:root {
    --bg-color: #0f172a;
    --surface-color: #1e293b;
    --primary-color: #38bdf8;
    --primary-hover: #0ea5e9;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --border-color: #334155;
    --card-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

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

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

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}

/* ==== Header & Nav ==== */
.site-header {
    background-color: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(8px);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

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

.logo a {
    font-size: 1.5rem;
    font-weight: 800;
    text-decoration: none;
    color: var(--primary-color);
    letter-spacing: -0.025em;
}

.main-nav ul {
    list-style: none;
    display: flex;
    gap: 2rem;
}

.main-nav a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.2s;
}

.main-nav a:hover, .main-nav a.active {
    color: var(--primary-color);
}

/* ==== Hero Section ==== */
.hero {
    padding: 8rem 0 4rem;
    text-align: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    background: linear-gradient(to right, #fff, var(--primary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto 2.5rem;
}

/* ==== Buttons ==== */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #0f172a;
}

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

.btn-secondary {
    background-color: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--surface-color);
    border-color: var(--primary-color);
}

/* ==== Skills Section ==== */
.skills-section {
    padding: 4rem 0;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 2rem;
    text-align: center;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1.5rem;
}

.skill-card {
    background-color: var(--surface-color);
    padding: 1.5rem;
    border-radius: 0.75rem;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: border-color 0.2s;
}

.skill-card:hover {
    border-color: var(--primary-color);
}

.skill-card i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    display: block;
}

/* ==== Cards & Grid ==== */
.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    padding: 2rem 0;
}

.card {
    background-color: var(--surface-color);
    border-radius: 1rem;
    overflow: hidden;
    text-decoration: none;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    transition: transform 0.3s, border-color 0.3s;
}

.card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-color);
}

.card-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-bottom: 1px solid var(--border-color);
}

.card-content {
    padding: 1.5rem;
}

.card-content h3 {
    margin-bottom: 0.75rem;
    font-size: 1.25rem;
}

.card-content p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ==== Content Styles (Blogs/Portfolios) ==== */
.article-header {
    text-align: center;
    margin-bottom: 3rem;
}

.article-title {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.article-meta {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

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

.article-content h2 {
    margin: 2rem 0 1rem;
    color: var(--primary-color);
}

.article-content p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

.article-content ul, .article-content ol {
    margin-bottom: 1.5rem;
    padding-left: 2rem;
}

.article-content li {
    margin-bottom: 0.5rem;
}

pre {
    background-color: var(--surface-color);
    padding: 1.5rem;
    border-radius: 0.5rem;
    overflow-x: auto;
    border: 1px solid var(--border-color);
    margin: 2rem 0;
}

code {
    font-family: 'Fira Code', 'Courier New', monospace;
    font-size: 0.9rem;
    color: #e2e8f0;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    margin-bottom: 2rem;
}

.back-link:hover {
    text-decoration: underline;
}

/* ==== Footer ==== */
.site-footer {
    padding: 4rem 0 2rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* ==== Mobile Nav ==== */
.mobile-nav-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .main-nav {
        display: none;
    }

    .mobile-nav-toggle {
        display: block;
    }

    .main-nav.nav-open {
        display: block;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--bg-color);
        padding: 1rem 0;
        border-bottom: 1px solid var(--border-color);
    }

    .main-nav.nav-open ul {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
    }
}

/* ==== Project Placeholders ==== */
.project-placeholder {
    background: var(--surface-color);
    height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    color: var(--primary-color);
}