:root {
    --bg-color: #0d1117;
    --bg-alt: #161b22;
    --card-bg: #1e242c;
    --text-main: #c9d1d9;
    --text-muted: #8b949e;
    --accent: #58a6ff;
    --border: #30363d;
    --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: var(--font-main);
    line-height: 1.6;
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 30px; }
.section { padding: 100px 0; }
.bg-alt { background-color: var(--bg-alt); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-title { font-size: 1.8rem; color: #fff; margin-bottom: 40px; border-left: 4px solid var(--accent); padding-left: 15px; }

/* Navbar */
.navbar { position: fixed; top: 0; width: 100%; background-color: rgba(13, 17, 23, 0.95); backdrop-filter: blur(5px); border-bottom: 1px solid var(--border); z-index: 1000; }
.nav-container { display: flex; justify-content: space-between; align-items: center; height: 70px; }
.logo { font-size: 1.2rem; font-weight: 700; color: #fff; letter-spacing: 1px; }

.main-nav { display: flex; gap: 25px; }
.main-nav a { color: var(--text-main); text-decoration: none; font-size: 0.95rem; font-weight: 500; transition: color 0.2s; }
.main-nav a:hover { color: var(--accent); }

.lang-switcher button { background: none; border: none; color: var(--text-muted); cursor: pointer; font-weight: bold; margin-left: 10px; transition: 0.2s; }
.lang-switcher button.active, .lang-switcher button:hover { color: var(--accent); }

/* Hero */
.hero { padding-top: 150px; padding-bottom: 80px; }
.hero h1 { font-size: 3.5rem; color: #fff; line-height: 1.2; margin-bottom: 10px; }
.hero h2 { font-size: 1.5rem; font-weight: 400; color: var(--text-muted); margin-bottom: 30px; }
.hero .summary { font-size: 1.15rem; max-width: 800px; margin-bottom: 40px; }

.tech-stack { display: flex; flex-wrap: wrap; gap: 10px; }
.tech-badge { background-color: transparent; border: 1px solid var(--border); color: var(--accent); padding: 6px 15px; border-radius: 20px; font-size: 0.9rem; font-weight: 600; }

/* Grid & Cards */
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 30px; }
.card { background-color: var(--card-bg); border: 1px solid var(--border); border-radius: 8px; padding: 25px; transition: transform 0.3s, border-color 0.3s; }
.card:hover { transform: translateY(-5px); border-color: var(--accent); }

.project-card h4, .blog-card h4 { color: #fff; font-size: 1.25rem; margin-bottom: 15px; }
.project-card p, .blog-card p { color: var(--text-muted); font-size: 0.95rem; margin-bottom: 20px; }

.card-tech { display: flex; gap: 10px; font-size: 0.8rem; color: var(--accent); }
.card-tech span { background: rgba(88, 166, 255, 0.1); padding: 3px 8px; border-radius: 4px; }

.post-date { display: block; font-size: 0.85rem; color: var(--text-muted); margin-bottom: 10px; }
.read-more { color: var(--accent); text-decoration: none; font-size: 0.9rem; font-weight: 600; }

/* Contact */
.contact-wrapper { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; }
.contact-info p { margin-bottom: 30px; }
.contact-links { list-style: none; }
.contact-links li { margin-bottom: 15px; display: flex; align-items: center; gap: 10px; }
.contact-links a { color: var(--text-main); text-decoration: none; transition: 0.2s; }
.contact-links a:hover { color: var(--accent); }

.contact-form .form-group { margin-bottom: 20px; }
.contact-form label { display: block; margin-bottom: 8px; font-size: 0.9rem; color: var(--text-muted); }
.contact-form input, .contact-form textarea { width: 100%; padding: 12px; background: var(--bg-color); border: 1px solid var(--border); border-radius: 6px; color: #fff; outline: none; font-family: inherit; }
.contact-form input:focus, .contact-form textarea:focus { border-color: var(--accent); }
.submit-btn { background-color: var(--accent); color: #000; border: none; padding: 12px 25px; font-weight: bold; border-radius: 6px; cursor: pointer; transition: 0.2s; width: 100%; font-size: 1rem; }
.submit-btn:hover { background-color: #3182ce; color: #fff; }

/* Article SPA View */
.article-container { max-width: 800px; padding-top: 120px; min-height: 80vh; }
.back-btn { background: transparent; border: 1px solid var(--border); color: var(--text-main); padding: 8px 16px; border-radius: 6px; cursor: pointer; font-size: 0.95rem; margin-bottom: 40px; transition: 0.2s; display: flex; align-items: center; gap: 8px; }
.back-btn:hover { background: var(--card-bg); color: var(--accent); border-color: var(--accent); }
.full-article h1 { font-size: 2.2rem; color: #fff; line-height: 1.3; margin-bottom: 30px; }
.article-body { font-size: 1.1rem; color: #c9d1d9; line-height: 1.8; }
.article-body p { margin-bottom: 25px; }
.article-body h3 { color: #fff; margin: 40px 0 15px 0; font-size: 1.3rem; }
.article-body ul { margin-bottom: 25px; padding-left: 20px; }
.article-body li { margin-bottom: 10px; }
.article-body code { background-color: rgba(110, 118, 129, 0.4); padding: 2px 6px; border-radius: 4px; font-family: monospace; font-size: 0.95rem; color: var(--accent); }

footer { padding: 40px 0; text-align: center; border-top: 1px solid var(--border); font-size: 0.9rem; color: var(--text-muted); }

/* Responsive */
@media (max-width: 850px) {
    .contact-wrapper { grid-template-columns: 1fr; gap: 40px; }
    .main-nav { display: none; }
    .hero h1 { font-size: 2.5rem; }
}