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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    line-height: 1.7;
    color: #222;
    background: #fff;
    padding: 2rem 1.5rem;
}

.container {
    max-width: 53rem;
    margin: 0 auto;
}

/* Navigation */
nav {
    margin-bottom: 2.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid #e0e0e0;
}

nav a {
    color: #222;
    text-decoration: none;
    margin-right: 1.5rem;
    font-size: 0.95rem;
}

nav a:hover {
    color: #0366d6;
}

nav a.active {
    color: #0366d6;
}

/* Typography */
h1 {
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 0.3rem;
    letter-spacing: -0.02em;
}

h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-top: 2.5rem;
    margin-bottom: 0.8rem;
}

h3 {
    font-size: 1.15rem;
    font-weight: 600;
    margin-top: 1.8rem;
    margin-bottom: 0.5rem;
}

p {
    margin-bottom: 1rem;
}

a {
    color: #0366d6;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* Homepage */
.tagline {
    font-size: 1.1rem;
    color: #555;
    margin-bottom: 1.5rem;
}

.profile-pic {
    width: 140px;
    height: auto;
    border-radius: 4px;
    margin-bottom: 1.5rem;
}

/* Lists */
ul {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

li {
    margin-bottom: 0.3rem;
}

/* Project image */
.project-img {
    max-width: 280px;
    height: auto;
    border-radius: 4px;
    margin: 0.5rem 0 1rem;
}

/* Video embed */
.video-container {
    position: relative;
    padding-bottom: 56.25%;
    margin: 1rem 0 1.5rem;
    max-width: 640px;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: 0;
}

/* Courses table */
.courses-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
    margin-bottom: 1.5rem;
}

.courses-table th,
.courses-table td {
    text-align: left;
    padding: 0.5rem 1rem;
    border-bottom: 1px solid #e0e0e0;
}

.courses-table th {
    font-weight: 600;
    white-space: nowrap;
    vertical-align: top;
}

.courses-table td {
    color: #444;
}

/* Responsive */
@media (max-width: 600px) {
    body {
        padding: 1.2rem 1rem;
    }

    h1 {
        font-size: 1.7rem;
    }

    nav a {
        margin-right: 1rem;
    }

    .courses-table th,
    .courses-table td {
        padding: 0.4rem 0.5rem;
        font-size: 0.9rem;
    }
}