:root {
    --primary-blue: #0A2540;
    --secondary-blue: #1E3A5F;
    --accent-green: #00D4AA;
    --accent-teal: #00B4D8;
    --text-dark: #1A1A2E;
    --text-light: #667188;
    --bg-light: #F8FAFC;
    --bg-white: #FFFFFF;
    --border-color: #E2E8F0;
    --shadow-sm: 0 1px 3px rgba(10, 37, 64, 0.08);
    --shadow-md: 0 4px 12px rgba(10, 37, 64, 0.12);
    --shadow-lg: 0 8px 24px rgba(10, 37, 64, 0.16);
}

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

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

header {
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--secondary-blue) 100%);
    color: white;
    padding: 0;
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    padding: 16px 0;
}

nav .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    color: white;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-links a {
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

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

.hero {
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--secondary-blue) 100%);
    color: white;
    padding: 80px 0;
    text-align: center;
    margin-bottom: 48px;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 16px;
    letter-spacing: -1px;
}

.hero p {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.85);
    max-width: 600px;
    margin: 0 auto;
}

.posts-section {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 24px;
    margin-bottom: 64px;
}

.post-card {
    background: var(--bg-white);
    border-radius: 12px;
    padding: 28px;
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    border: 1px solid var(--border-color);
}

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

.post-card h3 {
    margin-bottom: 12px;
}

.post-card h3 a {
    color: var(--primary-blue);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s ease;
}

.post-card h3 a:hover {
    color: var(--accent-green);
}

.post-date {
    color: var(--text-light);
    font-size: 0.875rem;
    margin-bottom: 12px;
}

.post-excerpt {
    color: var(--text-dark);
    line-height: 1.6;
}

.archive-header {
    text-align: center;
    padding: 48px 0;
    margin-bottom: 32px;
}

.archive-header h1 {
    font-size: 2.5rem;
    color: var(--primary-blue);
    margin-bottom: 12px;
}

.archive-header p {
    color: var(--text-light);
    font-size: 1.125rem;
}

.archive-item {
    background: var(--bg-white);
    border-radius: 8px;
    padding: 24px;
    margin-bottom: 16px;
    box-shadow: var(--shadow-sm);
    border-left: 4px solid var(--accent-green);
}

.archive-item h3 a {
    color: var(--primary-blue);
    text-decoration: none;
    font-weight: 600;
}

.archive-item h3 a:hover {
    color: var(--accent-teal);
}

article.post {
    background: var(--bg-white);
    border-radius: 12px;
    padding: 48px;
    margin: 48px auto;
    max-width: 800px;
    box-shadow: var(--shadow-md);
}

.post-header {
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 24px;
    margin-bottom: 32px;
}

.post-header h1 {
    font-size: 2.25rem;
    color: var(--primary-blue);
    margin-bottom: 12px;
    line-height: 1.3;
}

.post-content {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--text-dark);
}

.post-content p {
    margin-bottom: 20px;
}

.post-footer {
    margin-top: 48px;
    padding-top: 24px;
    border-top: 1px solid var(--border-color);
}

.back-link {
    display: inline-block;
    color: var(--accent-teal);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

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

footer {
    background: var(--primary-blue);
    color: white;
    padding: 32px 0;
    margin-top: 64px;
}

footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

footer p {
    color: rgba(255, 255, 255, 0.75);
}

footer a {
    color: var(--accent-green);
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .posts-section {
        grid-template-columns: 1fr;
    }
    
    article.post {
        padding: 24px;
        margin: 24px 16px;
    }
    
    footer .container {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
}