:root {
    --bg-color: #fafafa;
    --text-primary: #111111;
    --text-secondary: #666666;
    --border-color: #eaeaeb;
    --hover-bg: #f0f0f0;
    --accent-color: #000000;
    --gradient-start: #ff7e5f;
    --gradient-end: #feb47b;
}

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

*,
*::before,
*::after {
    box-sizing: inherit;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Navigation */
.top-nav {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: rgba(250, 250, 250, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.nav-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    font-weight: 700;
    font-size: 1.8rem;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: -0.04em;
}

.logo-img {
    height: 40px;
    width: auto;
    margin-right: 12px;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 1.1rem;
    font-weight: 500;
    transition: color 0.2s ease;
}

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

/* Layout */
.content-container {
    max-width: 800px;
    margin: 100px auto 0;
    padding: 2rem;
    min-height: calc(100vh - 160px);
}

/* Sections (SPA feel) */
.page-section {
    display: none;
    animation: fadeIn 0.4s ease-out;
}

.page-section.active-section {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Hero Section */
.hero {
    margin-top: 2rem;
    margin-bottom: 4rem;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 3rem;
    letter-spacing: -0.02em;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 1rem;
    display: inline-block;
}

.gradient-text {
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-bio {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 650px;
    margin-bottom: 2.5rem;
    line-height: 1.7;
}

/* Buttons / Links */
.social-links {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.social-btn {
    display: inline-block;
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.2s ease;
    background: transparent;
}

.social-btn:hover:not(.disabled) {
    background: var(--hover-bg);
    border-color: #444;
}

.social-btn.disabled {
    opacity: 0.5;
    cursor: not-allowed;
    border-style: dashed;
}

/* Cards (for posts/education content) */
/* Blog Feed */
.post-list {
    display: flex;
    flex-direction: column;
    gap: 3rem;
}

.post-item {
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 2rem;
}

.post-meta {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.post-title {
    font-size: 1.6rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.post-title a {
    color: var(--text-primary);
    text-decoration: none;
}

.post-title a:hover {
    text-decoration: underline;
}

.post-excerpt {
    font-size: 1.05rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.read-more {
    font-weight: 500;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.95rem;
}

.read-more:hover {
    text-decoration: underline;
}

.tags {
    margin-top: 1rem;
    display: flex;
    gap: 0.5rem;
}

.comments-section {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px dashed var(--border-color);
}

.card {
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: transparent;
    transition: border-color 0.2s ease, transform 0.2s ease;
}

.card:hover {
    border-color: #444;
    transform: translateY(-2px);
}

.card h3 {
    font-size: 1.2rem;
    font-weight: 500;
    margin-top: 0;
    margin-bottom: 0.5rem;
}

.card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

.card-tag {
    display: inline-block;
    font-size: 0.75rem;
    padding: 0.2rem 0.5rem;
    background: var(--hover-bg);
    border-radius: 4px;
    color: var(--text-secondary);
}

/* Global Headers */
.section-header {
    margin-bottom: 2rem;
}

.section-header h2 {
    font-size: 1.8rem;
    font-weight: 500;
    letter-spacing: -0.03em;
    margin-bottom: 0.5rem;
}

.section-header p {
    color: var(--text-secondary);
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
    font-size: 0.85rem;
    border-top: 1px solid var(--border-color);
    max-width: 800px;
    margin: 0 auto;
}

/* Responsive */
@media (max-width: 600px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }

    .hero-title {
        font-size: 2.2rem;
    }

    .content-container {
        padding: 1rem;
        margin-top: 120px;
    }
}