:root {
    /* Fonts */
    --font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    
    /* Colors - Light Mode (Default variables, will be overridden by dark mode) */
    --bg-color: #FFFFFF;
    --text-color: #525252;
    --heading-color: #000000;
    --accent-color: #DC2626; /* Red */
    
    --toggle-bg: #FFFFFF;
    --toggle-border: #E5E5E5;
    --toggle-icon: #171717;
    --toggle-hover-border: #DC2626;
}

[data-theme="dark"] {
    --bg-color: #000000; /* As per summary, or #171717 if we want slightly lighter than pure black */
    --text-color: #A3A3A3;
    --heading-color: #FFFFFF;
    
    --toggle-bg: #171717;
    --toggle-border: #404040;
    --toggle-icon: #F5F5F5;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    z-index: 50;
}

/* Navigation Buttons (Home & Theme Toggle) */
.nav-button {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--toggle-bg);
    border: 1px solid var(--toggle-border);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: border-color 0.3s ease;
    /* Ensure icon color inheritance */
    color: var(--toggle-icon);
}

.nav-button:hover {
    border-color: var(--toggle-hover-border);
}

.icon {
    width: 20px;
    height: 20px;
    color: var(--toggle-icon);
}

/* Hide/Show logic for icons */
#sun-icon { display: none; }
#moon-icon { display: block; }

[data-theme="dark"] #sun-icon { display: block; }
[data-theme="dark"] #moon-icon { display: none; }


/* Main Content */
.main-content {
    flex-grow: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.page-title {
    font-size: 3rem; /* Fallback */
    font-size: clamp(3rem, 10vw, 6rem);
    font-weight: 900;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: -0.05em;
    line-height: 0.9;
    color: var(--heading-color);
}

.highlight {
    color: var(--accent-color);
}

.mt-8 {
    margin-top: 2rem;
}

.action-button {
    display: inline-block;
    padding: 0.75rem 2rem;
    border-radius: 9999px;
    border: 1px solid var(--toggle-border);
    color: var(--text-color);
    text-decoration: none;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    font-size: 0.875rem;
    font-weight: 700;
    transition: all 0.3s ease;
}

[data-theme="dark"] .action-button {
    border-color: var(--toggle-border);
    color: var(--text-color);
}

.action-button:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
}