:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    padding-top: 56px;
}

.hero-section {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 7rem 0 5rem;
    margin-top: -56px;
}

.skill-badge {
    margin: 0.2rem;
    background-color: var(--secondary-color);
    color: white;
}

.project-card {
    transition: transform 0.3s, box-shadow 0.3s;
    margin-bottom: 1.5rem;
    border: none;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 50px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--secondary-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 30px;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -40px;
    top: 5px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    border: 3px solid var(--secondary-color);
}

.timeline-content {
    padding: 20px;
    background: white;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

/* Section padding */
section {
    padding: 5rem 0;
}

/* Navbar active state */
.navbar-dark .navbar-nav .nav-link.active {
    color: var(--secondary-color);
    font-weight: bold;
}

/* Smooth scroll */
html {
    scroll-behavior: smooth;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .hero-section {
        padding: 6rem 0 4rem;
    }
    
    section {
        padding: 3rem 0;
    }
    
    .timeline {
        padding-left: 30px;
    }
    
    .timeline-item::before {
        left: -30px;
    }
}

/* Toast notifications */
.toast {
    transition: opacity 0.3s ease;
}

.toast-container {
    z-index: 1100;
}

/* Spinner for buttons */
.btn .spinner-border {
    margin-right: 0.5rem;
}

/* Disabled button state */
.btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}