:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --success-color: #059669;
    --warning-color: #d97706;
    --danger-color: #dc2626;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-900: #111827;
    --border-radius: 8px;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 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);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--gray-900);
    background-color: var(--gray-100);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header */
header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 2rem 0;
    box-shadow: var(--shadow-lg);
}

header h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

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

/* Main Content */
main {
    padding: 2rem 0;
}

/* Search and Filters */
.search-filters {
    background: white;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
}

.search-box {
    margin-bottom: 1.5rem;
}

.search-box input {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    border: 2px solid var(--gray-300);
    border-radius: var(--border-radius);
    transition: border-color 0.2s;
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.filters {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
}

.filter-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.filter-group label {
    font-weight: 500;
    color: var(--gray-700);
    white-space: nowrap;
}

.filter-group select {
    padding: 0.5rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--border-radius);
    font-size: 0.875rem;
    cursor: pointer;
}

.filter-group input[type="text"] {
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--border-radius);
    font-size: 0.875rem;
    min-width: 180px;
}

.filter-group input[type="checkbox"] {
    cursor: pointer;
    width: 1rem;
    height: 1rem;
}

/* Statistics */
.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
}

.stat-card .number {
    font-size: 2rem;
    font-weight: bold;
    color: var(--primary-color);
}

.stat-card .label {
    color: var(--gray-600);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

/* Results */
.results {
    display: grid;
    gap: 1rem;
}

.call-card {
    background: white;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
    border-left: 4px solid var(--gray-300);
}

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

.call-card.rank-a-star {
    border-left-color: #dc2626;
}

.call-card.rank-q1 {
    border-left-color: #059669;
}

.call-card.rank-a {
    border-left-color: #d97706;
}

.call-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 1rem;
    gap: 1rem;
}

.call-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-900);
    flex: 1;
}

.call-title a {
    color: inherit;
    text-decoration: none;
}

.call-title a:hover {
    color: var(--primary-color);
}

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

.badge {
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    white-space: nowrap;
}

.badge.rank-a-star {
    background: #fee2e2;
    color: #991b1b;
}

.badge.rank-q1 {
    background: #d1fae5;
    color: #065f46;
}

.badge.rank-a {
    background: #fed7aa;
    color: #92400e;
}

.badge.rank-b,
.badge.rank-q2 {
    background: #dbeafe;
    color: #1e40af;
}

.badge.conference {
    background: var(--gray-200);
    color: var(--gray-700);
}

.badge.journal {
    background: #e0e7ff;
    color: #3730a3;
}

.badge.status-open {
    background: #d1fae5;
    color: #065f46;
}

.badge.status-upcoming {
    background: #fef3c7;
    color: #92400e;
}

.badge.status-closed {
    background: var(--gray-200);
    color: var(--gray-600);
}

.badge.urgent {
    background: #fee2e2;
    color: #991b1b;
    animation: pulse 2s infinite;
}

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

.call-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    margin-bottom: 1rem;
    color: var(--gray-600);
    font-size: 0.875rem;
}

.call-meta-item {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.call-meta-item strong {
    color: var(--gray-900);
}

.call-topics {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.topic-tag {
    padding: 0.25rem 0.5rem;
    background: var(--gray-100);
    border-radius: var(--border-radius);
    font-size: 0.75rem;
    color: var(--gray-700);
}

.call-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    align-items: center;
    margin-bottom: 0.75rem;
}

.action-button {
    border: 1px solid var(--gray-300);
    background: white;
    padding: 0.5rem 0.75rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-weight: 600;
    font-size: 0.85rem;
    transition: background 0.2s, border-color 0.2s, color 0.2s;
}

.action-button:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.action-button.secondary {
    background: var(--gray-100);
}

.compare-toggle {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    font-weight: 600;
    color: var(--gray-700);
}

.call-notes {
    color: var(--gray-600);
    font-size: 0.875rem;
    font-style: italic;
    margin-top: 0.5rem;
}

.priority-score {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border-radius: var(--border-radius);
    font-size: 0.75rem;
    font-weight: 600;
}

.no-results {
    background: white;
    padding: 3rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
    color: var(--gray-600);
}

.loading {
    text-align: center;
    padding: 3rem;
    color: var(--gray-600);
    font-size: 1.125rem;
}

.compare-panel {
    background: white;
    padding: 1rem 1.25rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 1.5rem;
}

.compare-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 0.75rem;
}

.compare-subtitle {
    color: var(--gray-600);
    font-size: 0.9rem;
}

.compare-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 0.75rem;
}

.compare-card {
    border: 1px solid var(--gray-200);
    border-radius: var(--border-radius);
    padding: 0.75rem;
    background: var(--gray-100);
}

.compare-title {
    font-weight: 700;
    margin-bottom: 0.35rem;
}

.compare-line {
    font-size: 0.9rem;
    color: var(--gray-700);
    margin-bottom: 0.2rem;
}

.hidden {
    display: none;
}

/* Footer */
footer {
    background: white;
    padding: 2rem 0;
    margin-top: 3rem;
    border-top: 1px solid var(--gray-200);
    text-align: center;
    color: var(--gray-600);
    font-size: 0.875rem;
}

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

footer a:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
    header h1 {
        font-size: 1.5rem;
    }

    .subtitle {
        font-size: 1rem;
    }

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

    .filter-group {
        width: 100%;
    }

    .filter-group select {
        flex: 1;
    }

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

    .badges {
        width: 100%;
    }

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