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

body {
    font-family: var(--font-family-main);
    line-height: var(--line-height-base);
    color: var(--main-text-color);
    background-color: var(--background-color);
}

/* Fixed Top Bar */
.top-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--top-bar-color);
    color: white;
    padding: var(--spacing-sm) var(--spacing-md);
    z-index: var(--z-index-topbar);
    box-shadow: var(--shadow-light);
}

.top-bar-content {
    max-width: var(--content-max-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.top-bar-text {
    font-size: var(--font-size-large);
    font-weight: 300;
}

.top-bar-links {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.top-bar-links a {
    color: var(--top-bar-hyperlink-color);
    text-decoration: none;
    font-weight: 500;
    transition: opacity var(--transition-normal) var(--transition-ease);
}

.top-bar-links a:hover {
    opacity: var(--opacity-hover);
}

/* Main Content */
.main-content {
    margin-top: var(--top-bar-height);
    padding: var(--spacing-lg) var(--spacing-md) var(--spacing-md);
    max-width: var(--content-max-width);
    margin-left: auto;
    margin-right: auto;
}

/* Hero Section */
.hero-section {
    display: flex;
    align-items: center;
    gap: var(--hero-gap);
    margin-bottom: var(--spacing-xl);
    min-height: var(--hero-min-height);
}

.photo-container {
    flex: 0 0 var(--hero-photo-size);
    height: var(--hero-photo-size);
    background: var(--graph-bg-color);
    border-radius: var(--radius-large);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-body);
    color: var(--small-text-color);
    box-shadow: var(--shadow-heavy);
}

.hero-text {
    flex: 1;
    font-size: var(--font-size-large);
    line-height: var(--line-height-relaxed);
}

.hero-text .accent {
    color: var(--accent-text-color);
    font-weight: 600;
}

/* Projects Section */
.projects-section {
    margin: var(--spacing-xl) 0;
}

.section-title {
    font-size: var(--font-size-title);
    font-weight: 700;
    color: var(--accent-text-color);
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.projects-container {
    background: var(--graph-bg-color);
    border-radius: var(--radius-xl);
    padding: var(--graph-container-padding);
    text-align: center;
    color: var(--graph-text-color);
    min-height: var(--graph-container-min-height);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    position: relative;
    overflow: hidden;
}

/* Interactive Graph Styles */
#graph-container {
    width: 100%;
    height: 100%;
    min-height: 500px;
    position: relative;
    cursor: crosshair;
}

.graph-node {
    cursor: pointer;
    transition: all var(--transition-normal) var(--transition-ease);
}

.graph-node:hover .node-image {
    opacity: 1 !important;
    stroke-width: var(--graph-node-stroke-width-hover);
}

.graph-node:hover {
    filter: brightness(var(--hover-brightness));
}

.node-image {
    stroke: var(--graph-node-stroke);
    stroke-width: var(--graph-node-stroke-width);
    filter: drop-shadow(var(--shadow-graph-node));
}

.node-text {
    fill: var(--graph-text-color);
    font-size: var(--graph-text-size);
    font-weight: bold;
    text-anchor: middle;
    pointer-events: none;
}

.node-icon {
    fill: var(--graph-text-color);
    font-size: var(--graph-icon-size);
    text-anchor: middle;
    pointer-events: none;
}

.graph-link {
    stroke: var(--graph-link-color);
    stroke-width: var(--graph-link-width);
    stroke-opacity: var(--graph-link-opacity);
    filter: drop-shadow(var(--shadow-graph-link));
}

.graph-title {
    fill: var(--graph-text-color);
    font-size: var(--graph-title-size);
    font-weight: bold;
    text-anchor: middle;
    margin-bottom: var(--spacing-md);
}

.graph-description {
    color: var(--graph-text-secondary);
    font-size: var(--font-size-body);
    margin-bottom: var(--spacing-md);
    line-height: var(--line-height-base);
}

/* Footer */
.footer {
    text-align: center;
    padding: var(--spacing-md);
    color: var(--small-text-color);
    font-size: var(--font-size-small);
    border-top: 1px solid var(--small-text-color);
    margin-top: var(--spacing-xl);
}

/* Responsive Design */
@media (max-width: 768px) {
    .top-bar {
        padding: var(--spacing-sm) var(--spacing-sm);
    }

    .top-bar-content {
        flex-direction: column;
        gap: var(--spacing-xs);
    }

    .top-bar-links {
        gap: var(--spacing-sm);
    }

    .main-content {
        margin-top: var(--top-bar-mobile-height);
        padding: var(--spacing-md) var(--spacing-sm);
    }

    .hero-section {
        flex-direction: column;
        gap: var(--hero-gap-mobile);
        text-align: center;
    }

    .photo-container {
        flex: 0 0 var(--hero-photo-size-mobile);
        width: var(--hero-photo-size-mobile);
        height: var(--hero-photo-size-mobile);
    }

    .hero-text {
        font-size: var(--font-size-body);
    }

    .section-title {
        font-size: var(--font-size-title-mobile);
    }

    .projects-container {
        padding: var(--graph-container-padding-mobile);
        min-height: var(--graph-container-min-height-mobile);
    }

    #graph-container {
        min-height: 300px;
    }

    .node-image {
        stroke-width: var(--graph-node-stroke-width-mobile);
    }

    .node-text {
        font-size: var(--graph-text-size-mobile);
    }

    .node-icon {
        font-size: var(--graph-icon-size-mobile);
    }
}

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

/* Link styling */
a {
    color: var(--hyperlink-color);
    text-decoration: none;
    transition: all var(--transition-normal) var(--transition-ease);
}

a:hover {
    color: var(--accent-text-color);
    text-decoration: underline;
}