/* CSS Variables */
:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #6b7280;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --background-color: #f9fafb;
    --surface-color: #ffffff;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --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 -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --transition: all 0.2s ease;
}

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

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

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

/* App Container */
.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #7c3aed 100%);
    color: white;
    padding: 2rem 1.5rem;
    text-align: center;
}

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

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

.header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    margin: 0;
}

.tagline {
    font-size: 1rem;
    opacity: 0.9;
    margin-top: 0.5rem;
}

/* Main Content */
.main-content {
    flex: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    width: 100%;
}

/* Upload Section */
.upload-section {
    margin-bottom: 2rem;
}

.upload-area {
    background: var(--surface-color);
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-lg);
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
}

.upload-area:hover,
.upload-area.drag-over {
    border-color: var(--primary-color);
    background: rgba(79, 70, 229, 0.05);
}

.upload-icon {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.upload-text {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

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

.upload-formats {
    color: var(--text-secondary);
    font-size: 0.75rem;
    margin-top: 1rem;
}

/* Text Input Section */
.text-input-section {
    margin-top: 1.5rem;
}

.or-divider {
    text-align: center;
    color: var(--text-secondary);
    margin: 1.5rem 0;
    position: relative;
}

.or-divider::before,
.or-divider::after {
    content: '';
    position: absolute;
    top: 50%;
    width: calc(50% - 2rem);
    height: 1px;
    background: var(--border-color);
}

.or-divider::before {
    left: 0;
}

.or-divider::after {
    right: 0;
}

.or-divider span {
    background: var(--background-color);
    padding: 0 1rem;
}

textarea {
    width: 100%;
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 1rem;
    resize: vertical;
    transition: var(--transition);
}

textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.625rem 1.25rem;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: var(--transition);
    gap: 0.5rem;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    margin-top: 1rem;
}

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

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

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

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

.btn-danger:hover {
    background: #dc2626;
}

/* Settings Section */
.settings-section {
    background: var(--surface-color);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-sm);
}

.settings-section h2 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
}

.setting-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

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

.setting-item input[type="number"] {
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
}

.setting-item input[type="checkbox"] {
    width: 1.25rem;
    height: 1.25rem;
    cursor: pointer;
}

/* Results Section */
.results-section {
    background: var(--surface-color);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
}

.results-header {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.results-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
}

.results-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

/* Stats Container */
.stats-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.stat-card {
    background: var(--background-color);
    border-radius: var(--radius-md);
    padding: 1rem;
    text-align: center;
}

.stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

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

/* View Toggle */
.view-toggle {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    padding: 0.25rem;
    background: var(--background-color);
    border-radius: var(--radius-md);
    width: fit-content;
}

.view-btn {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-secondary);
}

.view-btn:hover {
    color: var(--text-primary);
}

.view-btn.active {
    background: var(--surface-color);
    color: var(--primary-color);
    box-shadow: var(--shadow-sm);
}

/* Table View */
.table-container {
    overflow-x: auto;
}

.keywords-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
}

.keywords-table th,
.keywords-table td {
    padding: 0.75rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.keywords-table th {
    font-weight: 600;
    color: var(--text-secondary);
    background: var(--background-color);
    position: sticky;
    top: 0;
}

.keywords-table tbody tr:hover {
    background: var(--background-color);
}

.relevance-bar {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.relevance-fill {
    height: 8px;
    background: linear-gradient(90deg, var(--primary-color), var(--success-color));
    border-radius: 4px;
    transition: width 0.3s ease;
}

/* Word Cloud View */
.word-cloud {
    min-height: 300px;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    padding: 2rem;
}

.cloud-word {
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
    cursor: default;
    transition: var(--transition);
}

.cloud-word:hover {
    transform: scale(1.1);
}

/* Chart View */
.chart-container {
    padding: 1rem 0;
}

.chart-bar {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 0.75rem;
}

.chart-label {
    width: 120px;
    font-size: 0.875rem;
    text-align: right;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.chart-bar-container {
    flex: 1;
    height: 24px;
    background: var(--background-color);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.chart-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), #7c3aed);
    border-radius: var(--radius-sm);
    transition: width 0.5s ease;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-right: 0.5rem;
}

.chart-value {
    font-size: 0.75rem;
    color: white;
    font-weight: 500;
}

/* Clear Section */
.clear-section {
    margin-top: 1.5rem;
    text-align: center;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    inset: 0;
    background: rgba(255, 255, 255, 0.9);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.loading-overlay[hidden] {
    display: none;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

.loading-overlay p {
    margin-top: 1rem;
    color: var(--text-secondary);
}

/* Footer */
.footer {
    background: var(--text-primary);
    color: white;
    padding: 1.5rem;
    text-align: center;
    margin-top: auto;
}

.footer a {
    color: #a5b4fc;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.footer a:hover {
    color: white;
    text-decoration: underline;
}

/* Notification Toast */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    background: var(--text-primary);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    z-index: 1001;
    animation: slideUp 0.3s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(1rem);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .header {
        padding: 1.5rem 1rem;
    }

    .header h1 {
        font-size: 1.5rem;
    }

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

    .main-content {
        padding: 1rem;
    }

    .upload-area {
        padding: 2rem 1rem;
    }

    .results-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .results-actions {
        width: 100%;
    }

    .results-actions .btn {
        flex: 1;
        min-width: calc(50% - 0.25rem);
    }

    .view-toggle {
        width: 100%;
        justify-content: space-between;
    }

    .view-btn {
        flex: 1;
        text-align: center;
    }

    .chart-label {
        width: 80px;
        font-size: 0.75rem;
    }

    .keywords-table th,
    .keywords-table td {
        padding: 0.5rem;
    }

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

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

    .tagline {
        font-size: 0.875rem;
    }

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

    .results-actions .btn {
        font-size: 0.75rem;
        padding: 0.5rem 0.75rem;
    }

    .stat-value {
        font-size: 1.25rem;
    }
}