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

:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --background: #f8fafc;
    --surface: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --transition: all 0.2s ease;
}

html {
    font-size: 16px;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header Styles */
header {
    text-align: center;
    padding: 40px 20px;
}

.logo-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-bottom: 12px;
}

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

h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    background: linear-gradient(135deg, var(--primary-color), #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-top: 8px;
}

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

/* Input Section */
.input-section {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow-md);
    margin-bottom: 32px;
}

.url-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin-bottom: 24px;
}

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

.input-group label {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.input-group input {
    padding: 14px 18px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: var(--transition);
    background: var(--surface);
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

.input-group input::placeholder {
    color: var(--secondary-color);
}

/* Buttons */
.primary-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    width: 100%;
    padding: 16px 32px;
    background: linear-gradient(135deg, var(--primary-color), #8b5cf6);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.primary-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.primary-btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

.secondary-btn {
    padding: 12px 24px;
    background: var(--surface);
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

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

.cors-notice {
    margin-top: 16px;
    padding: 12px 16px;
    background: #fef3c7;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    color: #92400e;
}

/* Spinner */
.spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    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); }
}

.hidden {
    display: none !important;
}

/* Results Section */
.results-section {
    animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Similarity Score */
.similarity-score {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow-md);
    text-align: center;
    margin-bottom: 24px;
}

.similarity-score h2 {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.score-display {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
}

.score-circle {
    position: relative;
    width: 160px;
    height: 160px;
}

.score-circle svg {
    transform: rotate(-90deg);
    width: 100%;
    height: 100%;
}

.score-circle circle {
    fill: none;
    stroke-width: 8;
    stroke-linecap: round;
}

.score-bg {
    stroke: var(--border-color);
}

.score-fill {
    stroke: var(--primary-color);
    stroke-dasharray: 283;
    stroke-dashoffset: 283;
    transition: stroke-dashoffset 1s ease, stroke 0.3s ease;
}

.score-value {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

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

/* Breakdown Section */
.breakdown-section {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-md);
    margin-bottom: 24px;
}

.breakdown-section h3 {
    font-size: 1.1rem;
    color: var(--text-primary);
    margin-bottom: 20px;
}

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

.breakdown-item {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.breakdown-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.progress-bar {
    height: 8px;
    background: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), #8b5cf6);
    border-radius: 4px;
    width: 0%;
    transition: width 0.8s ease;
}

.breakdown-value {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* Details Section */
.details-section {
    background: var(--surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
}

/* Tabs */
.tabs {
    display: flex;
    border-bottom: 1px solid var(--border-color);
    background: #f1f5f9;
}

.tab-btn {
    flex: 1;
    padding: 16px 24px;
    background: transparent;
    border: none;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}

.tab-btn:hover {
    color: var(--primary-color);
    background: rgba(99, 102, 241, 0.05);
}

.tab-btn.active {
    color: var(--primary-color);
    background: var(--surface);
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--primary-color);
}

.tab-content {
    display: none;
    padding: 24px;
}

.tab-content.active {
    display: block;
}

/* Keywords Tab */
.keywords-comparison {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.keyword-column h4 {
    font-size: 0.95rem;
    color: var(--text-primary);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--border-color);
}

.keyword-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    max-height: 300px;
    overflow-y: auto;
}

.keyword-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: #f1f5f9;
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--text-primary);
}

.keyword-tag.common {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.15), rgba(139, 92, 246, 0.15));
    color: var(--primary-color);
}

.keyword-count {
    font-size: 0.75rem;
    background: rgba(0, 0, 0, 0.1);
    padding: 2px 6px;
    border-radius: 10px;
}

/* Content Tab */
.content-comparison {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.content-column h4 {
    font-size: 0.95rem;
    color: var(--text-primary);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--border-color);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.content-preview {
    max-height: 400px;
    overflow-y: auto;
    padding: 16px;
    background: #f8fafc;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    line-height: 1.7;
    color: var(--text-secondary);
}

/* Links Tab */
.links-comparison {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.links-column h4 {
    font-size: 0.95rem;
    color: var(--text-primary);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--border-color);
}

.links-list {
    max-height: 300px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.link-item {
    display: block;
    padding: 8px 12px;
    background: #f8fafc;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    color: var(--primary-color);
    text-decoration: none;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    transition: var(--transition);
}

.link-item:hover {
    background: rgba(99, 102, 241, 0.1);
}

/* Error Section */
.error-section {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 48px;
    box-shadow: var(--shadow-md);
    text-align: center;
}

.error-content {
    max-width: 400px;
    margin: 0 auto;
}

.error-icon {
    font-size: 3rem;
    margin-bottom: 16px;
}

.error-section h3 {
    font-size: 1.5rem;
    color: var(--error-color);
    margin-bottom: 12px;
}

.error-section p {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

/* Footer */
footer {
    text-align: center;
    padding: 32px 20px;
    margin-top: auto;
    border-top: 1px solid var(--border-color);
}

footer p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

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

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

    header {
        padding: 24px 16px;
    }

    .logo-container {
        flex-direction: column;
        gap: 12px;
    }

    h1 {
        font-size: 1.5rem;
    }

    .subtitle {
        font-size: 0.95rem;
    }

    .input-section {
        padding: 20px;
    }

    .url-inputs {
        grid-template-columns: 1fr;
        gap: 16px;
    }

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

    .keywords-comparison,
    .links-comparison {
        grid-template-columns: 1fr;
    }

    .content-comparison {
        grid-template-columns: 1fr;
    }

    .tabs {
        flex-wrap: wrap;
    }

    .tab-btn {
        padding: 12px 16px;
        font-size: 0.9rem;
    }

    .score-circle {
        width: 140px;
        height: 140px;
    }

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

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

    .primary-btn {
        padding: 14px 24px;
        font-size: 1rem;
    }

    .input-group input {
        padding: 12px 14px;
    }

    .tab-content {
        padding: 16px;
    }
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: #f1f5f9;
    border-radius: 3px;
}

::-webkit-scrollbar-thumb {
    background: #cbd5e1;
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: #94a3b8;
}