/* ============================================================
   AI Research Summarizer - Main Stylesheet
   ============================================================ */

/* ---- CSS Variables ---- */
:root {
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-primary-light: #dbeafe;
    --color-secondary: #7c3aed;
    --color-secondary-light: #ede9fe;
    --color-success: #059669;
    --color-success-light: #d1fae5;
    --color-warning: #d97706;
    --color-warning-light: #fef3c7;
    --color-danger: #dc2626;
    --color-danger-light: #fee2e2;
    --color-info: #0891b2;
    --color-info-light: #cffafe;
    --color-bg: #f8fafc;
    --color-surface: #ffffff;
    --color-text: #1e293b;
    --color-text-secondary: #64748b;
    --color-text-muted: #94a3b8;
    --color-border: #e2e8f0;
    --color-border-dark: #cbd5e1;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.12);
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    --transition: 0.2s ease;
}

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

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

body {
    font-family: var(--font-sans);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition);
}

a:hover {
    color: var(--color-primary-dark);
}

/* ---- Header ---- */
.app-header {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: white;
    padding: 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-md);
}

.header-content {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0.75rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-size: 1.4rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: white;
}

.logo-icon {
    font-size: 1.6rem;
}

.main-nav {
    display: flex;
    gap: 0.5rem;
}

.nav-link {
    color: rgba(255, 255, 255, 0.85);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    font-weight: 500;
    font-size: 0.9rem;
    transition: all var(--transition);
}

.nav-link:hover,
.nav-link.active {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

/* ---- Main Content ---- */
.main-content {
    max-width: 1280px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    min-height: calc(100vh - 120px);
}

/* ---- Footer ---- */
.app-footer {
    background: var(--color-surface);
    border-top: 1px solid var(--color-border);
    padding: 1rem;
    text-align: center;
    color: var(--color-text-muted);
    font-size: 0.85rem;
}

/* ---- Card Component ---- */
.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    transition: box-shadow var(--transition);
}

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

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--color-border);
}

.card-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
}

.card-subtitle {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    margin-top: 0.25rem;
}

/* ---- Dashboard ---- */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.stat-card .stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary);
}

.stat-card .stat-label {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    margin-top: 0.25rem;
}

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

.session-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.25rem;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition);
}

.session-item:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
}

.session-item .session-title {
    font-weight: 600;
    font-size: 1rem;
}

.session-item .session-meta {
    font-size: 0.8rem;
    color: var(--color-text-muted);
}

/* ---- Forms ---- */
.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 0.4rem;
    color: var(--color-text);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.65rem 0.85rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-family: var(--font-sans);
    transition: border-color var(--transition), box-shadow var(--transition);
    background: var(--color-surface);
    color: var(--color-text);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-light);
}

.form-group textarea {
    min-height: 120px;
    resize: vertical;
}

/* ---- Buttons ---- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.6rem 1.2rem;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition);
    font-family: var(--font-sans);
}

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

.btn-primary:hover {
    background: var(--color-primary-dark);
    box-shadow: var(--shadow-sm);
}

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

.btn-secondary:hover {
    background: #6d28d9;
}

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

.btn-success:hover {
    background: #047857;
}

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

.btn-outline {
    background: transparent;
    border: 1px solid var(--color-border-dark);
    color: var(--color-text);
}

.btn-outline:hover {
    background: var(--color-bg);
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.btn-sm {
    padding: 0.35rem 0.75rem;
    font-size: 0.8rem;
}

.btn-lg {
    padding: 0.8rem 1.8rem;
    font-size: 1rem;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* ---- Badges ---- */
.badge {
    display: inline-block;
    padding: 0.2rem 0.6rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-primary { background: var(--color-primary-light); color: var(--color-primary); }
.badge-success { background: var(--color-success-light); color: var(--color-success); }
.badge-warning { background: var(--color-warning-light); color: var(--color-warning); }
.badge-danger { background: var(--color-danger-light); color: var(--color-danger); }
.badge-info { background: var(--color-info-light); color: var(--color-info); }

/* ---- Tabs ---- */
.tab-bar {
    display: flex;
    border-bottom: 2px solid var(--color-border);
    margin-bottom: 1.5rem;
    gap: 0;
}

.tab-btn {
    padding: 0.65rem 1.25rem;
    border: none;
    background: transparent;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-text-secondary);
    cursor: pointer;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;
    transition: all var(--transition);
    font-family: var(--font-sans);
}

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

.tab-btn.active {
    color: var(--color-primary);
    border-bottom-color: var(--color-primary);
}

.tab-content {
    display: none;
}

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

/* ---- Summary Section ---- */
.summary-block {
    background: var(--color-primary-light);
    border-left: 4px solid var(--color-primary);
    padding: 1.25rem;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin-bottom: 1rem;
    line-height: 1.7;
}

.summary-block .confidence {
    margin-top: 0.5rem;
    font-size: 0.8rem;
    color: var(--color-text-secondary);
}

/* ---- Theme Tags ---- */
.theme-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.theme-tag {
    background: var(--color-secondary-light);
    color: var(--color-secondary);
    padding: 0.4rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.3rem;
}

.theme-tag .theme-freq {
    background: var(--color-secondary);
    color: white;
    border-radius: 50%;
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
}

/* ---- Action Items & Risks ---- */
.item-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.item-row {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
}

.item-row.action { border-left: 3px solid var(--color-info); }
.item-row.risk { border-left: 3px solid var(--color-danger); }

.item-priority {
    flex-shrink: 0;
}

.item-text {
    font-size: 0.9rem;
    line-height: 1.5;
}

/* ---- Comparison Matrix Table ---- */
.matrix-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.88rem;
}

.matrix-table th,
.matrix-table td {
    padding: 0.65rem 0.85rem;
    border: 1px solid var(--color-border);
    text-align: left;
}

.matrix-table th {
    background: var(--color-bg);
    font-weight: 600;
    color: var(--color-text);
    white-space: nowrap;
}

.matrix-table td {
    color: var(--color-text-secondary);
}

.matrix-table tr:hover td {
    background: var(--color-primary-light);
}

/* ---- Export Preview ---- */
.export-preview {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 2rem;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    line-height: 1.7;
    white-space: pre-wrap;
    max-height: 600px;
    overflow-y: auto;
}

/* ---- Toast Notifications ---- */
#toast-container {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.toast {
    padding: 0.75rem 1.25rem;
    border-radius: var(--radius-sm);
    color: white;
    font-size: 0.9rem;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    animation: slideIn 0.3s ease;
    max-width: 400px;
}

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

@keyframes slideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

/* ---- Loading Spinner ---- */
.spinner {
    display: inline-block;
    width: 24px;
    height: 24px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.loading-overlay {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    padding: 3rem;
    color: var(--color-text-secondary);
}

/* ---- Empty State ---- */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--color-text-muted);
}

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

.empty-state .empty-message {
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

/* ---- Source Cards ---- */
.source-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 1rem 1.25rem;
    margin-bottom: 0.75rem;
}

.source-card .source-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 0.5rem;
}

.source-card .source-title {
    font-weight: 600;
    font-size: 0.95rem;
}

.source-card .source-preview {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.5;
    max-height: 60px;
    overflow: hidden;
}

/* ---- Responsive ---- */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 0.5rem;
    }

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

    .tab-bar {
        overflow-x: auto;
    }

    .matrix-table {
        display: block;
        overflow-x: auto;
    }
}