:root {
    --bg: #f8f9fa;
    --surface: #ffffff;
    --primary: #1a73e8;
    --text: #202124;
    --muted: #5f6368;
    --border: #e0e0e0;
    --radius: 12px;
    --shadow: 0 1px 3px rgba(0, 0, 0, .12), 0 1px 2px rgba(0, 0, 0, .08);
}

body {
    font-family: var(--font-stack);
    color: var(--text);
}

header,
main,
footer {
    max-width: 980px;
    margin: 0 auto;
    padding: 24px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

h1,
h2,
h3,
h4 {
    font-family: var(--font-heading);
    color: var(--color-heading);
}

a {
    color: var(--color-primary);
}

.btn {
    background: var(--color-primary);
    color: #fff;
}

.btn.secondary {
    background: var(--color-secondary);
}