:root {
    --bg-color: #f8f9fa;
    --text-color: #121212;
    --card-bg: #ffffff;
    --border-color: #e0e0e0;
    --accent-color: #000000;
    --header-bg: rgba(248, 249, 250, 0.9);
}

[data-theme="dark"] {
    --bg-color: #121212;
    --text-color: #f8f9fa;
    --card-bg: #1e1e1e;
    --border-color: #333333;
    --accent-color: #ffffff;
    --header-bg: rgba(18, 18, 18, 0.9);
}

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

@keyframes subtlePageFade {
    0% {
        opacity: 0;
        background-color: var(--text-color); /* Flash inverse color */
    }
    100% {
        opacity: 1;
        background-color: var(--bg-color);
    }
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
    min-height: 100vh;
    
    /* Deliberate background fade effect on load */
    animation: subtlePageFade 0.6s cubic-bezier(0.25, 0.8, 0.25, 1) forwards;
}

/* Header */
.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: var(--header-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
}

.app-header h1 {
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: -0.02em;
}

#theme-toggle {
    background: none;
    border: none;
    color: var(--text-color);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s;
}

#theme-toggle:hover {
    background-color: rgba(128, 128, 128, 0.1);
}

.icon-sun, .icon-moon {
    display: none;
}

[data-theme="dark"] .icon-sun {
    display: block;
}
[data-theme="light"] .icon-moon,
:root:not([data-theme="dark"]) .icon-moon {
    display: block;
}

/* Container spacing */
.column-grid {
    padding: 2rem;
    max-width: 1400px;
    margin: 0 auto;
    
    display: flex;
    gap: 2rem;
    align-items: flex-start;
}

.grid-column {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 2rem;
    min-width: 0;
}

project-card {
    display: block;
    width: 100%;
}