/* =============================================
   NewsFilter Design System
   Dark Navy + Light Content Hybrid Theme
   ============================================= */

/* === Custom Properties === */
:root {
    /* Brand */
    --nf-primary: #1e3a5f;
    --nf-primary-light: #2d5a8e;
    --nf-primary-dark: #0f2440;
    --nf-accent: #3B82F6;
    --nf-accent-light: #60A5FA;
    --nf-accent-dark: #2563EB;

    /* Backgrounds */
    --nf-bg: #f8fafc;
    --nf-bg-card: #ffffff;
    --nf-bg-dark: #0f172a;
    --nf-bg-header: #1e293b;
    --nf-bg-hover: #f1f5f9;
    --nf-bg-elevated: #ffffff;

    /* Text */
    --nf-text: #1e293b;
    --nf-text-secondary: #64748b;
    --nf-text-muted: #94a3b8;
    --nf-text-inverse: #ffffff;
    --nf-text-link: #3B82F6;

    /* Borders */
    --nf-border: #e2e8f0;
    --nf-border-light: #f1f5f9;
    --nf-border-dark: #334155;

    /* Radius */
    --nf-radius: 12px;
    --nf-radius-sm: 8px;
    --nf-radius-lg: 16px;
    --nf-radius-xl: 24px;
    --nf-radius-pill: 999px;

    /* Shadows */
    --nf-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
    --nf-shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
    --nf-shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.08);
    --nf-shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.1);

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

    /* Transitions */
    --nf-transition: 0.2s ease;
    --nf-transition-slow: 0.3s ease;

    /* Source Colors */
    --nf-reddit: #FF4500;
    --nf-hn: #FF6600;

    /* Layout */
    --nf-header-height: 60px;
    --nf-content-width: 900px;
    --nf-content-wide: 1100px;
}

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

body.newsfilter-page {
    font-family: var(--nf-font);
    background: var(--nf-bg);
    color: var(--nf-text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
}

img {
    max-width: 100%;
    display: block;
}

/* === Scrollbar === */
body.newsfilter-page::-webkit-scrollbar { width: 6px; }
body.newsfilter-page::-webkit-scrollbar-track { background: var(--nf-bg); }
body.newsfilter-page::-webkit-scrollbar-thumb { background: var(--nf-text-muted); border-radius: 3px; }

/* === Utility === */
.nf-spin {
    animation: nf-spin 1s linear infinite;
}
@keyframes nf-spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* =============================================
   Header
   ============================================= */
.nf-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--nf-bg-header);
    border-bottom: 1px solid var(--nf-border-dark);
    height: var(--nf-header-height);
}

.nf-header-inner {
    max-width: var(--nf-content-wide);
    margin: 0 auto;
    padding: 0 1.5rem;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1.5rem;
}

.nf-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--nf-text-inverse);
    font-weight: 700;
    font-size: 1.25rem;
    white-space: nowrap;
}

.nf-logo .material-icons-round {
    font-size: 24px;
    color: var(--nf-accent);
}

.nf-nav {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.nf-nav-link {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.5rem 0.85rem;
    color: var(--nf-text-muted);
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: var(--nf-radius-sm);
    transition: color var(--nf-transition), background var(--nf-transition);
}

.nf-nav-link:hover {
    color: var(--nf-text-inverse);
    background: rgba(255, 255, 255, 0.08);
}

.nf-header-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.nf-demo-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.25rem 0.6rem;
    background: rgba(251, 191, 36, 0.15);
    color: #FBBF24;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--nf-radius-pill);
    border: 1px solid rgba(251, 191, 36, 0.3);
}

.nf-user-name {
    color: var(--nf-text-inverse);
    font-size: 0.875rem;
    font-weight: 500;
}

/* =============================================
   Buttons
   ============================================= */
.nf-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.6rem 1.25rem;
    font-family: var(--nf-font);
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: var(--nf-radius-sm);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all var(--nf-transition);
    white-space: nowrap;
    line-height: 1.4;
}

.nf-btn-sm {
    padding: 0.35rem 0.85rem;
    font-size: 0.8125rem;
}

.nf-btn-lg {
    padding: 0.85rem 1.75rem;
    font-size: 1rem;
    border-radius: var(--nf-radius);
}

.nf-btn-primary {
    background: var(--nf-accent);
    color: #fff;
    border-color: var(--nf-accent);
}
.nf-btn-primary:hover {
    background: var(--nf-accent-dark);
    border-color: var(--nf-accent-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.nf-btn-outline {
    background: transparent;
    color: var(--nf-text-inverse);
    border-color: rgba(255, 255, 255, 0.3);
}
.nf-btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.5);
}

/* =============================================
   Hero Section (Landing Page)
   ============================================= */
.nf-hero {
    position: relative;
    min-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(160deg, #0f172a 0%, #1e3a5f 40%, #1e293b 100%);
    overflow: hidden;
    padding: 2rem 1.5rem;
}

.nf-hero-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 60% 50% at 70% 30%, rgba(59, 130, 246, 0.12) 0%, transparent 70%),
        radial-gradient(ellipse 40% 40% at 20% 70%, rgba(139, 92, 246, 0.08) 0%, transparent 70%);
    pointer-events: none;
}

.nf-hero-content {
    position: relative;
    max-width: 680px;
    text-align: center;
    z-index: 1;
}

.nf-hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.4rem 1rem;
    background: rgba(59, 130, 246, 0.12);
    color: var(--nf-accent-light);
    font-size: 0.8125rem;
    font-weight: 600;
    border-radius: var(--nf-radius-pill);
    border: 1px solid rgba(59, 130, 246, 0.2);
    margin-bottom: 1.5rem;
}

.nf-hero h1 {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.2;
    color: var(--nf-text-inverse);
    margin-bottom: 1.25rem;
    letter-spacing: -0.02em;
}

.nf-gradient-text {
    background: linear-gradient(135deg, #60A5FA, #A78BFA, #60A5FA);
    background-size: 200% auto;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: nf-gradient-shift 4s ease-in-out infinite;
}

@keyframes nf-gradient-shift {
    0%, 100% { background-position: 0% center; }
    50% { background-position: 100% center; }
}

.nf-hero-subtitle {
    font-size: 1.1rem;
    color: var(--nf-text-muted);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.nf-hero-cta {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
}

.nf-hero-sources {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
}

.nf-hero-sources-label {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--nf-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.nf-hero-source-badges {
    display: flex;
    gap: 0.75rem;
}

.nf-source-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.4rem 0.85rem;
    border-radius: var(--nf-radius-pill);
    font-size: 0.8125rem;
    font-weight: 600;
    color: #fff;
}

.nf-source-pill.nf-source-reddit {
    background: rgba(255, 69, 0, 0.15);
    color: #FF6B35;
    border: 1px solid rgba(255, 69, 0, 0.25);
}

.nf-source-pill.nf-source-hn {
    background: rgba(255, 102, 0, 0.15);
    color: #FF8533;
    border: 1px solid rgba(255, 102, 0, 0.25);
}

/* =============================================
   Sections (Landing Page)
   ============================================= */
.nf-section {
    padding: 5rem 1.5rem;
}

.nf-section-gray {
    background: #f1f5f9;
}

.nf-section-cta {
    background: linear-gradient(160deg, #0f172a, #1e3a5f);
    color: var(--nf-text-inverse);
}

.nf-section-cta h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.nf-section-cta p {
    color: var(--nf-text-muted);
    margin-bottom: 2rem;
}

.nf-section-inner {
    max-width: var(--nf-content-width);
    margin: 0 auto;
}

.nf-section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.nf-section-label {
    display: inline-block;
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--nf-accent);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 0.75rem;
}

.nf-section-header h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--nf-text);
    margin-bottom: 0.75rem;
    letter-spacing: -0.01em;
}

.nf-section-header p {
    font-size: 1.05rem;
    color: var(--nf-text-secondary);
}

/* Steps */
.nf-steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.nf-step {
    position: relative;
    text-align: center;
    padding: 2rem 1.5rem;
    background: var(--nf-bg-card);
    border-radius: var(--nf-radius-lg);
    border: 1px solid var(--nf-border);
    transition: transform var(--nf-transition), box-shadow var(--nf-transition);
}

.nf-step:hover {
    transform: translateY(-4px);
    box-shadow: var(--nf-shadow-lg);
}

.nf-step-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    margin: 0 auto 1rem;
    background: rgba(59, 130, 246, 0.1);
    color: var(--nf-accent);
    border-radius: var(--nf-radius);
}

.nf-step-icon .material-icons-round {
    font-size: 28px;
}

.nf-step-number {
    position: absolute;
    top: 1rem;
    right: 1rem;
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--nf-accent);
    color: #fff;
    font-size: 0.75rem;
    font-weight: 700;
    border-radius: 50%;
}

.nf-step h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--nf-text);
}

.nf-step p {
    font-size: 0.9rem;
    color: var(--nf-text-secondary);
    line-height: 1.6;
}

/* Category Showcase */
.nf-categories-showcase {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.25rem;
}

.nf-showcase-card {
    padding: 1.5rem;
    background: var(--nf-bg-card);
    border-radius: var(--nf-radius);
    border: 1px solid var(--nf-border);
    transition: all var(--nf-transition);
    cursor: default;
}

.nf-showcase-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--nf-shadow-md);
    border-color: var(--card-color, var(--nf-accent));
}

.nf-showcase-card .material-icons-round {
    font-size: 32px;
    color: var(--card-color, var(--nf-accent));
    margin-bottom: 0.75rem;
    display: block;
}

.nf-showcase-card h4 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 0.35rem;
    color: var(--nf-text);
}

.nf-showcase-card p {
    font-size: 0.8125rem;
    color: var(--nf-text-secondary);
    line-height: 1.5;
}

/* =============================================
   Feed Layout
   ============================================= */
.nf-feed-layout {
    min-height: calc(100vh - var(--nf-header-height));
    padding-top: 0;
}

/* Category Filter Bar */
.nf-category-bar {
    position: sticky;
    top: var(--nf-header-height);
    z-index: 50;
    background: var(--nf-bg-card);
    border-bottom: 1px solid var(--nf-border);
    padding: 0.75rem 0;
    box-shadow: var(--nf-shadow);
}

.nf-category-bar-inner {
    max-width: var(--nf-content-width);
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    gap: 0.5rem;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.nf-category-bar-inner::-webkit-scrollbar {
    display: none;
}

.nf-category-chip {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.45rem 0.95rem;
    background: transparent;
    color: var(--nf-text-secondary);
    font-family: var(--nf-font);
    font-size: 0.8125rem;
    font-weight: 500;
    border: 1px solid var(--nf-border);
    border-radius: var(--nf-radius-pill);
    cursor: pointer;
    white-space: nowrap;
    transition: all var(--nf-transition);
    flex-shrink: 0;
}

.nf-category-chip:hover {
    background: var(--nf-bg-hover);
    color: var(--nf-text);
    border-color: var(--nf-text-muted);
}

.nf-category-chip.active {
    background: var(--chip-color, var(--nf-accent));
    color: #fff;
    border-color: var(--chip-color, var(--nf-accent));
}

/* Date Filter Bar */
.nf-date-bar {
    background: var(--nf-bg-card);
    border-bottom: 1px solid var(--nf-border);
    padding: 0.5rem 0;
}

.nf-date-bar-inner {
    max-width: var(--nf-content-width);
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
}

.nf-date-bar-inner::-webkit-scrollbar {
    display: none;
}

.nf-date-bar-label {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    color: var(--nf-text-muted);
    font-size: 0.75rem;
    font-weight: 600;
    white-space: nowrap;
    margin-right: 0.25rem;
    flex-shrink: 0;
}

.nf-date-chip {
    display: inline-flex;
    align-items: center;
    padding: 0.3rem 0.75rem;
    background: transparent;
    color: var(--nf-text-secondary);
    font-family: var(--nf-font);
    font-size: 0.75rem;
    font-weight: 500;
    border: 1px solid var(--nf-border);
    border-radius: var(--nf-radius-pill);
    cursor: pointer;
    white-space: nowrap;
    transition: all var(--nf-transition);
    flex-shrink: 0;
}

.nf-date-chip:hover {
    background: var(--nf-bg-hover);
    color: var(--nf-text);
    border-color: var(--nf-text-muted);
}

.nf-date-chip.active {
    background: var(--nf-primary);
    color: #fff;
    border-color: var(--nf-primary);
}

/* Feed Content Area */
.nf-feed-content {
    max-width: var(--nf-content-width);
    margin: 0 auto;
    padding: 1.5rem;
}

.nf-feed-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.25rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.nf-feed-title {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--nf-text);
}

.nf-feed-title .material-icons-round {
    font-size: 24px;
    color: var(--nf-accent);
}

.nf-article-count {
    font-size: 0.875rem;
    color: var(--nf-text-secondary);
}

.nf-article-count strong {
    color: var(--nf-accent);
    font-weight: 700;
}

/* =============================================
   Article Card
   ============================================= */
.nf-article-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.nf-article-card {
    background: var(--nf-bg-card);
    border: 1px solid var(--nf-border);
    border-radius: var(--nf-radius);
    padding: 1.25rem 1.5rem;
    transition: border-color var(--nf-transition), box-shadow var(--nf-transition);
}

.nf-article-card:hover {
    border-color: var(--nf-text-muted);
    box-shadow: var(--nf-shadow-md);
}

/* Article Meta Row */
.nf-article-meta {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.6rem;
    flex-wrap: wrap;
}

.nf-category-tag {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.2rem 0.6rem;
    color: #fff;
    font-size: 0.6875rem;
    font-weight: 600;
    border-radius: var(--nf-radius-pill);
    line-height: 1.4;
}

.nf-source-badge {
    display: inline-flex;
    align-items: center;
    padding: 0.2rem 0.55rem;
    font-size: 0.6875rem;
    font-weight: 700;
    border-radius: var(--nf-radius-pill);
    line-height: 1.4;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.nf-source-badge.nf-source-reddit {
    background: rgba(255, 69, 0, 0.1);
    color: var(--nf-reddit);
}

.nf-source-badge.nf-source-hackernews {
    background: rgba(255, 102, 0, 0.1);
    color: var(--nf-hn);
}

.nf-trending-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.2rem;
    padding: 0.2rem 0.55rem;
    background: linear-gradient(135deg, #FF6B35, #EF4444);
    color: #fff;
    font-size: 0.6875rem;
    font-weight: 700;
    border-radius: var(--nf-radius-pill);
    line-height: 1.4;
}

/* Article Title */
.nf-article-title {
    font-size: 1.05rem;
    font-weight: 700;
    line-height: 1.45;
    margin-bottom: 0.4rem;
}

.nf-article-title a {
    color: var(--nf-text);
    transition: color var(--nf-transition);
}

.nf-article-title a:hover {
    color: var(--nf-accent);
}

/* Article Summary */
.nf-article-summary {
    font-size: 0.875rem;
    color: var(--nf-text-secondary);
    line-height: 1.6;
    margin-bottom: 0.75rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* Article Footer */
.nf-article-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.nf-article-stats {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.nf-stat {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    font-size: 0.8125rem;
    color: var(--nf-text-muted);
}

.nf-stat .material-icons-round {
    font-size: 16px;
}

.nf-comment-toggle {
    cursor: pointer;
    border-radius: var(--nf-radius-sm);
    padding: 0.15rem 0.4rem;
    margin: -0.15rem -0.4rem;
    transition: background var(--nf-transition), color var(--nf-transition);
}

.nf-comment-toggle:hover {
    background: rgba(59, 130, 246, 0.08);
    color: var(--nf-accent);
}

.nf-article-author {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    font-size: 0.8125rem;
    color: var(--nf-text-muted);
}

/* =============================================
   Comments Section
   ============================================= */
.nf-comments-section {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--nf-border-light);
}

.nf-comments-loading {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1.5rem;
    color: var(--nf-text-muted);
    font-size: 0.875rem;
}

.nf-comments-list {
    display: flex;
    flex-direction: column;
    gap: 0.85rem;
    margin-bottom: 1.25rem;
}

.nf-comment {
    padding: 0.85rem 1rem;
    background: var(--nf-bg);
    border-radius: var(--nf-radius-sm);
    border: 1px solid var(--nf-border-light);
}

.nf-comment-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.4rem;
    flex-wrap: wrap;
}

.nf-comment-nickname {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--nf-text);
}

.nf-comment-ip {
    font-size: 0.6875rem;
    font-family: 'Courier New', Courier, monospace;
    color: var(--nf-text-muted);
    background: var(--nf-border-light);
    padding: 0.1rem 0.35rem;
    border-radius: 4px;
}

.nf-comment-flag {
    font-size: 0.875rem;
    line-height: 1;
}

.nf-comment-time {
    font-size: 0.75rem;
    color: var(--nf-text-muted);
    margin-left: auto;
}

.nf-comment-content {
    font-size: 0.875rem;
    color: var(--nf-text-secondary);
    line-height: 1.6;
    word-break: break-word;
}

.nf-no-comments {
    text-align: center;
    padding: 1.5rem;
    color: var(--nf-text-muted);
    font-size: 0.875rem;
}

/* Comment Form */
.nf-comment-form {
    display: flex;
    flex-direction: column;
    gap: 0.65rem;
}

.nf-input,
.nf-textarea {
    width: 100%;
    padding: 0.6rem 0.85rem;
    font-family: var(--nf-font);
    font-size: 0.875rem;
    color: var(--nf-text);
    background: var(--nf-bg);
    border: 1px solid var(--nf-border);
    border-radius: var(--nf-radius-sm);
    outline: none;
    transition: border-color var(--nf-transition), box-shadow var(--nf-transition);
}

.nf-input:focus,
.nf-textarea:focus {
    border-color: var(--nf-accent);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.nf-textarea {
    min-height: 80px;
    resize: vertical;
}

.nf-comment-user {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--nf-text);
    padding: 0.4rem 0;
}

.nf-comment-form .nf-btn {
    align-self: flex-end;
}

/* =============================================
   Empty State
   ============================================= */
.nf-empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 4rem 2rem;
    text-align: center;
}

.nf-empty-state h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--nf-text);
    margin-top: 1rem;
    margin-bottom: 0.5rem;
}

.nf-empty-state p {
    font-size: 0.9rem;
    color: var(--nf-text-secondary);
}

/* =============================================
   Login Page
   ============================================= */
.nf-login-wrapper {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(160deg, #0f172a, #1e3a5f);
    padding: 2rem;
}

.nf-login-card {
    width: 100%;
    max-width: 400px;
    padding: 2.5rem;
    background: var(--nf-bg-card);
    border-radius: var(--nf-radius-lg);
    box-shadow: var(--nf-shadow-xl);
    text-align: center;
}

.nf-login-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--nf-primary);
    margin-bottom: 0.5rem;
}

.nf-login-logo .material-icons-round {
    font-size: 32px;
    color: var(--nf-accent);
}

.nf-login-subtitle {
    font-size: 0.95rem;
    color: var(--nf-text-secondary);
    margin-bottom: 2rem;
}

.nf-login-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.65rem;
    width: 100%;
    padding: 0.75rem 1.25rem;
    font-family: var(--nf-font);
    font-size: 0.9375rem;
    font-weight: 600;
    border: 1px solid var(--nf-border);
    border-radius: var(--nf-radius-sm);
    background: var(--nf-bg-card);
    color: var(--nf-text);
    cursor: pointer;
    transition: all var(--nf-transition);
    margin-bottom: 0.75rem;
}

.nf-login-btn:hover {
    background: var(--nf-bg-hover);
    border-color: var(--nf-text-muted);
}

.nf-login-kakao {
    background: #FEE500;
    color: #191919;
    border-color: #FEE500;
}
.nf-login-kakao:hover {
    background: #F5DC00;
    border-color: #F5DC00;
}

.nf-login-demo {
    color: var(--nf-accent);
    border-style: dashed;
}
.nf-login-demo:hover {
    background: rgba(59, 130, 246, 0.05);
    border-color: var(--nf-accent);
}

.nf-login-divider {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin: 0.75rem 0;
    color: var(--nf-text-muted);
    font-size: 0.8125rem;
}

.nf-login-divider::before,
.nf-login-divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--nf-border);
}

.nf-login-help {
    margin-top: 1.5rem;
    font-size: 0.8125rem;
    color: var(--nf-text-muted);
}

.nf-login-help a {
    color: var(--nf-accent);
    font-weight: 500;
}
.nf-login-help a:hover {
    text-decoration: underline;
}

/* =============================================
   Footer
   ============================================= */
.nf-footer {
    background: var(--nf-bg-dark);
    color: var(--nf-text-muted);
    padding: 2rem 1.5rem;
    text-align: center;
    font-size: 0.8125rem;
}

.nf-footer-inner {
    max-width: var(--nf-content-width);
    margin: 0 auto;
}

.nf-footer-links {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 0.75rem;
}

.nf-footer-links a {
    color: var(--nf-text-muted);
    transition: color var(--nf-transition);
}

.nf-footer-links a:hover {
    color: var(--nf-text-inverse);
}

.nf-footer p {
    color: #475569;
}

/* =============================================
   Responsive Design (Mobile-First Overrides)
   ============================================= */
@media (max-width: 768px) {
    /* Hero */
    .nf-hero {
        min-height: 80vh;
        padding: 2rem 1.25rem;
    }

    .nf-hero h1 {
        font-size: 2rem;
    }

    .nf-hero-subtitle {
        font-size: 0.95rem;
    }

    .nf-hero-cta {
        flex-direction: column;
        gap: 0.75rem;
    }

    .nf-hero-cta .nf-btn {
        width: 100%;
    }

    /* Header */
    .nf-header-inner {
        padding: 0 1rem;
    }

    .nf-logo-text {
        display: none;
    }

    .nf-nav-link span:last-child {
        display: none;
    }

    /* Steps */
    .nf-steps {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    /* Category Showcase */
    .nf-categories-showcase {
        grid-template-columns: repeat(2, 1fr);
        gap: 0.85rem;
    }

    .nf-showcase-card {
        padding: 1.25rem;
    }

    .nf-showcase-card .material-icons-round {
        font-size: 28px;
    }

    /* Section */
    .nf-section {
        padding: 3rem 1.25rem;
    }

    .nf-section-header h2 {
        font-size: 1.5rem;
    }

    .nf-section-cta h2 {
        font-size: 1.5rem;
    }

    /* Feed */
    .nf-feed-content {
        padding: 1rem;
    }

    .nf-article-card {
        padding: 1rem;
    }

    .nf-article-title {
        font-size: 0.95rem;
    }

    .nf-article-footer {
        flex-direction: column;
        align-items: flex-start;
    }

    /* Category Bar */
    .nf-category-bar-inner {
        padding: 0 1rem;
    }

    .nf-category-chip {
        font-size: 0.75rem;
        padding: 0.35rem 0.75rem;
    }

    /* Login */
    .nf-login-card {
        padding: 2rem 1.5rem;
    }

    /* Footer */
    .nf-footer-links {
        flex-direction: column;
        gap: 0.75rem;
    }
}

@media (max-width: 480px) {
    .nf-hero h1 {
        font-size: 1.65rem;
    }

    .nf-categories-showcase {
        grid-template-columns: 1fr;
    }

    .nf-hero-source-badges {
        flex-direction: column;
        align-items: center;
    }

    .nf-article-meta {
        gap: 0.35rem;
    }

    .nf-article-stats {
        gap: 0.65rem;
    }
}

/* =============================================
   Print Styles
   ============================================= */
@media print {
    .nf-header,
    .nf-category-bar,
    .nf-footer,
    .nf-comments-section,
    .nf-comment-form {
        display: none !important;
    }

    .nf-article-card {
        break-inside: avoid;
        border: 1px solid #ccc;
        box-shadow: none;
    }
}