/* ─── Reset ─── */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    background: var(--bg-deep);
    color: var(--text-secondary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

/* ─── Ambient Background ─── */
.ambient-bg {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
}
.ambient-bg::before {
    content: '';
    position: absolute;
    top: -200px; left: 50%;
    transform: translateX(-50%);
    width: 800px; height: 800px;
    background: radial-gradient(circle, rgba(30, 64, 175, 0.15) 0%, transparent 70%);
    border-radius: 50%;
}
.ambient-bg::after {
    content: '';
    position: absolute;
    bottom: -300px; right: -200px;
    width: 600px; height: 600px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.08) 0%, transparent 70%);
    border-radius: 50%;
}

/* ─── Typography ─── */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary);
    line-height: 1.2;
    letter-spacing: -0.02em;
}

h1 { font-size: 48px; font-weight: 800; letter-spacing: -0.03em; }
h2 { font-size: 32px; font-weight: 700; }
h3 { font-size: 24px; font-weight: 600; }
h4 { font-size: 20px; font-weight: 600; }
h5 { font-size: 16px; font-weight: 600; }
h6 { font-size: 14px; font-weight: 600; }

p {
    color: var(--text-secondary);
    margin-bottom: 12px;
}

a {
    color: var(--blue-400);
    text-decoration: none;
    transition: color var(--transition);
}
a:hover {
    color: var(--blue-500);
}

strong, b {
    font-weight: 600;
    color: var(--text-primary);
}

code {
    font-family: 'Fira Code', 'SF Mono', 'Cascadia Code', monospace;
    background: rgba(59, 130, 246, 0.1);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-xs);
    padding: 2px 6px;
    font-size: 0.875em;
    color: var(--blue-400);
}

/* ─── Container ─── */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ─── Utility ─── */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ─── Scrollbar ─── */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-deep);
}
::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* Firefox */
* {
    scrollbar-width: thin;
    scrollbar-color: var(--border) var(--bg-deep);
}

/* ─── Selection ─── */
::selection {
    background: rgba(59, 130, 246, 0.3);
    color: var(--text-primary);
}

/* ─── Responsive Typography ─── */
@media (max-width: 768px) {
    h1 { font-size: 32px; }
    h2 { font-size: 24px; }
    h3 { font-size: 20px; }
}

@media (max-width: 480px) {
    h1 { font-size: 26px; }
    h2 { font-size: 20px; }
}