:root {
    --primary: #38bdf8; /* Light Blue */
    --secondary: #94a3b8; /* Grey Text */
    --bg-dark: #0f172a; /* Deep Slate */
    --bg-card: #1e293b; /* Lighter Slate */
    --text-light: #f8fafc;
    --accent: #0ea5e9;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-light);
    line-height: 1.6;
}

a { text-decoration: none; color: inherit; transition: 0.3s; }
ul { list-style: none; }

/* Utilities */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

.section { padding: 80px 0; }
.bg-alt { background-color: #162032; }

.section-title {
    font-size: 2rem;
    margin-bottom: 40px;
    text-align: center;
    color: var(--primary);
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    padding: 20px 0;
    z-index: 1000;
    border-bottom: 1px solid rgba(255,255,255,0.05);
}

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

.logo { font-size: 1.5rem; font-weight: 700; color: var(--text-light); }

.nav-links { display: flex; gap: 30px; align-items: center; }
.nav-links a:hover { color: var(--primary); }

.btn-primary {
    background: var(--primary);
    color: var(--bg-dark);
    padding: 10px 25px;
    border-radius: 5px;
    font-weight: 600;
}
.btn-primary:hover { background: var(--accent); color: white; }

/* Hero */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding-top: 60px;
}

.greeting { color: var(--primary); font-size: 1.2rem; font-weight: 600; }
.hero h1 { font-size: 3.5rem; margin: 10px 0; }
.subtitle { font-size: 1.5rem; color: var(--secondary); margin-bottom: 20px; }
.description { max-width: 600px; margin: 0 auto 30px; color: var(--secondary); }

.social-links a {
    font-size: 1.8rem;
    margin: 0 15px;
    color: var(--secondary);
}
.social-links a:hover { color: var(--primary); transform: translateY(-3px); display: inline-block; }

/* Cards & Education */
.card {
    background: var(--bg-card);
    padding: 30px;
    border-radius: 12px;
    border: 1px solid rgba(255,255,255,0.05);
    margin-bottom: 20px;
}

.card-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px; }
.card-header h3 { font-size: 1.4rem; }
.date { color: var(--secondary); font-size: 0.9rem; }
.role { color: var(--primary); font-weight: 600; margin-bottom: 5px; }

.honors-box {
    display: flex;
    align-items: center;
    background: linear-gradient(45deg, #1e293b, #0f172a);
    padding: 20px;
    border-radius: 10px;
    border: 1px solid var(--primary);
    gap: 20px;
}
.honors-box i { font-size: 2rem; color: #fbbf24; }

/* Timeline (Research) */
.timeline-item {
    background: var(--bg-card);
    padding: 30px;
    border-radius: 12px;
    margin-bottom: 25px;
    position: relative;
    border-left: 4px solid var(--primary);
}

.timeline-content h3 { margin-bottom: 5px; }
.supervisor { display: block; color: var(--secondary); font-style: italic; font-size: 0.9rem; margin-bottom: 15px; }
.timeline-content ul { padding-left: 20px; list-style-type: disc; color: #cbd5e1; }

/* Teaching Grid */
.grid-4 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}
.skill-card {
    background: var(--bg-card);
    padding: 25px;
    text-align: center;
    border-radius: 10px;
    transition: 0.3s;
}
.skill-card:hover { transform: translateY(-5px); background: #253346; }
.skill-card i { display: block; font-size: 2rem; color: var(--primary); margin-bottom: 15px; }

/* Skills Tags */
.skills-wrapper { display: flex; flex-direction: column; gap: 30px; }
.skill-category h3 { margin-bottom: 15px; color: var(--secondary); border-bottom: 1px solid #334155; padding-bottom: 5px; display: inline-block;}
.tags { display: flex; flex-wrap: wrap; gap: 10px; }
.tags span {
    background: rgba(56, 189, 248, 0.1);
    color: var(--primary);
    padding: 8px 16px;
    border-radius: 50px;
    font-size: 0.9rem;
    border: 1px solid rgba(56, 189, 248, 0.2);
}

/* Footer */
footer { text-align: center; padding: 80px 0 40px; }
footer h2 { margin-bottom: 15px; }
footer p { color: var(--secondary); margin-bottom: 30px; }
.footer-bottom { margin-top: 50px; font-size: 0.8rem; opacity: 0.5; }

/* Mobile Responsive */
.hamburger { display: none; cursor: pointer; font-size: 1.5rem; }

@media (max-width: 768px) {
    .nav-links { display: none; }
    .hamburger { display: block; }
    .hero h1 { font-size: 2.5rem; }
    .card-header { flex-direction: column; align-items: flex-start; }
}