/* ================================================
   papers.harsha.ai — Paper Browser Styles
   Extends the harsha.ai design system (style.css)
   Uses all existing CSS custom properties
   ================================================ */

/* --- Page Header --- */
.papers-header {
    text-align: center;
    margin-top: var(--space-xl);
    margin-bottom: var(--space-lg);
}

.papers-header h1 {
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.papers-intro {
    max-width: 700px;
    margin: 0 auto var(--space-md);
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--color-text-muted);
}

.papers-stats {
    font-size: 0.875rem;
    color: var(--color-text-light);
}

/* --- Controls --- */
.papers-controls {
    margin-bottom: var(--space-lg);
}

/* Search box */
.search-box {
    position: relative;
    margin-bottom: var(--space-md);
}

.search-box input {
    width: 100%;
    padding: var(--space-sm) var(--space-md);
    padding-right: 40px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    color: var(--color-text);
    font-size: 1rem;
    font-family: var(--font-sans);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.search-box input:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(49, 130, 206, 0.1);
}

.search-box input::placeholder {
    color: var(--color-text-light);
}

.search-clear {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--color-text-muted);
    font-size: 1.25rem;
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 4px;
    display: none;
}

.search-clear:hover {
    color: var(--color-text);
    background: var(--color-surface);
}

/* Topic filter buttons */
.topic-filters {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
    margin-bottom: var(--space-md);
}

.topic-btn {
    padding: 4px 14px;
    border-radius: 14px;
    border: 1px solid var(--color-border);
    background: var(--color-surface);
    color: var(--color-text-muted);
    font-size: 0.825rem;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.topic-btn:hover {
    border-color: var(--topic-color, var(--color-accent));
    color: var(--topic-color, var(--color-accent));
}

.topic-btn.active {
    background: var(--topic-color, var(--color-accent));
    color: #fff;
    border-color: var(--topic-color, var(--color-accent));
}

.topic-btn-clear {
    padding: 4px 14px;
    border-radius: 14px;
    border: 1px dashed var(--color-border);
    background: transparent;
    color: var(--color-text-light);
    font-size: 0.825rem;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.topic-btn-clear:hover {
    color: var(--color-text-muted);
    border-color: var(--color-text-light);
}

/* Date & sort row */
.controls-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-md);
    flex-wrap: wrap;
}

.date-filters {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    flex-wrap: wrap;
}

.date-filters label {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.date-filters input[type="date"] {
    padding: 4px 8px;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    background: var(--color-surface);
    color: var(--color-text);
    font-size: 0.875rem;
    font-family: var(--font-sans);
}

.filter-btn {
    padding: 4px 12px;
    border: 1px solid var(--color-accent);
    border-radius: 6px;
    background: transparent;
    color: var(--color-accent);
    font-size: 0.825rem;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.filter-btn:hover {
    background: var(--color-accent);
    color: #fff;
}

.sort-control {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.sort-control label {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.sort-control select {
    padding: 4px 8px;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    background: var(--color-surface);
    color: var(--color-text);
    font-size: 0.875rem;
    font-family: var(--font-sans);
    cursor: pointer;
}

/* Results info */
.results-info {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: var(--space-md);
}

/* --- Paper Cards --- */
.paper-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: var(--space-lg);
    margin-bottom: var(--space-md);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

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

.paper-title {
    margin: 0 0 var(--space-xs) 0;
    font-size: 1.1rem;
    font-weight: 500;
    line-height: 1.4;
}

.paper-title a {
    color: var(--color-accent);
    text-decoration: none;
}

.paper-title a:hover {
    text-decoration: underline;
}

.paper-meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-bottom: var(--space-sm);
}

.paper-meta span {
    display: inline-flex;
    align-items: center;
}

.paper-abstract {
    line-height: 1.6;
    color: var(--color-text);
    font-size: 0.95rem;
    margin-bottom: var(--space-sm);
}

.paper-abstract.collapsed {
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.abstract-toggle {
    background: none;
    border: none;
    color: var(--color-accent);
    font-size: 0.85rem;
    cursor: pointer;
    padding: 0;
    font-family: var(--font-sans);
}

.abstract-toggle:hover {
    text-decoration: underline;
}

/* Topic tags on cards */
.paper-topics {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
    margin-bottom: var(--space-sm);
}

.topic-tag {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 10px;
    font-size: 0.75rem;
    font-weight: 500;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    color: var(--topic-color, var(--color-text-muted));
    text-decoration: none;
    transition: all var(--transition-fast);
}

.topic-tag:hover {
    background: var(--topic-color, var(--color-accent));
    color: #fff;
    border-color: var(--topic-color, var(--color-accent));
    text-decoration: none;
}

/* Card footer */
.paper-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-sm);
    border-top: 1px dashed var(--color-border);
}

.paper-date {
    font-size: 0.8rem;
    color: var(--color-text-light);
}

.paper-links {
    display: flex;
    gap: var(--space-sm);
}

.paper-links a {
    font-size: 0.8rem;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 4px;
    transition: all var(--transition-fast);
}

.paper-links .summary-link {
    background: var(--color-accent);
    color: #fff;
    text-decoration: none;
}

.paper-links .summary-link:hover {
    opacity: 0.9;
    text-decoration: none;
}

.paper-links .pdf-link,
.paper-links .ss-link {
    color: var(--color-accent);
    text-decoration: none;
}

.paper-links .pdf-link:hover,
.paper-links .ss-link:hover {
    text-decoration: underline;
}

/* Score badge on cards */
.card-score {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    font-size: 0.75rem;
    font-weight: 700;
    color: #fff;
    flex-shrink: 0;
}

.card-score.score-high { background: #38a169; }
.card-score.score-mid { background: #d69e2e; }
.card-score.score-low { background: #a0aec0; }

/* --- Pagination --- */
.pagination {
    display: flex;
    justify-content: center;
    gap: var(--space-xs);
    margin: var(--space-xl) 0;
}

.pagination button {
    padding: 6px 12px;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    background: var(--color-surface);
    color: var(--color-text);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.pagination button:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

.pagination button.current {
    background: var(--color-accent);
    color: #fff;
    border-color: var(--color-accent);
}

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

/* Loading state */
.loading-spinner {
    text-align: center;
    padding: var(--space-xl);
    color: var(--color-text-muted);
}

/* Empty state */
.empty-state {
    text-align: center;
    padding: var(--space-xl);
    color: var(--color-text-muted);
}

.empty-state h3 {
    margin-bottom: var(--space-sm);
    color: var(--color-text);
}

/* ================================================
   Paper Detail Page
   ================================================ */

.paper-detail-page {
    margin-top: var(--space-lg);
    margin-bottom: var(--space-xl);
}

.back-link {
    display: inline-block;
    margin-bottom: var(--space-lg);
    font-size: 0.95rem;
    color: var(--color-accent);
    text-decoration: none;
}

.back-link:hover {
    text-decoration: underline;
}

.paper-detail {
    max-width: 800px;
    margin: 0 auto;
}

.paper-detail-title {
    font-size: clamp(1.5rem, 1.25rem + 1vw, 2rem);
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--space-md);
}

.paper-detail-title a {
    color: var(--color-text);
    text-decoration: none;
}

.paper-detail-title a:hover {
    color: var(--color-accent);
}

.paper-detail-meta {
    margin-bottom: var(--space-md);
}

.paper-authors-full {
    font-size: 1rem;
    color: var(--color-text-muted);
    line-height: 1.6;
    margin-bottom: var(--space-xs);
}

.paper-venue-info {
    font-size: 0.9rem;
    color: var(--color-text-light);
    margin-bottom: var(--space-xs);
}

.paper-detail-links {
    display: flex;
    gap: var(--space-md);
}

.detail-link {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-accent);
    text-decoration: none;
}

.detail-link:hover {
    text-decoration: underline;
}

/* Analysis sections */
.analysis-section {
    margin-bottom: var(--space-lg);
}

.analysis-section h2 {
    font-size: 1.25rem;
    font-weight: 600;
    font-style: normal;
    color: var(--color-text);
    margin-bottom: var(--space-sm);
    padding-bottom: var(--space-xs);
    border-bottom: 1px solid var(--color-border);
}

.analysis-section p {
    line-height: 1.7;
}

.analysis-section ul,
.analysis-section ol {
    padding-left: var(--space-lg);
    line-height: 1.7;
}

.analysis-section li {
    margin-bottom: var(--space-xs);
}

/* Thesis box */
.thesis-box {
    background: var(--color-surface);
    border-left: 4px solid var(--color-accent);
    padding: var(--space-md) var(--space-lg);
    border-radius: 0 8px 8px 0;
    font-size: 1.1rem;
    line-height: 1.6;
    font-style: italic;
    color: var(--color-text);
}

/* Breakthrough score */
.breakthrough-score {
    display: flex;
    align-items: flex-start;
    gap: var(--space-md);
}

.score-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 48px;
    height: 48px;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 700;
    color: #fff;
    flex-shrink: 0;
}

.score-badge.score-high { background: #38a169; }
.score-badge.score-mid { background: #d69e2e; }
.score-badge.score-low { background: #a0aec0; }

.score-justification {
    line-height: 1.6;
    color: var(--color-text-muted);
    padding-top: var(--space-xs);
}

/* Components grid */
.components-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-md);
}

.component-item {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    padding: var(--space-md);
}

.component-item strong {
    display: block;
    margin-bottom: var(--space-xs);
    color: var(--color-accent);
}

.component-item p {
    margin: 0;
    font-size: 0.95rem;
}

/* Results table */
.results-table-wrapper {
    overflow-x: auto;
}

.results-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.results-table th,
.results-table td {
    padding: var(--space-xs) var(--space-sm);
    text-align: left;
    border-bottom: 1px solid var(--color-border);
}

.results-table th {
    background: var(--color-surface);
    font-weight: 600;
    color: var(--color-text);
}

.results-table td {
    color: var(--color-text-muted);
}

.results-table tr:hover td {
    background: var(--color-surface);
}

/* Abstract section on detail page */
.abstract-section {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    padding: var(--space-lg);
}

.abstract-section h2 {
    border-bottom: none;
    padding-bottom: 0;
}

/* TL;DR text */
.tldr-text {
    font-style: italic;
    color: var(--color-text-muted);
}

/* No analysis note */
.no-analysis-note {
    font-style: italic;
    color: var(--color-text-light);
    margin-top: var(--space-md);
}

/* Generation info */
.generation-info {
    text-align: right;
    font-size: 0.8rem;
    color: var(--color-text-light);
    margin-top: var(--space-lg);
    padding-top: var(--space-sm);
    border-top: 1px solid var(--color-border);
}

/* --- Responsive --- */
@media (max-width: 768px) {
    .controls-row {
        flex-direction: column;
        align-items: stretch;
    }

    .date-filters {
        flex-wrap: wrap;
    }

    .sort-control {
        justify-content: flex-start;
    }

    .paper-footer {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--space-xs);
    }

    .breakthrough-score {
        flex-direction: column;
    }

    .paper-detail-title {
        font-size: 1.35rem;
    }

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