:root {
    --primary-color: #ecf0f1;         /* Light text for dark backgrounds */
    --secondary-color: #3498db;
    --background-color: #181c22;      /* Dark background */
    --text-color: #ecf0f1;            /* Light text */
    --card-bg-color: #23272f;         /* Slightly lighter than background */
    --header-height: 70px;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--header-height);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
    background-color: var(--background-color);
    color: var(--text-color);
}

.container {
    max-width: 1100px;
    margin: auto;
    padding: 2rem;
    overflow: hidden;
}

header {
    background-color: #23272f;
    color: var(--primary-color);
    height: var(--header-height);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

header nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1100px;
    margin: auto;
    padding: 0 2rem;
    height: 100%;
}

header .logo {
    font-size: 1.5rem;
    font-weight: bold;
}

header ul {
    display: flex;
    list-style: none;
}

header ul li a {
    color: var(--primary-color);
    text-decoration: none;
    padding: 1rem;
    transition: background-color 0.3s ease;
}

header ul li a:hover {
    background-color: var(--secondary-color);
    color: #fff;
}

main {
    padding-top: var(--header-height);
}

section {
    background-color: transparent;
    padding: 4rem 2rem;
    border-bottom: 1px solid #ddd;
}

section:nth-of-type(even) {
    background-color: #23272f;
}

h1, h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.5rem; }

.btn {
    display: inline-block;
    background: var(--secondary-color);
    color: #fff;
    padding: 0.8rem 1.5rem;
    border-radius: 5px;
    text-decoration: none;
    margin-top: 1rem;
    transition: opacity 0.3s ease;
}

.btn:hover {
    opacity: 0.9;
}

/* Experience Section */
.job {
    background: var(--card-bg-color);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    color: var(--text-color);
}

.job h3 {
    color: var(--secondary-color);
}

.job-date {
    color: #b0b8c1;
    font-style: italic;
    margin-bottom: 0.5rem;
}

.job ul {
    margin-left: 20px;
}

/* Skills Section */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.skill {
    background: var(--card-bg-color);
    color: var(--text-color);
    padding: 1rem;
    text-align: center;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    font-weight: bold;
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.project-card {
    background: var(--card-bg-color);
    color: var(--text-color);
    border-radius: 5px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    display: flex;
    flex-direction: column;
    text-decoration: none;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.15);
}

.project-card-content {
    padding: 1.5rem;
    flex-grow: 1;
}

.project-card h3 {
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.project-card-footer {
    padding: 1rem 1.5rem;
    border-top: 1px solid #333a44;
    font-size: 0.9rem;
    color: #b0b8c1;
}

.project-card-placeholder {
    text-align: center;
    padding: 2rem;
    color: #b0b8c1;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem;
    background: #23272f;
    color: var(--primary-color);
}

/* Responsive */
@media (max-width: 768px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }

    header nav {
        flex-direction: column;
        height: auto;
        padding: 0.5rem 0;
    }
    
    header .logo {
        margin-bottom: 0.5rem;
    }

    header ul {
        flex-wrap: wrap;
        justify-content: center;
    }

    header ul li a {
        padding: 0.5rem 0.75rem;
    }

    main {
        padding-top: 110px; /* Adjust for taller header */
    }
}

section#projects {
    margin-bottom: 3rem;
}