@import url('https://fonts.googleapis.com/css2?family=Crimson+Pro:wght@400;700;900&family=Inter:wght@400;500;600&display=swap');

:root {
    --bg-primary: #FFFFFF;
    --bg-secondary: #F8F9FA;
    --bg-hero: #EBEBEB;
    --brand-blue: #1746A2;
    --text-primary: #000000;
    --text-secondary: #666666;
    --border-light: #DDDDDD;
    --border-extra-light: #EEEEEE;
    --serif-font: 'Crimson Pro', serif;
    --sans-font: 'Inter', sans-serif;
    --hero-dark: #0f172a;
    --hero-accent: #3b82f6;
}

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

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--sans-font);
    line-height: 1.5;
}

a {
    color: var(--brand-blue);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Header */
header {
    background: #FFFFFF;
    border-bottom: 1px solid var(--border-light);
    height: 64px;
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.brand {
    font-family: var(--serif-font);
    font-weight: 900;
    font-size: 1.5rem;
    color: var(--text-primary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.brand span {
    color: var(--brand-blue);
}

.nav-links {
    display: flex;
    gap: 1.5rem;
    align-items: center;
    font-size: 0.9rem;
    font-weight: 500;
}

.nav-links a {
    color: var(--text-secondary);
}

.nav-links a.active {
    color: var(--brand-blue);
    font-weight: 600;
}

.search-mock {
    background: #F0F1F2;
    border: 1px solid var(--border-light);
    border-radius: 4px;
    padding: 0.4rem 1rem;
    width: 300px;
    color: var(--text-secondary);
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Topic Hero (Section Header) */
/* New Premium Hero Section */
.hero-premium {
    position: relative;
    padding: 8rem 0;
    background-color: var(--hero-dark);
    background-image: url('/hero-bg.png');
    background-size: cover;
    background-position: center;
    color: #FFFFFF;
    overflow: hidden;
    text-align: center;
}

.hero-premium::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at center, rgba(15, 23, 42, 0.4) 0%, rgba(15, 23, 42, 0.9) 100%);
    z-index: 1;
}

.hero-container {
    position: relative;
    z-index: 2;
}

.hero-badge {
    display: inline-block;
    background: rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(59, 130, 246, 0.3);
    color: var(--hero-accent);
    padding: 0.5rem 1.2rem;
    border-radius: 99px;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 2rem;
    animation: fadeInUp 0.8s ease-out;
}

.hero-h1 {
    font-family: var(--serif-font);
    font-size: 4.5rem;
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, #FFFFFF 0%, #94a3b8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: fadeInUp 1s ease-out 0.2s both;
}

.hero-p {
    font-size: 1.25rem;
    color: #94a3b8;
    max-width: 700px;
    margin: 0 auto 3rem;
    line-height: 1.6;
    animation: fadeInUp 1s ease-out 0.4s both;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    animation: fadeInUp 1s ease-out 0.6s both;
}

.btn-hero-primary {
    background: var(--hero-accent);
    color: #FFFFFF;
    padding: 1rem 2.5rem;
    border-radius: 8px;
    font-weight: 700;
    font-size: 1rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 10px 20px -5px rgba(59, 130, 246, 0.5);
    border: none;
    cursor: pointer;
}

.btn-hero-primary:hover {
    transform: translateY(-2px);
    background: #2563eb;
    box-shadow: 0 15px 25px -5px rgba(59, 130, 246, 0.6);
    text-decoration: none;
    color: #FFF;
}

.btn-hero-secondary {
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: #FFFFFF;
    padding: 1rem 2.5rem;
    border-radius: 8px;
    font-weight: 700;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.btn-hero-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.3);
    text-decoration: none;
    color: #FFF;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.topic-hero {
    background: var(--bg-hero);
    padding: 3rem 0;
    border-bottom: 1px solid var(--border-light);
}

.breadcrumbs {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
    text-transform: uppercase;
}

.topic-title {
    font-family: var(--serif-font);
    font-size: 3rem;
    font-weight: 900;
    margin-bottom: 1rem;
    line-height: 1.1;
}

.topic-meta {
    display: flex;
    gap: 1.5rem;
    align-items: center;
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-bottom: 1.5rem;
}

.btn-follow {
    background: var(--brand-blue);
    color: white;
    padding: 0.5rem 1.5rem;
    border-radius: 20px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: background 0.3s;
}

.btn-follow:hover {
    background: #12377a;
    text-decoration: none;
}

/* Page Layout */
.page-layout {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 4rem;
    padding: 1.5rem 0;
}

/* Content Feed */
.content-feed {
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
}

.doc-card {
    border-bottom: 1px solid var(--border-extra-light);
    padding-bottom: 1.5rem;
}

.doc-card:last-child {
    border-bottom: none;
}

.doc-title {
    font-family: var(--serif-font);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    display: block;
    color: var(--text-primary);
}

.doc-title:hover {
    text-decoration: underline;
}

.doc-meta {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.doc-snippet {
    font-size: 0.95rem;
    color: var(--text-primary);
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.doc-actions {
    display: flex;
    gap: 1rem;
}

.btn-doc-action {
    border: 1px solid var(--border-light);
    background: #FFF;
    padding: 0.4rem 1rem;
    border-radius: 4px;
    font-size: 0.8rem;
    color: var(--text-secondary);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
}

.btn-doc-action:hover {
    background: var(--bg-secondary);
    border-color: var(--text-secondary);
    text-decoration: none;
}

/* Sidebar */
.sidebar-section {
    margin-bottom: 2.5rem;
}

.sidebar-heading {
    font-size: 0.9rem;
    text-transform: uppercase;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
    border-bottom: 2px solid var(--text-primary);
    padding-bottom: 0.5rem;
}

.sidebar-list {
    list-style: none;
}

.sidebar-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-extra-light);
}

.sidebar-link {
    font-size: 0.9rem;
    color: var(--brand-blue);
    font-weight: 500;
}

.btn-mini-follow {
    font-size: 0.7rem;
    padding: 0.2rem 0.6rem;
    border: 1px solid var(--brand-blue);
    border-radius: 12px;
    color: var(--brand-blue);
    font-weight: 600;
}

/* Footer */
footer {
    padding: 4rem 0;
    margin-top: 4rem;
    border-top: 1px solid var(--border-light);
    background: var(--bg-secondary);
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* Origin Tags (matching academia follow style if needed, but keeping it for context) */
.origin-label {
    display: inline-block;
    font-size: 0.7rem;
    color: var(--text-secondary);
    background: #EEEEEE;
    padding: 0.1rem 0.4rem;
    border-radius: 3px;
    margin-left: 0.5rem;
}

/* Show View specific */
.brief-container {
    max-width: 800px;
    margin: 4rem auto;
}

.brief-body-doc {
    font-family: var(--serif-font);
    font-size: 1.15rem;
    line-height: 1.8;
}

@media (max-width: 900px) {
    .page-layout {
        grid-template-columns: 1fr;
    }
}

/* Pagination Styles */
.cf-pagination {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
    margin-top: 2rem;
}

.cf-pagination-info {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.cf-pagination-info .font-medium {
    font-weight: 700;
    color: var(--text-primary);
}

.cf-pagination-links {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.cf-page-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 8px;
    border: 1px solid var(--border-light);
    background: #FFFFFF;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 600;
    transition: all 0.2s ease;
    text-decoration: none;
}

.cf-page-btn:hover:not(.cf-disabled):not(.cf-active) {
    border-color: var(--brand-blue);
    color: var(--brand-blue);
    text-decoration: none;
}

.cf-page-btn.cf-active {
    background: var(--brand-blue);
    color: #FFFFFF;
    border-color: var(--brand-blue);
    box-shadow: 0 4px 6px rgba(23, 70, 162, 0.2);
}

.cf-page-btn.cf-disabled {
    background: var(--bg-secondary);
    color: #CCCCCC;
    border-color: var(--border-extra-light);
    cursor: not-allowed;
}

.cf-page-dots {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    color: var(--text-secondary);
    font-weight: bold;
}