:root {
    --color-bci: #22d3ee; /* cyan-400 */
    --color-ge: #facc15;  /* amber-400 */
    --color-bci-dark: #0e7490;
    --color-ge-dark: #b45309;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: #111827; /* gray-900 */
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Inter', sans-serif;
}

code, pre {
    font-family: 'Source Code Pro', monospace;
}

/* Animations for header */
@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-fade-in-down {
    animation: fadeInDown 1s ease-out forwards;
}

.animate-fade-in-up {
    animation: fadeInUp 1s ease-out forwards;
}


/* Timeline Styles */
#timeline-container {
    position: relative;
    padding: 2rem 0;
}

#timeline-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 3px;
    height: 100%;
    background: linear-gradient(to bottom, transparent, #4b5563, transparent);
}

.timeline-item {
    padding: 1rem 2rem;
    position: relative;
    margin: 1rem 0;
    width: 50%;
    opacity: 0;
    transform: translateY(50px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.timeline-item.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.timeline-item:nth-child(odd) {
    left: 0;
    padding-left: 3rem;
    text-align: right;
}

.timeline-item:nth-child(even) {
    left: 50%;
    padding-right: 3rem;
    text-align: left;
}

.timeline-item-content {
    padding: 1.5rem;
    border-radius: 0.5rem;
    position: relative;
    background-color: rgba(31, 41, 55, 0.5); /* gray-800 with transparency */
    backdrop-filter: blur(10px);
    border: 1px solid rgba(55, 65, 81, 0.5);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.timeline-item-content:hover {
    transform: translateY(-5px);
}

.timeline-item-content::before {
    content: '';
    position: absolute;
    top: 24px;
    width: 0;
    height: 0;
    border: 7px solid transparent;
}

.timeline-item:nth-child(odd) .timeline-item-content::before {
    right: -14px;
    border-left-color: #374151; /* gray-700 */
}

.timeline-item:nth-child(even) .timeline-item-content::before {
    left: -14px;
    border-right-color: #374151; /* gray-700 */
}

.timeline-icon {
    position: absolute;
    top: 20px;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
    border: 3px solid;
    background-color: #111827;
}

.timeline-item:nth-child(odd) .timeline-icon {
    right: -20px;
    transform: translateX(50%);
}

.timeline-item:nth-child(even) .timeline-icon {
    left: -20px;
    transform: translateX(-50%);
}

.timeline-item-content h3 {
    margin-top: 0;
    font-weight: 900;
    font-size: 1.5rem;
    letter-spacing: -0.05em;
}

.timeline-item-content .year {
    font-family: 'Source Code Pro', monospace;
    font-size: 0.9rem;
    font-weight: 600;
    padding: 0.25rem 0.5rem;
    border-radius: 9999px;
    display: inline-block;
    margin-bottom: 0.75rem;
}

.timeline-item-content p {
    font-size: 0.95rem;
    line-height: 1.6;
    color: #d1d5db; /* gray-300 */
}

/* Color Coding */
.bci .timeline-icon {
    border-color: var(--color-bci);
    color: var(--color-bci);
}
.bci .timeline-item-content {
    box-shadow: 0 0 15px rgba(34, 211, 238, 0.1);
}
.bci .timeline-item-content:hover {
    box-shadow: 0 0 25px rgba(34, 211, 238, 0.2);
}
.bci .year {
    background-color: var(--color-bci-dark);
    color: white;
}
.bci h3 { color: var(--color-bci); }

.ge .timeline-icon {
    border-color: var(--color-ge);
    color: var(--color-ge);
}
.ge .timeline-item-content {
    box-shadow: 0 0 15px rgba(250, 204, 21, 0.1);
}
.ge .timeline-item-content:hover {
    box-shadow: 0 0 25px rgba(250, 204, 21, 0.2);
}
.ge .year {
    background-color: var(--color-ge-dark);
    color: white;
}
.ge h3 { color: var(--color-ge); }


/* Responsive Styles */
@media screen and (max-width: 768px) {
    #timeline-container::before {
        left: 20px;
        transform: translateX(0);
    }
    
    .timeline-item,
    .timeline-item:nth-child(even) {
        width: 100%;
        left: 0;
        padding-left: 60px;
        padding-right: 15px;
        text-align: left;
    }

    .timeline-item:nth-child(odd) {
        padding-left: 60px;
    }

    .timeline-item:nth-child(odd) .timeline-icon,
    .timeline-item:nth-child(even) .timeline-icon {
        left: 20px;
        transform: translateX(-50%);
    }

    .timeline-item:nth-child(odd) .timeline-item-content::before,
    .timeline-item:nth-child(even) .timeline-item-content::before {
        left: -14px;
        border-right-color: #374151;
        border-left-color: transparent;
    }
}