* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    scrollbar-width: none;
}

:root {
    --primary: #A63A32;
    --primary-alt: #8B2F28;
    --bg-body: #FAFAFA;
    --bg-card: #FFFFFF;
    --bg-hover: #F0F0F0;
    --bg-subtle: #F1F1F1;
    --text-primary: #17181A;
    --text-secondary: #53565A;
    --text-muted: #8B8E92;
    --border-color: rgba(0, 0, 0, 0.1);
    --border-hover: rgba(0, 0, 0, 0.25);
    --shadow-color: rgba(0, 0, 0, 0.08);
    --header-bg: rgba(250, 250, 250, 0.85);
}

[data-theme="dark"] {
    --primary: #D9564C;
    --primary-alt: #C0453C;
    --bg-body: #101112;
    --bg-card: #191A1B;
    --bg-hover: #212223;
    --bg-subtle: #1C1D1E;
    --text-primary: #F2F2F2;
    --text-secondary: #B4B6B8;
    --text-muted: #7A7C7F;
    --border-color: rgba(255, 255, 255, 0.1);
    --border-hover: rgba(255, 255, 255, 0.25);
    --shadow-color: rgba(0, 0, 0, 0.4);
    --header-bg: rgba(16, 17, 18, 0.85);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-body);
    color: var(--text-primary);
    min-height: 100vh;
    transition: background-color 0.3s ease, color 0.3s ease;
}

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

/* Scrolling stays functional everywhere; the scrollbar itself is just hidden. */
::-webkit-scrollbar {
    display: none;
}

.mono {
    font-family: 'Roboto Mono', monospace;
}

/* Two-column layout: fixed sidebar (truly static, never scrolls with the page)
   + scrollable content column. The sidebar is taken out of flow via
   `position: fixed` rather than `sticky` because `sticky` only holds while its
   containing block (.page-layout) still has room below it — since
   .page-layout's height matches the much-taller content column, the sidebar
   would unstick and scroll away in the final stretch of the page (right where
   the footer is). Fixed positioning has no such containing-block limit. */
.page-layout {
    max-width: 1240px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

.sidebar {
    position: fixed;
    top: 4rem;
    left: max(2rem, calc((100vw - 1240px) / 2 + 2rem));
    width: 320px;
    max-height: calc(100vh - 6rem);
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 1.75rem;
}

main.content-column {
    position: relative;
    min-width: 0;
    margin-left: calc(320px + 3.5rem);
}

/* Sections */
section {
    margin-bottom: 6rem;
    animation: fadeInUp 0.5s ease-out;
    scroll-margin-top: 100px;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(14px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section-title {
    font-size: 1.9rem;
    margin-bottom: 2.5rem;
    color: var(--text-primary);
    font-weight: 800;
    letter-spacing: -0.02em;
}

.btn {
    padding: 0.9rem 1.7rem;
    border: none;
    border-radius: 999px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all 0.25s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    text-decoration: none;
    font-family: 'Inter', sans-serif;
}

.btn i {
    transition: transform 0.25s ease;
}

.btn:hover i {
    transform: translateX(3px);
}

.btn-primary {
    background: var(--text-primary);
    color: var(--bg-body);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 24px var(--shadow-color);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-hover);
    border-color: var(--border-hover);
    transform: translateY(-2px);
}