: white;
}

.logo-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

.logo {
    width: 48px;
    height: 48px;
    object-fit: contain;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.tagline {
    font-size: 1.125rem;
    opacity: 0.9;
}

/* Main Content */
main {
    flex: 1;
}

/* Input Section */
.input-section {
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    margin-bottom: 2rem;
}

.input-group {
    display: flex;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

#url-input {
    flex: 1;
    padding: 1rem 1.25rem;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    transition: var(--transition);
    outline: none;
}

#url-input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

#url-input::placeholder {
    color: var(--text-light);
}

#check-btn {
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    color: white;
    background: var(--primary-color);
    border: none;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

#check-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow);
}

#check-btn:active {
    transform: translateY(0);
}

#check-btn:disabled {
    background: var(--text-light);
    cursor: not-allowed;
    transform: none;
}

#check-btn .btn-loading {
    display: none;
}

#check-btn.loading .btn-text {
    display: none;
}

#check-btn.loading .btn-loading {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.spinner {
    width: 18px;
    height: 18px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

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

/* Results Section */
.results-section {
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    margin-bottom: 2rem;
}

.results-section.hidden {
    display: none;
}

.results-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.results-header h2 {
    font-size: 1.75rem;
    color: var(--text-primary);
}

.score-container {
    display: flex;
    align-items: center;
}

.score-circle {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: conic-gradient(var(--success-color) 0deg, var(--bg-tertiary) 0deg);
    position: relative;
}

.score-circle::before {
    content: '';
    position: absolute;
    width: 80px;
    height: 80px;
    background: var(--bg-primary);
    border-radius: 50%;
}

.score-value {
    position: relative;
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
}

.score-label {
    position: relative;
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Summary Cards */
.summary-cards {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
    margin-bottom: 2rem;
}

.summary-card {
    padding: 1.5rem;
    border-radius: var(--border-radius-sm);
    text-align: center;
    transition: var(--transition);
}

.summary-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.summary-card.critical {
    background: var(--critical-bg);
    border: 1px solid var(--critical-color);
}

.summary-card.critical .card-count {
    color: var(--critical-color);
}

.summary-card.serious {
    background: var(--serious-bg);
    border: 1px solid var(--serious-color);
}

.summary-card.serious .card-count {
    color: var(--serious-color);
}

.summary-card.moderate {
    background: var(--moderate-bg);
    border: 1px solid var(--moderate-color);
}

.summary-card.moderate .card-count {
    color: var(--moderate-color);
}

.summary-card.minor {
    background: var(--minor-bg);
    border: 1px solid var(--minor-color);
}

.summary-card.minor .card-count {
    color: var(--minor-color);
}

.card-count {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    line-height: 1;
    margin-bottom: 0.25rem;
}

.card-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* WCAG Compliance */
.wcag-compliance {
    margin-bottom: 2rem;
}

.wcag-compliance h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.compliance-badges {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.compliance-badge {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1.25rem;
    background: var(--bg-tertiary);
    border-radius: var(--border-radius-sm);
    border: 2px solid var(--border-color);
    transition: var(--transition);
}

.compliance-badge.pass {
    background: var(--minor-bg);
    border-color: var(--success-color);
}

.compliance-badge.fail {
    background: var(--critical-bg);
    border-color: var(--error-color);
}

.badge-icon {
    font-size: 1.25rem;
    font-weight: 700;
}

.compliance-badge.pass .badge-icon {
    color: var(--success-color);
}

.compliance-badge.fail .badge-icon {
    color: var(--error-color);
}

.badge-label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* Filter Controls */
.filter-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius-sm);
}

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

#severity-filter {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    background: var(--bg-primary);
    cursor: pointer;
    outline: none;
}

#severity-filter:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px var(--primary-light);
}

/* Violations List */
.violations-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.violation-card {
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    overflow: hidden;
    transition: var(--transition);
}

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

.violation-card.critical {
    border-left: 4px solid var(--critical-color);
}

.violation-card.serious {
    border-left: 4px solid var(--serious-color);
}

.violation-card.moderate {
    border-left: 4px solid var(--moderate-color);
}

.violation-card.minor {
    border-left: 4px solid var(--minor-color);
}

.violation-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    padding: 1rem 1.25rem;
    background: var(--bg-secondary);
    cursor: pointer;
    gap: 1rem;
}

.violation-header:hover {
    background: var(--bg-tertiary);
}

.violation-title {
    flex: 1;
}

.violation-title h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.violation-meta {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.severity-badge {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    text-transform: uppercase;
}

.severity-badge.critical {
    background: var(--critical-bg);
    color: var(--critical-color);
}

.severity-badge.serious {
    background: var(--serious-bg);
    color: var(--serious-color);
}

.severity-badge.moderate {
    background: var(--moderate-bg);
    color: var(--moderate-color);
}

.severity-badge.minor {
    background: var(--minor-bg);
    color: var(--minor-color);
}

.wcag-tag {
    font-size: 0.75rem;
    font-weight: 500;
    padding: 0.25rem 0.5rem;
    background: var(--primary-light);
    color: var(--primary-color);
    border-radius: 4px;
}

.expand-icon {
    font-size: 1.25rem;
    color: var(--text-secondary);
    transition: var(--transition);
}

.violation-card.expanded .expand-icon {
    transform: rotate(180deg);
}

.violation-body {
    display: none;
    padding: 1.25rem;
    border-top: 1px solid var(--border-color);
}

.violation-card.expanded .violation-body {
    display: block;
}

.violation-description {
    margin-bottom: 1rem;
}

.violation-description h5 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.violation-description p {
    color: var(--text-primary);
    line-height: 1.6;
}

.violation-fix {
    background: var(--bg-secondary);
    padding: 1rem;
    border-radius: var(--border-radius-sm);
    margin-bottom: 1rem;
}

.violation-fix h5 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--success-color);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.violation-fix p {
    color: var(--text-primary);
    line-height: 1.6;
}

.violation-elements {
    margin-top: 1rem;
}

.violation-elements h5 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.element-item {
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.8rem;
    background: var(--bg-tertiary);
    padding: 0.5rem 0.75rem;
    border-radius: 4px;
    margin-bottom: 0.5rem;
    overflow-x: auto;
    color: var(--text-primary);
}

/* Error Section */
.error-section {
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    padding: 3rem 2rem;
    box-shadow: var(--shadow-lg);
    margin-bottom: 2rem;
    text-align: center;
}

.error-section.hidden {
    display: none;
}

.error-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.error-content h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.error-content p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.retry-btn {
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    color: white;
    background: var(--primary-color);
    border: none;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

.retry-btn:hover {
    background: var(--primary-hover);
}

/* Info Section */
.info-section {
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    margin-bottom: 2rem;
}

.info-section h2 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    text-align: center;
}

.info-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.info-card {
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius-sm);
}

.info-card h3 {
    font-size: 1.125rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.info-card p {
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    line-height: 1.6;
}

.info-card ul {
    list-style: none;
    padding: 0;
}

.info-card li {
    padding: 0.375rem 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 1.25rem;
}

.info-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: bold;
}

/* Footer */
footer {
    margin-top: auto;
    padding-top: 2rem;
}

.footer-content {
    text-align: center;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    backdrop-filter: blur(10px);
}

.powered-by {
    font-size: 1rem;
    color: white;
    margin-bottom: 0.5rem;
}

.powered-by a {
    color: white;
    font-weight: 600;
    text-decoration: underline;
    transition: var(--transition);
}

.powered-by a:hover {
    opacity: 0.8;
}

.copyright {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.7);
}

/* No Violations State */
.no-violations {
    text-align: center;
    padding: 3rem 2rem;
    background: var(--minor-bg);
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--success-color);
}

.no-violations-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.no-violations h4 {
    font-size: 1.25rem;
    color: var(--success-color);
    margin-bottom: 0.5rem;
}

.no-violations p {
    color: var(--text-secondary);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .info-cards {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    h1 {
        font-size: 1.75rem;
    }

    .tagline {
        font-size: 1rem;
    }

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

    #check-btn {
        width: 100%;
        justify-content: center;
    }

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

    .results-header {
        flex-direction: column;
        text-align: center;
    }

    .compliance-badges {
        justify-content: center;
    }

    .filter-controls {
        flex-direction: column;
        align-items: stretch;
    }

    #severity-filter {
        width: 100%;
    }

    .violation-header {
        flex-direction: column;
    }

    .violation-meta {
        margin-top: 0.5rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 1rem 0.75rem;
    }

    .input-section,
    .results-section,
    .error-section,
    .info-section {
        padding: 1.25rem;
    }

    .summary-cards {
        grid-template-columns: 1fr 1fr;
        gap: 0.75rem;
    }

    .summary-card {
        padding: 1rem;
    }

    .card-count {
        font-size: 1.5rem;
    }

    .score-circle {
        width: 80px;
        height: 80px;
    }

    .score-circle::before {
        width: 64px;
        height: 64px;
    }

    .score-value {
        font-size: 1.5rem;
    }

    .logo-container {
        flex-direction: column;
        gap: 0.5rem;
    }
}

/* Print Styles */
@media print {
    body {
        background: white;
    }

    .container {
        max-width: 100%;
    }

    header {
        color: black;
    }

    .input-section,
    .info-section,
    footer {
        display: none;
    }

    .results-section {
        box-shadow: none;
        border: 1px solid var(--border-color);
    }

    .violation-card.expanded .violation-body {
        display: block;
    }
}