/* Design System Variables */
:root {
    /* Colors - Swiss Modernism 2.0 */
    --color-primary: #18181B;
    --color-on-primary: #FFFFFF;
    --color-secondary: #3F3F46;
    --color-accent: #EC4899;
    --color-background: #FAFAFA;
    --color-foreground: #09090B;
    --color-muted: #E8ECF0;
    --color-border: #E4E4E7;
    --color-destructive: #DC2626;
    --color-ring: #18181B;

    /* Warm color variants */
    --color-warm-50: #FDF2F8;
    --color-warm-100: #FCE7F3;
    --color-warm-200: #FBCFE8;
    --color-warm-300: #F9A8D4;
    --color-warm-400: #F472B6;
    --color-warm-500: #EC4899;
    --color-warm-600: #DB2777;
    --color-warm-700: #BE185D;
    --color-warm-800: #9D174D;
    --color-warm-900: #831843;

    /* Typography */
    --font-display: 'Caveat', cursive;
    --font-body: 'Quicksand', sans-serif;

    /* Font Sizes */
    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.875rem;
    --text-4xl: 2.25rem;
    --text-5xl: 3rem;
    --text-6xl: 3.75rem;

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;

    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.375rem;
    --radius-lg: 0.5rem;
    --radius-xl: 0.75rem;
    --radius-2xl: 1rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;

    /* Z-index */
    --z-10: 10;
    --z-20: 20;
    --z-30: 30;
    --z-40: 40;
    --z-50: 50;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-body);
    font-size: var(--text-base);
    line-height: 1.6;
    color: var(--color-foreground);
    background-color: var(--color-background);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Accessibility: Respect reduced motion */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus States */
:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
    border-radius: var(--radius-sm);
}

/* Skip Link */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-primary);
    color: var(--color-on-primary);
    padding: var(--space-2) var(--space-4);
    z-index: var(--z-50);
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: 0;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-4);
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(250, 250, 250, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: var(--z-40);
    transition: background var(--transition-base);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-4);
}

.nav-logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--color-primary);
}

.logo-text {
    font-family: var(--font-display);
    font-size: var(--text-2xl);
    font-weight: 700;
    color: var(--color-accent);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.nav-link {
    text-decoration: none;
    color: var(--color-secondary);
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-accent);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--color-accent);
    border-radius: var(--radius-full);
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--color-primary);
    cursor: pointer;
    padding: var(--space-2);
}

/* Hero Section */
.hero {
    padding: var(--space-24) 0 var(--space-16);
    margin-top: 64px;
    background: linear-gradient(135deg, var(--color-warm-50) 0%, var(--color-background) 100%);
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-12);
    align-items: center;
}

.hero-title {
    font-family: var(--font-display);
    font-size: var(--text-5xl);
    line-height: 1.1;
    margin-bottom: var(--space-6);
}

.title-line {
    display: block;
}

.title-line.accent {
    color: var(--color-accent);
}

.hero-description {
    font-size: var(--text-lg);
    color: var(--color-secondary);
    margin-bottom: var(--space-8);
    max-width: 500px;
}

.hero-stats {
    display: flex;
    gap: var(--space-8);
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-family: var(--font-display);
    font-size: var(--text-3xl);
    font-weight: 700;
    color: var(--color-accent);
}

.stat-label {
    font-size: var(--text-sm);
    color: var(--color-secondary);
}

.hero-visual {
    display: flex;
    justify-content: center;
}

.visual-card {
    background: white;
    border-radius: var(--radius-2xl);
    padding: var(--space-6);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: var(--space-4);
    max-width: 400px;
    transform: rotate(-2deg);
    transition: transform var(--transition-slow);
}

.visual-card:hover {
    transform: rotate(0deg);
}

.card-icon {
    width: 60px;
    height: 60px;
    background: var(--color-warm-100);
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-accent);
}

.card-content h3 {
    font-size: var(--text-sm);
    color: var(--color-secondary);
    margin-bottom: var(--space-1);
}

.card-content p {
    font-weight: 600;
    color: var(--color-primary);
}

/* Sections */
.section-header {
    text-align: center;
    margin-bottom: var(--space-12);
}

.section-title {
    font-family: var(--font-display);
    font-size: var(--text-4xl);
    color: var(--color-primary);
    margin-bottom: var(--space-4);
}

.section-description {
    font-size: var(--text-lg);
    color: var(--color-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Articles Section */
.articles {
    padding: var(--space-16) 0;
}

/* Filters */
.filters {
    margin-bottom: var(--space-8);
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
}

.filter-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.filter-label {
    font-weight: 600;
    color: var(--color-primary);
    font-size: var(--text-sm);
}

.filter-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}

.filter-tag {
    padding: var(--space-2) var(--space-4);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    background: white;
    color: var(--color-secondary);
    font-size: var(--text-sm);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.filter-tag:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

.filter-tag.active {
    background: var(--color-accent);
    border-color: var(--color-accent);
    color: white;
}

/* Articles Grid */
.articles-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-6);
    margin-bottom: var(--space-8);
}

.article-card {
    background: white;
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-slow);
    border: 1px solid var(--color-border);
}

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

.article-image {
    position: relative;
    height: 200px;
    background: linear-gradient(135deg, var(--color-warm-100) 0%, var(--color-warm-200) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
}

.image-placeholder {
    width: 60px;
    height: 60px;
    background: rgba(255, 255, 255, 0.8);
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-accent);
}

.article-category {
    position: absolute;
    top: var(--space-3);
    left: var(--space-3);
    background: rgba(255, 255, 255, 0.9);
    padding: var(--space-1) var(--space-3);
    border-radius: var(--radius-full);
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--color-accent);
}

.article-content {
    padding: var(--space-4);
}

.article-meta {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    margin-bottom: var(--space-3);
    font-size: var(--text-sm);
    color: var(--color-secondary);
}

.article-title {
    font-size: var(--text-lg);
    font-weight: 600;
    margin-bottom: var(--space-3);
    line-height: 1.4;
}

.article-title a {
    text-decoration: none;
    color: var(--color-primary);
    transition: color var(--transition-fast);
}

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

.article-excerpt {
    font-size: var(--text-sm);
    color: var(--color-secondary);
    margin-bottom: var(--space-4);
    line-height: 1.6;
}

.article-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}

.tag {
    padding: var(--space-1) var(--space-3);
    background: var(--color-warm-50);
    color: var(--color-accent);
    border-radius: var(--radius-full);
    font-size: var(--text-xs);
    font-weight: 500;
}

/* Load More */
.load-more {
    text-align: center;
}

.btn-load-more {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    background: white;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    color: var(--color-secondary);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-load-more:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

/* Article Detail */
.article-detail {
    padding: var(--space-16) 0;
    display: none;
}

.article-detail.active {
    display: block;
}

.detail-header {
    margin-bottom: var(--space-8);
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    color: var(--color-secondary);
    text-decoration: none;
    font-weight: 500;
    margin-bottom: var(--space-4);
    transition: color var(--transition-fast);
}

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

.detail-meta {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    font-size: var(--text-sm);
    color: var(--color-secondary);
}

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

.detail-title {
    font-family: var(--font-display);
    font-size: var(--text-4xl);
    color: var(--color-primary);
    margin-bottom: var(--space-6);
    line-height: 1.2;
}

.detail-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
    margin-bottom: var(--space-8);
}

.detail-body {
    font-size: var(--text-lg);
    line-height: 1.8;
    color: var(--color-secondary);
}

.detail-body h2 {
    font-size: var(--text-2xl);
    color: var(--color-primary);
    margin: var(--space-8) 0 var(--space-4);
    font-weight: 600;
}

.detail-body p {
    margin-bottom: var(--space-4);
}

.detail-body pre {
    background: var(--color-primary);
    color: var(--color-on-primary);
    padding: var(--space-4);
    border-radius: var(--radius-lg);
    overflow-x: auto;
    margin-bottom: var(--space-4);
    font-size: var(--text-sm);
}

.detail-body code {
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
}

.detail-footer {
    margin-top: var(--space-12);
    padding-top: var(--space-8);
    border-top: 1px solid var(--color-border);
}

.share-buttons {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    margin-bottom: var(--space-8);
}

.share-label {
    font-weight: 500;
    color: var(--color-secondary);
}

.share-btn {
    width: 40px;
    height: 40px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    background: white;
    color: var(--color-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.article-nav {
    display: flex;
    justify-content: space-between;
    gap: var(--space-4);
}

.nav-prev,
.nav-next {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    color: var(--color-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.nav-prev:hover,
.nav-next:hover {
    color: var(--color-accent);
}

/* About Section */
.about {
    padding: var(--space-16) 0;
    background: linear-gradient(135deg, var(--color-warm-50) 0%, var(--color-background) 100%);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--space-12);
    align-items: center;
}

.about-image {
    display: flex;
    justify-content: center;
}

.avatar-placeholder {
    width: 200px;
    height: 200px;
    background: linear-gradient(135deg, var(--color-warm-200) 0%, var(--color-warm-300) 100%);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.avatar-placeholder .icon {
    width: 80px;
    height: 80px;
}

.about-title {
    font-family: var(--font-display);
    font-size: var(--text-4xl);
    color: var(--color-primary);
    margin-bottom: var(--space-4);
}

.about-description {
    font-size: var(--text-lg);
    color: var(--color-secondary);
    margin-bottom: var(--space-6);
    line-height: 1.8;
}

.about-details {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    margin-bottom: var(--space-6);
}

.detail-item {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    color: var(--color-secondary);
}

.detail-item .icon {
    width: 20px;
    height: 20px;
    color: var(--color-accent);
}

.about-links {
    display: flex;
    gap: var(--space-4);
}

.social-link {
    width: 44px;
    height: 44px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-secondary);
    text-decoration: none;
    transition: all var(--transition-fast);
}

.social-link:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
    background: var(--color-warm-50);
}

/* Footer */
.footer {
    background: var(--color-primary);
    color: var(--color-on-primary);
    padding: var(--space-12) 0 var(--space-6);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--space-8);
    margin-bottom: var(--space-8);
}

.footer-title {
    font-family: var(--font-display);
    font-size: var(--text-2xl);
    margin-bottom: var(--space-4);
    color: var(--color-accent);
}

.footer-description {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.6;
}

.footer-subtitle {
    font-size: var(--text-lg);
    font-weight: 600;
    margin-bottom: var(--space-4);
}

.footer-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--color-accent);
}

.footer-links li {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.footer-links .icon {
    width: 16px;
    height: 16px;
}

.footer-bottom {
    padding-top: var(--space-6);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    color: rgba(255, 255, 255, 0.5);
    font-size: var(--text-sm);
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: var(--space-6);
    right: var(--space-6);
    width: 48px;
    height: 48px;
    background: var(--color-accent);
    color: white;
    border: none;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-slow);
    z-index: var(--z-30);
    box-shadow: var(--shadow-lg);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--color-warm-600);
    transform: translateY(-2px);
}

/* Icon Styles */
.icon {
    width: 20px;
    height: 20px;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-description {
        max-width: 100%;
    }

    .hero-stats {
        justify-content: center;
    }

    .hero-visual {
        display: none;
    }

    .articles-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .about-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .about-details {
        align-items: center;
    }

    .about-links {
        justify-content: center;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-links {
        align-items: center;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: rgba(250, 250, 250, 0.95);
        backdrop-filter: blur(10px);
        flex-direction: column;
        padding: var(--space-4);
        border-bottom: 1px solid var(--color-border);
    }

    .nav-links.active {
        display: flex;
    }

    .nav-toggle {
        display: block;
    }

    .hero-title {
        font-size: var(--text-4xl);
    }

    .section-title {
        font-size: var(--text-3xl);
    }

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

    .filter-tags {
        justify-content: center;
    }

    .detail-title {
        font-size: var(--text-3xl);
    }

    .article-nav {
        flex-direction: column;
        gap: var(--space-4);
    }

    .footer-content {
        gap: var(--space-6);
    }
}

@media (max-width: 480px) {
    .hero {
        padding: var(--space-16) 0 var(--space-12);
    }

    .hero-title {
        font-size: var(--text-3xl);
    }

    .hero-stats {
        flex-direction: column;
        gap: var(--space-4);
    }

    .container {
        padding: 0 var(--space-3);
    }

    .article-image {
        height: 160px;
    }
}

/* Print Styles */
@media print {
    .nav,
    .back-to-top,
    .filters,
    .load-more {
        display: none !important;
    }

    body {
        color: black;
        background: white;
    }

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