/* -------------------- Reset & Base -------------------- */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --nav-bg: #ffffff;
    --text-color: #222222;
    --accent-color: #1e90ff;
    --accent-hover: #187bcd;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: #f9f9f9;
    padding: 20px;
}

/* -------------------- Navigation -------------------- */
.top-nav {
    background-color: var(--nav-bg);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    padding: 1rem;
}

.nav-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 960px;
    margin: 0 auto;
    padding: 0.5rem 1rem;
    position: relative;
}

.nav-menu {
    display: flex;
    align-items: center;
    list-style: none;
    margin: 0;
    padding: 0;
    flex-wrap: nowrap;
    width: 100%;
    justify-content: space-between;
}

.nav-menu li {
    display: flex;
    align-items: center;
}

.home-link {
    background-color: black;
    color: white;
    padding: 0.4rem 0.8rem;
    border-radius: 4px;
    font-weight: 600;
    text-decoration: none;
    font-size: 1rem;
    white-space: nowrap;
}

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

/* -------------------- Theme Toggle Button -------------------- */
.toggle-btn {
    background-color: var(--accent-color);
    color: white;
    border: none;
    border-radius: 5px;
    padding: 0.3rem 0.6rem;
    font-size: 0.9rem;
    cursor: pointer;
    transition: background-color 0.3s ease;
    margin-left: auto;
}

.toggle-btn:hover {
    background-color: var(--accent-hover);
}

/* -------------------- Main Layout -------------------- */
main {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem;
    text-align: center;
}

.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 2rem;
}

section {
    margin-bottom: 2rem;
    text-align: center;
}

.hero-photo {
    width: 160px;
    height: 160px;
    border-radius: 50%;
    object-fit: cover;
    display: block;
    margin: 0 auto 1rem;
}

/* -------------------- Projects Grid -------------------- */
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.project-card {
    background-color: white;
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 1rem;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
    transition: transform 0.2s ease-in-out;
}

.project-card:hover {
    transform: scale(1.02);
}

.btn {
    display: inline-block;
    margin-top: 0.5rem;
    padding: 0.5rem 1rem;
    background-color: #24292e;
    color: #fff;
    text-decoration: none;
    border-radius: 4px;
    transition: background-color 0.3s ease;
}

.btn:hover {
    background-color: #ff9800;
}

/* -------------------- Contact & Footer -------------------- */
.social-links a {
    display: inline-block;
    margin: 0.5rem;
    color: #24292e;
    text-decoration: none;
}

.social-links a:hover {
    color: #ff9800;
}

footer {
    margin-top: 3rem;
    text-align: center;
    color: #666;
}

/* -------------------- Responsive -------------------- */
@media (max-width: 768px) {
    .nav-menu {
        flex-direction: row;
        justify-content: space-between;
    }

    .toggle-btn {
        font-size: 0.85rem;
        padding: 0.25rem 0.5rem;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .project-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* -------------------- Dark Mode -------------------- */
body.dark-mode {
    background-color: #121212;
    color: #f1f1f1;
}

body.dark-mode .top-nav {
    background-color: #1f1f1f;
}

body.dark-mode .nav-menu li a,
body.dark-mode .social-links a {
    color: #f1f1f1;
}

body.dark-mode .btn {
    background-color: #333;
}

body.dark-mode .btn:hover {
    background-color: #ff9800;
}

body.dark-mode .project-card {
    background-color: #1e1e1e;
    border-color: #444;
}

body.dark-mode footer {
    color: #aaa;
}