:root {
    --primary: #1a365d;
    --primary-light: #2a4a7f;
    --accent: #3182ce;
    --accent-light: #63b3ed;
    --bg: #f7fafc;
    --card-bg: #ffffff;
    --text: #2d3748;
    --text-light: #718096;
    --border: #e2e8f0;
    --tag-conf: #fef3c7; --tag-conf-text: #92400e;
    --tag-bench: #dbeafe; --tag-bench-text: #1e40af;
    --tag-dialog: #d1fae5; --tag-dialog-text: #065f46;
    --tag-rag: #ede9fe; --tag-rag-text: #5b21b6;
    --tag-knowledge: #e0e7ff; --tag-knowledge-text: #3730a3;
    --tag-safety: #fee2e2; --tag-safety-text: #991b1b;
    --tag-unlearning: #fce7f3; --tag-unlearning-text: #9d174d;
    --tag-ir: #ccfbf1; --tag-ir-text: #134e4a;
    --tag-multi: #c7d2fe; --tag-multi-text: #4338ca;
    --tag-detect: #fef9c3; --tag-detect-text: #854d0e;
    --tag-kg: #f3e8ff; --tag-kg-text: #6b21a8;
}

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

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Hero */
.hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 50%, var(--accent) 100%);
    color: white;
    padding: 60px 20px;
    text-align: center;
}
.hero h1 { font-size: 2.5rem; font-weight: 800; margin-bottom: 12px; }
.hero p { font-size: 1.1rem; opacity: 0.9; max-width: 600px; margin: 0 auto; }
.hero a { color: var(--accent-light); text-decoration: underline; }

.container { max-width: 1100px; margin: 0 auto; padding: 40px 20px; }

/* Filter */
.filter-bar { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 32px; align-items: center; }
.filter-bar label { font-weight: 600; margin-right: 8px; color: var(--text-light); font-size: 0.9rem; }
.filter-btn {
    padding: 6px 16px; border: 1px solid var(--border); border-radius: 20px;
    background: white; cursor: pointer; font-size: 0.85rem; transition: all 0.2s; color: var(--text);
}
.filter-btn:hover { border-color: var(--accent); color: var(--accent); }
.filter-btn.active { background: var(--accent); color: white; border-color: var(--accent); }

/* Stats */
.stats-bar { display: flex; gap: 24px; margin-bottom: 32px; flex-wrap: wrap; }
.stat-item {
    text-align: center; padding: 16px 24px; background: white;
    border-radius: 10px; border: 1px solid var(--border); min-width: 120px;
}
.stat-num { font-size: 1.8rem; font-weight: 800; color: var(--accent); }
.stat-label { font-size: 0.8rem; color: var(--text-light); font-weight: 500; }

/* Year sections */
.year-section { margin-bottom: 48px; }
.year-heading {
    font-size: 1.6rem; font-weight: 700; color: var(--primary);
    margin-bottom: 20px; padding-bottom: 8px; border-bottom: 3px solid var(--accent); display: inline-block;
}

/* Paper cards (index) */
.paper-card {
    background: var(--card-bg); border: 1px solid var(--border); border-radius: 12px;
    padding: 24px; margin-bottom: 16px; transition: box-shadow 0.2s, transform 0.15s;
}
.paper-card:hover { box-shadow: 0 4px 20px rgba(0,0,0,0.08); transform: translateY(-1px); }
.paper-card a.card-link {
    text-decoration: none; color: inherit; display: block;
}
.paper-header { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; }
.paper-title { font-size: 1.15rem; font-weight: 700; color: var(--primary); margin-bottom: 8px; }
.paper-authors { font-size: 0.9rem; color: var(--text-light); margin-bottom: 10px; }
.paper-venue {
    display: inline-block; font-size: 0.8rem; font-weight: 600; padding: 3px 10px;
    border-radius: 4px; background: var(--primary); color: white; white-space: nowrap; flex-shrink: 0;
}
.paper-venue.findings { background: var(--primary-light); }
.paper-venue.workshop { background: #6b7280; }
.paper-venue.preprint { background: #9ca3af; }

.paper-tags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 8px; }
.tag { font-size: 0.75rem; padding: 2px 10px; border-radius: 12px; font-weight: 500; }
.tag-confidence { background: #fef3c7; color: #92400e; }
.tag-benchmark { background: #dbeafe; color: #1e40af; }
.tag-dialogue { background: #d1fae5; color: #065f46; }
.tag-rag { background: #ede9fe; color: #5b21b6; }
.tag-knowledge { background: #e0e7ff; color: #3730a3; }
.tag-safety { background: #fee2e2; color: #991b1b; }
.tag-unlearning { background: #fce7f3; color: #9d174d; }
.tag-ir { background: #ccfbf1; color: #134e4a; }
.tag-multimodal { background: #c7d2fe; color: #4338ca; }
.tag-detection { background: #fef9c3; color: #854d0e; }
.tag-kg { background: #f3e8ff; color: #6b21a8; }
.tag-repr { background: #bfdbfe; color: #1e3a8a; }
.tag-parsing { background: #a7f3d0; color: #064e3b; }
.tag-reasoning { background: #fed7aa; color: #9a3412; }
.tag-domain { background: #99f6e4; color: #115e59; }
.tag-icl { background: #fbcfe8; color: #831843; }
.tag-efficiency { background: #ddd6fe; color: #5b21b6; }
.tag-multilingual { background: #cffafe; color: #155e75; }
.tag-abstention { background: #fecdd3; color: #9f1239; }

.paper-oneliner { font-size: 0.9rem; color: var(--text-light); margin-top: 10px; }

/* Paper detail page */
.back-link {
    display: inline-flex; align-items: center; gap: 6px; font-size: 0.9rem;
    color: var(--accent); margin-bottom: 24px; font-weight: 600;
}
.detail-hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: white; padding: 48px 20px;
}
.detail-hero .container { max-width: 900px; }
.detail-hero h1 { font-size: 1.8rem; font-weight: 800; margin-bottom: 16px; line-height: 1.3; }
.detail-hero .meta { opacity: 0.9; font-size: 0.95rem; }
.detail-hero .meta .venue-badge {
    display: inline-block; background: rgba(255,255,255,0.2); padding: 4px 14px;
    border-radius: 6px; font-weight: 600; margin-right: 12px;
}
.detail-hero .authors { margin-top: 12px; opacity: 0.85; font-size: 0.95rem; }

.detail-content { max-width: 900px; margin: 0 auto; padding: 40px 20px; }

.section { margin-bottom: 32px; }
.section h2 {
    font-size: 1.1rem; font-weight: 700; color: var(--accent);
    text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 12px;
    padding-bottom: 8px; border-bottom: 2px solid var(--border);
}
.section p { font-size: 1rem; line-height: 1.8; }

.key-points { list-style: none; padding: 0; }
.key-points li {
    padding: 8px 0 8px 24px; position: relative; font-size: 0.95rem; line-height: 1.7;
}
.key-points li::before {
    content: ">"; position: absolute; left: 0; color: var(--accent); font-weight: 700;
}

.highlight-box {
    background: #edf2f7; border-left: 4px solid var(--accent);
    padding: 16px 20px; border-radius: 0 8px 8px 0; margin: 16px 0;
}
.highlight-box p { font-size: 0.95rem; }

.links-section { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 16px; }
.paper-link {
    display: inline-flex; align-items: center; gap: 6px; font-size: 0.9rem;
    color: var(--accent); font-weight: 600; padding: 8px 20px;
    border: 2px solid var(--accent); border-radius: 8px; transition: all 0.2s;
}
.paper-link:hover { background: var(--accent); color: white; text-decoration: none; }

.nav-papers {
    display: flex; justify-content: space-between; margin-top: 48px;
    padding-top: 24px; border-top: 1px solid var(--border);
}
.nav-papers a {
    font-size: 0.9rem; color: var(--accent); font-weight: 600;
    padding: 8px 16px; border: 1px solid var(--border); border-radius: 8px;
}
.nav-papers a:hover { border-color: var(--accent); text-decoration: none; }

/* Language toggle */
.lang-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    display: flex;
    gap: 4px;
    background: rgba(255,255,255,0.15);
    border-radius: 6px;
    padding: 3px;
}
.lang-toggle a {
    padding: 4px 12px;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 600;
    color: rgba(255,255,255,0.7);
    text-decoration: none;
    transition: all 0.2s;
}
.lang-toggle a.active {
    background: rgba(255,255,255,0.25);
    color: white;
}
.lang-toggle a:hover { color: white; text-decoration: none; }
.hero, .detail-hero { position: relative; }

/* Figures */
.paper-figure {
    margin: 24px 0;
    background: white;
    border: 1px solid var(--border);
    border-radius: 10px;
    overflow: hidden;
}
.paper-figure img {
    width: 100%;
    display: block;
}
.paper-figure figcaption {
    padding: 12px 16px;
    font-size: 0.88rem;
    color: var(--text-light);
    line-height: 1.6;
    border-top: 1px solid var(--border);
    background: #f9fafb;
}
.paper-figure figcaption strong {
    color: var(--primary);
}
.figures-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin: 24px 0;
}
.figures-row .paper-figure { margin: 0; }

/* Results table */
.results-table {
    width: 100%;
    border-collapse: collapse;
    margin: 16px 0;
    font-size: 0.9rem;
    background: white;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border);
}
.results-table thead { background: var(--primary); color: white; }
.results-table th {
    padding: 10px 14px;
    text-align: left;
    font-weight: 600;
    font-size: 0.85rem;
}
.results-table td {
    padding: 10px 14px;
    border-top: 1px solid var(--border);
}
.results-table tbody tr:hover { background: #f7fafc; }
.results-table .highlight-cell { font-weight: 700; color: var(--accent); }

/* Method diagram */
.method-steps {
    display: flex;
    gap: 0;
    margin: 20px 0;
    flex-wrap: wrap;
}
.method-step {
    flex: 1;
    min-width: 180px;
    padding: 16px;
    background: white;
    border: 1px solid var(--border);
    position: relative;
    text-align: center;
}
.method-step:not(:last-child)::after {
    content: "\2192";
    position: absolute;
    right: -14px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.4rem;
    color: var(--accent);
    z-index: 1;
}
.method-step .step-num {
    display: inline-block;
    width: 28px; height: 28px;
    line-height: 28px;
    border-radius: 50%;
    background: var(--accent);
    color: white;
    font-weight: 700;
    font-size: 0.85rem;
    margin-bottom: 8px;
}
.method-step .step-title {
    font-weight: 700;
    font-size: 0.9rem;
    color: var(--primary);
    margin-bottom: 4px;
}
.method-step .step-desc {
    font-size: 0.82rem;
    color: var(--text-light);
    line-height: 1.5;
}

.footer {
    text-align: center; padding: 40px 20px; color: var(--text-light); font-size: 0.85rem;
}

@media (max-width: 768px) {
    .hero h1, .detail-hero h1 { font-size: 1.6rem; }
    .paper-header { flex-direction: column; }
    .stats-bar { gap: 12px; }
    .stat-item { flex: 1; min-width: 80px; padding: 12px; }
    .figures-row { grid-template-columns: 1fr; }
    .method-steps { flex-direction: column; }
    .method-step:not(:last-child)::after {
        content: "\2193";
        right: 50%; bottom: -14px; top: auto;
        transform: translateX(50%);
    }
}