/* Athena - Dark Theme with Gold Accents */

:root {
    /* Background layers */
    --bg-primary: #0a0c10;
    --bg-secondary: #12161d;
    --bg-tertiary: #1a1f2a;
    --bg-hover: #232936;

    /* Text */
    --text-primary: #e8edf5;
    --text-secondary: #8b95a5;
    --text-muted: #5a6270;

    /* Athena Gold */
    --gold: #d4a84b;
    --gold-bright: #f0c45a;
    --gold-dim: #a07830;
    --gold-glow: rgba(212, 168, 75, 0.15);

    /* Functional */
    --border: #2a3140;
    --border-light: #3a4458;
    --success: #4ade80;
    --warning: #fbbf24;
    --error: #f87171;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.6);
    --shadow-gold: 0 0 20px rgba(212, 168, 75, 0.1);

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* Sizing */
    --header-height: 64px;
    --sidebar-width: 280px;
}

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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

a {
    color: var(--gold);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: var(--gold-bright);
}

/* Header */
.header {
    height: var(--header-height);
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    padding: 0 1.5rem;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-primary);
    font-weight: 600;
    font-size: 1.25rem;
}

.header-brand:hover {
    color: var(--gold);
}

.logo {
    width: 32px;
    height: 32px;
    color: var(--gold);
}

.logo svg {
    width: 100%;
    height: 100%;
}

.brand-text {
    background: linear-gradient(135deg, var(--gold) 0%, var(--gold-bright) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-nav {
    display: flex;
    gap: 0.5rem;
    margin-left: 3rem;
}

.nav-link {
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-weight: 500;
    transition: all 0.2s;
}

.nav-link:hover {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.nav-link.active {
    color: var(--gold);
    background: var(--gold-glow);
}

.header-stats {
    margin-left: auto;
    display: flex;
    align-items: baseline;
    gap: 0.35rem;
}

.stat-number {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--gold);
}

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

/* Main */
.main {
    flex: 1;
    padding: 1.5rem;
}

/* Footer */
.footer {
    padding: 1rem 1.5rem;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
    border-top: 1px solid var(--border);
}

/* Search Layout */
.search-layout {
    display: grid;
    grid-template-columns: var(--sidebar-width) 1fr;
    gap: 2rem;
    max-width: 1600px;
    margin: 0 auto;
}

/* Sidebar */
.sidebar {
    position: sticky;
    top: calc(var(--header-height) + 1.5rem);
    height: fit-content;
}

.filters {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.filter-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.filter-label {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
}

.filter-select,
.filter-input {
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.625rem 0.875rem;
    color: var(--text-primary);
    font-size: 0.9rem;
    font-family: inherit;
    transition: all 0.2s;
}

.filter-select:hover,
.filter-input:hover {
    border-color: var(--border-light);
}

.filter-select:focus,
.filter-input:focus {
    outline: none;
    border-color: var(--gold);
    box-shadow: 0 0 0 3px var(--gold-glow);
}

.year-inputs {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.year-inputs .filter-input {
    flex: 1;
    text-align: center;
}

.year-separator {
    color: var(--text-muted);
}

/* Search Box */
.search-box {
    position: relative;
    margin-bottom: 1.5rem;
}

.search-icon {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    width: 20px;
    height: 20px;
    color: var(--text-muted);
    pointer-events: none;
}

.search-input {
    width: 100%;
    background: var(--bg-secondary);
    border: 2px solid var(--border);
    border-radius: 12px;
    padding: 1rem 1rem 1rem 3rem;
    color: var(--text-primary);
    font-size: 1.1rem;
    font-family: inherit;
    transition: all 0.2s;
}

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

.search-input:hover {
    border-color: var(--border-light);
}

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

.search-indicator {
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    opacity: 0;
    transition: opacity 0.2s;
}

.search-indicator.htmx-request {
    opacity: 1;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border);
    border-top-color: var(--gold);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* Results */
.results-header {
    display: flex;
    align-items: baseline;
    gap: 0.5rem;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border);
}

.results-count {
    font-weight: 600;
    color: var(--text-primary);
}

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

.results-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

/* Paper Card */
.paper-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.25rem;
    cursor: pointer;
    transition: all 0.2s;
}

.paper-card:hover {
    border-color: var(--gold-dim);
    box-shadow: var(--shadow-gold);
    transform: translateY(-1px);
}

.paper-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
}

.paper-year,
.paper-journal,
.paper-type {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
}

.paper-year {
    color: var(--gold);
}

.paper-type.supplement {
    background: var(--gold-glow);
    color: var(--gold);
}

.paper-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.paper-authors {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
}

.paper-snippet,
.paper-abstract {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.5;
}

.paper-snippet mark {
    background: var(--gold-glow);
    color: var(--gold);
    padding: 0.1em 0.2em;
    border-radius: 2px;
}

.paper-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1rem;
    padding-top: 0.75rem;
    border-top: 1px solid var(--border);
}

.paper-topic {
    font-size: 0.8rem;
    color: var(--text-muted);
    background: var(--bg-tertiary);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
}

.paper-doi {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-family: monospace;
}

/* No Results */
.no-results {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-muted);
}

.no-results-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 1rem;
    color: var(--border-light);
}

.no-results-icon svg {
    width: 100%;
    height: 100%;
}

.no-results-hint {
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
}

.page-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-secondary);
    font-weight: 500;
    transition: all 0.2s;
}

.page-btn:hover {
    border-color: var(--gold);
    color: var(--gold);
}

.page-btn svg {
    width: 16px;
    height: 16px;
}

.page-info {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Browse Layout */
.browse-layout {
    max-width: 1200px;
    margin: 0 auto;
}

.browse-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.browse-title {
    font-size: 1.5rem;
    font-weight: 600;
}

.browse-tabs {
    display: flex;
    gap: 0.5rem;
}

.browse-tab {
    padding: 0.5rem 1rem;
    border-radius: 8px;
    color: var(--text-secondary);
    font-weight: 500;
    transition: all 0.2s;
}

.browse-tab:hover {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.browse-tab.active {
    color: var(--gold);
    background: var(--gold-glow);
}

.browse-groups {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.browse-group {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    overflow: hidden;
}

.group-title {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.25rem;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--border);
}

.group-name {
    font-size: 1rem;
    font-weight: 600;
}

.group-count {
    font-size: 0.875rem;
    color: var(--gold);
    background: var(--gold-glow);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
}

.group-papers {
    display: flex;
    flex-direction: column;
}

.browse-paper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.875rem 1.25rem;
    color: var(--text-primary);
    border-bottom: 1px solid var(--border);
    transition: background 0.2s;
}

.browse-paper:last-child {
    border-bottom: none;
}

.browse-paper:hover {
    background: var(--bg-hover);
}

.browse-paper-title {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.browse-paper-year,
.browse-paper-author {
    color: var(--text-muted);
    font-size: 0.875rem;
    margin-left: 1rem;
}

/* Paper Detail */
.paper-layout {
    max-width: 900px;
    margin: 0 auto;
}

.paper-header {
    margin-bottom: 1.5rem;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.back-link:hover {
    color: var(--gold);
}

.back-link svg {
    width: 18px;
    height: 18px;
}

.paper-detail {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 2rem;
}

.paper-detail-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.meta-item {
    font-size: 0.8rem;
    font-weight: 600;
    padding: 0.375rem 0.75rem;
    border-radius: 6px;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
}

.meta-item.year {
    color: var(--gold);
    background: var(--gold-glow);
}

.meta-item.journal {
    color: var(--text-primary);
}

.meta-item.supplement {
    color: var(--warning);
}

.paper-detail-title {
    font-size: 1.75rem;
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 1rem;
}

.paper-detail-authors {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.paper-detail-doi {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

.doi-label {
    font-weight: 600;
    margin-right: 0.25rem;
}

.paper-detail-abstract {
    margin-bottom: 1.5rem;
}

.paper-detail-abstract h2,
.paper-detail-keywords h2,
.paper-detail-info h2 {
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
}

.paper-detail-abstract p {
    color: var(--text-secondary);
    line-height: 1.7;
}

.paper-detail-keywords {
    margin-bottom: 1.5rem;
}

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

.keyword {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: 0.375rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
}

.paper-actions {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all 0.2s;
}

.btn svg {
    width: 18px;
    height: 18px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--gold) 0%, var(--gold-dim) 100%);
    color: #000;
}

.btn-primary:hover {
    color: #000;
    box-shadow: var(--shadow-gold), 0 4px 12px rgba(212, 168, 75, 0.3);
    transform: translateY(-1px);
}

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

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

.paper-detail-info {
    background: var(--bg-tertiary);
    border-radius: 8px;
    padding: 1.25rem;
}

.info-list {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 0.5rem 1.5rem;
}

.info-list dt {
    color: var(--text-muted);
    font-size: 0.875rem;
}

.info-list dd {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.quality-good {
    color: var(--success);
}

.quality-partial {
    color: var(--warning);
}

.quality-failed {
    color: var(--error);
}

/* Responsive */
@media (max-width: 1024px) {
    .search-layout {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: static;
    }

    .filters {
        flex-direction: row;
        flex-wrap: wrap;
    }

    .filter-group {
        flex: 1;
        min-width: 150px;
    }
}

@media (max-width: 768px) {
    .header {
        padding: 0 1rem;
    }

    .header-nav {
        margin-left: 1.5rem;
    }

    .main {
        padding: 1rem;
    }

    .paper-detail {
        padding: 1.25rem;
    }

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

    .paper-actions {
        flex-direction: column;
    }

    .browse-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
}

@media (max-width: 480px) {
    .header-stats {
        display: none;
    }

    .filters {
        flex-direction: column;
    }

    .filter-group {
        min-width: 100%;
    }
}