@font-face {
    font-family: 'iA Writer Quattro';
    src: url('fonts/iAWriterQuattroS-Regular.woff2') format('woff2');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'iA Writer Quattro';
    src: url('fonts/iAWriterQuattroS-Bold.woff2') format('woff2');
    font-weight: 700;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'iA Writer Mono';
    src: url('fonts/iAWriterMonoS-Regular.woff2') format('woff2');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}

:root {
    --bg: #0e0e0e;
    --bg-subtle: #141414;
    --text-primary: #b8b8b8;
    --text-secondary: #6b6b6b;
    --text-tertiary: #454545;
    --border: #1f1f1f;
    --code-bg: #161616;
}

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

html {
    font-size: 17px;
}

body {
    background-color: var(--bg);
    color: var(--text-primary);
    font-family: 'iA Writer Quattro', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.75;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

article {
    max-width: 680px;
    margin: 0 auto;
    padding: 6rem 2rem 8rem;
}

/* Fade in on load */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(12px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

header {
    margin-bottom: 5rem;
    padding-bottom: 4rem;
    border-bottom: 1px solid var(--border);
    animation: fadeIn 0.8s ease-out;
}

h1 {
    font-size: 1.5rem;
    font-weight: 400;
    letter-spacing: 0.25em;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.subtitle {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0.4rem;
    font-weight: 400;
}

.tagline {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.6;
}

.meta {
    font-size: 0.8rem;
    color: var(--text-tertiary);
    margin-bottom: 2.5rem;
    letter-spacing: 0.02em;
}

.download {
    display: inline-block;
    padding: 0.55rem 1.1rem;
    background: transparent;
    border: 1px solid var(--text-tertiary);
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.8rem;
    letter-spacing: 0.03em;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.download:hover {
    border-color: var(--text-secondary);
    color: var(--text-primary);
    transform: translateY(-1px);
}

section {
    margin-bottom: 3.5rem;
    animation: fadeIn 0.8s ease-out both;
}

section:nth-child(2) { animation-delay: 0.1s; }
section:nth-child(3) { animation-delay: 0.15s; }
section:nth-child(4) { animation-delay: 0.2s; }
section:nth-child(5) { animation-delay: 0.25s; }
section:nth-child(6) { animation-delay: 0.3s; }

h2 {
    font-size: 0.75rem;
    font-weight: 400;
    color: var(--text-tertiary);
    margin-bottom: 1.5rem;
    margin-top: 4rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

section:first-of-type h2 {
    margin-top: 0;
}

h3 {
    font-size: 0.95rem;
    font-weight: 400;
    color: var(--text-primary);
    margin-top: 2.5rem;
    margin-bottom: 1rem;
}

p {
    margin-bottom: 1.2rem;
    color: var(--text-primary);
}

em {
    font-style: italic;
    color: var(--text-primary);
}

strong {
    font-weight: 700;
    color: var(--text-primary);
}

a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.equation {
    font-family: 'iA Writer Mono', 'SF Mono', 'Monaco', monospace;
    font-size: 0.95rem;
    color: var(--text-primary);
    background: var(--code-bg);
    padding: 1.2rem 1.5rem;
    margin: 1.8rem 0;
    text-align: center;
    border-left: 1px solid var(--text-tertiary);
    transition: border-color 0.3s ease;
}

.equation:hover {
    border-color: var(--text-secondary);
}

code {
    font-family: 'iA Writer Mono', 'SF Mono', 'Monaco', monospace;
    font-size: 0.85em;
    background: var(--code-bg);
    padding: 0.15em 0.4em;
    border-radius: 2px;
    color: var(--text-secondary);
}

pre {
    background: var(--code-bg);
    padding: 1.5rem;
    overflow-x: auto;
    margin: 1.8rem 0;
    border-left: 1px solid var(--text-tertiary);
    transition: border-color 0.3s ease;
}

pre:hover {
    border-color: var(--text-secondary);
}

pre code {
    background: none;
    padding: 0;
    font-size: 0.8rem;
    line-height: 1.7;
    color: var(--text-primary);
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 2rem 0;
    font-size: 0.85rem;
}

th, td {
    text-align: left;
    padding: 0.9rem 1rem;
    border-bottom: 1px solid var(--border);
    transition: background 0.2s ease;
}

tr:hover td {
    background: var(--bg-subtle);
}

th {
    color: var(--text-tertiary);
    font-weight: 400;
    text-transform: uppercase;
    font-size: 0.7rem;
    letter-spacing: 0.08em;
}

td {
    color: var(--text-secondary);
}

td:first-child {
    font-family: 'iA Writer Mono', monospace;
    color: var(--text-primary);
}

tr:last-child td {
    border-bottom: none;
}

dl {
    margin: 1.5rem 0;
}

dt {
    font-weight: 400;
    color: var(--text-primary);
    margin-top: 1.8rem;
    font-size: 0.95rem;
}

dt:first-child {
    margin-top: 0;
}

dd {
    color: var(--text-secondary);
    margin-top: 0.3rem;
    padding-left: 0;
    font-size: 0.9rem;
}

footer {
    margin-top: 5rem;
    padding-top: 3rem;
    border-top: 1px solid var(--border);
    text-align: center;
    animation: fadeIn 0.8s ease-out 0.4s both;
}

footer a {
    color: var(--text-tertiary);
    text-decoration: none;
    font-size: 0.85rem;
    letter-spacing: 0.02em;
    transition: color 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

footer a:hover {
    color: var(--text-primary);
}

/* Selection */
::selection {
    background: rgba(184, 184, 184, 0.15);
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: var(--bg);
}

::-webkit-scrollbar-thumb {
    background: var(--text-tertiary);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

@media (max-width: 600px) {
    html {
        font-size: 15px;
    }
    
    article {
        padding: 3rem 1.25rem 5rem;
    }
    
    header {
        margin-bottom: 3rem;
        padding-bottom: 2.5rem;
    }
    
    h1 {
        font-size: 1.2rem;
        letter-spacing: 0.2em;
    }
    
    table {
        font-size: 0.75rem;
    }
    
    th, td {
        padding: 0.6rem 0.5rem;
    }
}