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

:root {
    --bg: #f8f9fa;
    --bg-card: #ffffff;
    --bg-hero: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    --text: #212529;
    --text-light: #6c757d;
    --text-muted: #adb5bd;
    --accent: #4361ee;
    --accent-hover: #3a56d4;
    --border: #e9ecef;
    --shadow: 0 2px 15px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 8px 30px rgba(0, 0, 0, 0.12);
    --radius: 12px;
    --max-width: 1000px;
    --ls: 0.08em;
    --ls-wide: 0.15em;
}

body {
    font-family: "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.8;
    font-weight: 400;
    letter-spacing: var(--ls);
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 32px;
}

/* Header */
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
}

header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    font-size: 1.3rem;
    font-weight: 500;
    letter-spacing: var(--ls-wide);
    color: var(--text);
}

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

nav {
    display: flex;
    gap: 32px;
}

nav a {
    color: var(--text-light);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    letter-spacing: var(--ls-wide);
    transition: color 0.3s;
}

nav a:hover {
    color: var(--text);
}

/* Hero */
.hero {
    padding: 160px 0 100px;
    background: var(--bg-hero);
    color: #ffffff;
    margin-bottom: 60px;
}

.hero h1 {
    font-size: clamp(2.2rem, 5vw, 3.2rem);
    font-weight: 500;
    line-height: 1.1;
    letter-spacing: var(--ls-wide);
    margin-bottom: 24px;
}

.hero .accent {
    color: #a5b4fc;
}

.subtitle {
    font-size: 1.1rem;
    font-weight: 400;
    color: rgba(255, 255, 255, 0.75);
    max-width: 560px;
    line-height: 1.8;
    letter-spacing: var(--ls);
}

/* Tech Stack */
.tech-stack {
    padding: 0 0 60px;
}

.tech-stack .container {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}

.tech-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 20px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 999px;
    font-size: 0.9rem;
    font-weight: 400;
    color: var(--text-light);
    letter-spacing: var(--ls);
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
}

.tech-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.tech-icon {
    width: 34px;
    height: 34px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.75rem;
    letter-spacing: 0;
    background: #eef2ff;
    color: var(--accent);
}

/* Articles */
.articles {
    padding: 20px 0 80px;
}

.articles h2 {
    font-size: 1.6rem;
    font-weight: 500;
    letter-spacing: var(--ls-wide);
    margin-bottom: 40px;
    color: var(--text);
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 40px;
    margin-bottom: 24px;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.card-tag {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    background: #e0f2fe;
    color: #0284c7;
    margin-bottom: 16px;
}

.tag-node {
    background: #dcfce7;
    color: #16a34a;
}

.tag-react {
    background: #e0f2fe;
    color: #0ea5e9;
}

.card h3 {
    font-size: 1.3rem;
    font-weight: 500;
    letter-spacing: var(--ls);
    margin-bottom: 8px;
    color: var(--text);
}

.card-meta {
    font-size: 0.85rem;
    font-weight: 400;
    color: var(--text-muted);
    letter-spacing: var(--ls);
    margin-bottom: 24px;
}

.card-body p {
    margin-bottom: 16px;
    color: var(--text-light);
    font-size: 0.95rem;
    font-weight: 400;
    line-height: 1.8;
}

.card-body h4 {
    font-size: 1.05rem;
    font-weight: 500;
    letter-spacing: var(--ls);
    margin: 28px 0 14px;
    color: var(--text);
}

.card-body ul {
    margin: 0 0 16px 24px;
    color: var(--text-light);
    font-size: 0.95rem;
    font-weight: 400;
}

.card-body li {
    margin-bottom: 10px;
    line-height: 1.7;
}

.card-body code {
    background: #f1f5f9;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.85em;
    color: var(--accent);
    font-family: "SF Mono", "Fira Code", "Cascadia Code", "Consolas", monospace;
    letter-spacing: 0;
}

/* About */
.about {
    padding: 60px 0 80px;
    border-top: 1px solid var(--border);
}

.about h2 {
    font-size: 1.6rem;
    font-weight: 500;
    letter-spacing: var(--ls-wide);
    margin-bottom: 24px;
}

.about-content p {
    color: var(--text-light);
    font-size: 0.95rem;
    font-weight: 400;
    margin-bottom: 14px;
    max-width: 640px;
    line-height: 1.8;
}

/* Footer */
footer {
    padding: 40px 0;
    background: #212529;
    color: var(--text-muted);
}

footer p {
    font-size: 0.85rem;
    font-weight: 400;
    letter-spacing: var(--ls);
}

/* Responsive */
@media (max-width: 640px) {
    .hero {
        padding: 120px 0 70px;
    }

    .card {
        padding: 28px;
    }

    .tech-stack .container {
        gap: 10px;
    }

    .tech-item {
        padding: 10px 16px;
        font-size: 0.85rem;
    }

    nav {
        gap: 18px;
    }

    nav a {
        font-size: 0.85rem;
    }
}