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

:root {
    --bg: #ffffff;
    --bg-alt: #f8f9fa;
    --text: #1a1a2e;
    --text-secondary: #6c757d;
    --accent: #4f46e5;
    --accent-hover: #4338ca;
    --card-bg: #ffffff;
    --card-shadow: 0 2px 12px rgba(0,0,0,0.08);
    --border: #e5e7eb;
    --nav-bg: rgba(255,255,255,0.85);
}

[data-theme="dark"] {
    --bg: #0f172a;
    --bg-alt: #1e293b;
    --text: #e2e8f0;
    --text-secondary: #94a3b8;
    --accent: #818cf8;
    --accent-hover: #6366f1;
    --card-bg: #1e293b;
    --card-shadow: 0 2px 12px rgba(0,0,0,0.3);
    --border: #334155;
    --nav-bg: rgba(15,23,42,0.85);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans SC", sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    transition: background 0.3s, color 0.3s;
}

.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 24px;
}

header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: var(--nav-bg);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--accent);
    text-decoration: none;
}

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

.nav-links a {
    color: var(--text);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.2s;
}

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

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text);
    cursor: pointer;
}

.theme-toggle {
    background: none;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 4px 10px;
    font-size: 1.1rem;
    cursor: pointer;
    color: var(--text);
}

.hero {
    padding: 160px 0 80px;
    text-align: center;
}

.hero h1 {
    font-size: 2.8rem;
    margin-bottom: 12px;
}

.highlight {
    color: var(--accent);
}

.subtitle {
    font-size: 1.15rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.hero-btns {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 28px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all 0.2s;
}

.btn-primary {
    background: var(--accent);
    color: #fff;
}

.btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
}

.btn-outline {
    border: 2px solid var(--accent);
    color: var(--accent);
}

.btn-outline:hover {
    background: var(--accent);
    color: #fff;
    transform: translateY(-2px);
}

.section {
    padding: 80px 0;
}

.bg-alt {
    background: var(--bg-alt);
}

.section-title {
    font-size: 1.8rem;
    margin-bottom: 40px;
    text-align: center;
    position: relative;
}

.section-title::after {
    content: "";
    display: block;
    width: 48px;
    height: 3px;
    background: var(--accent);
    margin: 12px auto 0;
    border-radius: 2px;
}

.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}

.blog-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 28px;
    transition: transform 0.2s, box-shadow 0.2s;
    cursor: default;
}

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

.blog-card { cursor: pointer; }

.blog-card .date {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.blog-card h3 {
    font-size: 1.15rem;
    margin-bottom: 10px;
}

.blog-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 16px;
    line-height: 1.6;
}

.blog-card .tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.tag {
    font-size: 0.8rem;
    padding: 3px 10px;
    border-radius: 20px;
    background: var(--bg-alt);
    color: var(--accent);
}

.about-content {
    display: flex;
    align-items: center;
    gap: 40px;
    max-width: 640px;
    margin: 0 auto;
}

.about-avatar {
    font-size: 5rem;
    flex-shrink: 0;
}

.about-text p {
    margin-bottom: 12px;
    color: var(--text-secondary);
}

.skills {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-top: 16px;
}

.skill-tag {
    padding: 6px 14px;
    border-radius: 20px;
    background: var(--accent);
    color: #fff;
    font-size: 0.85rem;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 24px;
    flex-wrap: wrap;
}

.contact-item {
    padding: 14px 28px;
    border: 1px solid var(--border);
    border-radius: 10px;
    text-decoration: none;
    color: var(--text);
    font-size: 1rem;
    transition: all 0.2s;
}

.contact-item:hover {
    border-color: var(--accent);
    color: var(--accent);
    transform: translateY(-2px);
}

.post-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    z-index: 200;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 24px;
    backdrop-filter: blur(4px);
}

.post-overlay.open {
    display: flex;
}

.post-modal {
    background: var(--card-bg);
    border-radius: 16px;
    max-width: 700px;
    width: 100%;
    max-height: 85vh;
    overflow-y: auto;
    padding: 40px;
    position: relative;
    border: 1px solid var(--border);
}

.post-close {
    position: absolute;
    top: 16px;
    right: 16px;
    background: none;
    border: 1px solid var(--border);
    border-radius: 8px;
    width: 36px;
    height: 36px;
    font-size: 1.1rem;
    cursor: pointer;
    color: var(--text);
    display: flex;
    align-items: center;
    justify-content: center;
}

.post-close:hover {
    background: var(--bg-alt);
}

.post-modal h2 {
    font-size: 1.5rem;
    margin-bottom: 8px;
    padding-right: 40px;
}

.post-meta {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 24px;
    color: var(--text-secondary);
    font-size: 0.9rem;
    flex-wrap: wrap;
}

.post-content {
    line-height: 1.8;
    color: var(--text);
    font-size: 1rem;
}

.post-content h2 {
    font-size: 1.35rem;
    margin: 28px 0 12px;
}

.post-content h3 {
    font-size: 1.15rem;
    margin: 24px 0 10px;
}

.post-content p {
    margin-bottom: 16px;
}

.post-content ul, .post-content ol {
    margin-bottom: 16px;
    padding-left: 24px;
}

.post-content li {
    margin-bottom: 6px;
}

.post-content code {
    background: var(--bg-alt);
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.9em;
}

.post-content pre {
    background: var(--bg-alt);
    padding: 16px;
    border-radius: 8px;
    overflow-x: auto;
    margin-bottom: 16px;
}

.post-content pre code {
    background: none;
    padding: 0;
}

.post-content table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 16px;
}

.post-content th, .post-content td {
    border: 1px solid var(--border);
    padding: 8px 12px;
    text-align: left;
}

.post-content th {
    background: var(--bg-alt);
}

footer {
    text-align: center;
    padding: 32px 0;
    border-top: 1px solid var(--border);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

@media (max-width: 640px) {
    .hero h1 { font-size: 2rem; }
    .section-title { font-size: 1.5rem; }
    .blog-grid { grid-template-columns: 1fr; }
    .about-content { flex-direction: column; text-align: center; }
    .skills { justify-content: center; }

    .menu-toggle { display: block; }
    .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--bg);
        border-bottom: 1px solid var(--border);
        padding: 16px 24px;
        gap: 16px;
    }
    .nav-links.open { display: flex; }
}