/*
 * Pip Foweraker - Base Styles
 * Inspired by gwern.net's typography philosophy
 * Starting point for baroque/Elven/Parisian-deco evolution
 */

/* ==================== */
/* CSS CUSTOM PROPERTIES */
/* ==================== */

:root {
    /* Typography */
    --font-serif: "Source Serif 4", "Baskerville", "Libre Baskerville", "Times New Roman", serif;
    --font-sans: "Source Sans 3", "Helvetica Neue", "Helvetica", sans-serif;
    --font-mono: "IBM Plex Mono", "Consolas", "Monaco", monospace;

    --font-size-base: 20px;
    --font-size-small: 0.875em;
    --font-size-tiny: 0.75em;
    --line-height: 1.6;

    /* Layout */
    --content-max-width: 720px;
    --content-padding: 24px;
    --sidenote-width: 280px;
    --sidenote-gap: 30px;

    /* Colors - Light Mode */
    --color-bg: #fffcf7;
    --color-bg-alt: #f8f5f0;
    --color-text: #1a1a1a;
    --color-text-muted: #666;
    --color-text-faint: #999;
    --color-link: #2b4a6f;
    --color-link-hover: #1a2f47;
    --color-link-visited: #5c4a6f;
    --color-border: #d4d0c8;
    --color-border-light: #e8e4dc;
    --color-accent: #8b7355;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
}

/* Dark Mode */
@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #1a1a1a;
        --color-bg-alt: #242424;
        --color-text: #e8e4dc;
        --color-text-muted: #a8a4a0;
        --color-text-faint: #706c68;
        --color-link: #7ca4d4;
        --color-link-hover: #a8c8e8;
        --color-link-visited: #b8a4d4;
        --color-border: #3a3a3a;
        --color-border-light: #2e2e2e;
        --color-accent: #b89870;
    }
}

/* Manual dark mode toggle class */
.dark-mode {
    --color-bg: #1a1a1a;
    --color-bg-alt: #242424;
    --color-text: #e8e4dc;
    --color-text-muted: #a8a4a0;
    --color-text-faint: #706c68;
    --color-link: #7ca4d4;
    --color-link-hover: #a8c8e8;
    --color-link-visited: #b8a4d4;
    --color-border: #3a3a3a;
    --color-border-light: #2e2e2e;
    --color-accent: #b89870;
}

/* ==================== */
/* BASE RESET & LAYOUT  */
/* ==================== */

*, *::before, *::after {
    box-sizing: border-box;
}

html {
    font-size: var(--font-size-base);
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    margin: 0;
    padding: 0;
    background-color: var(--color-bg);
    color: var(--color-text);
    font-family: var(--font-serif);
    font-weight: 400;
    line-height: var(--line-height);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ==================== */
/* MAIN LAYOUT          */
/* ==================== */

.site-wrapper {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

main {
    flex: 1;
    width: 100%;
    max-width: calc(var(--content-max-width) + 2 * var(--content-padding));
    margin: 0 auto;
    padding: var(--space-lg) var(--content-padding);
}

/* Wide layout for sidenotes on large screens */
@media (min-width: 1100px) {
    main {
        max-width: calc(var(--content-max-width) + var(--sidenote-width) + var(--sidenote-gap) + 2 * var(--content-padding));
    }
}

article {
    max-width: var(--content-max-width);
}

/* ==================== */
/* TYPOGRAPHY           */
/* ==================== */

/* Headings */
h1, h2, h3, h4, h5, h6 {
    margin: var(--space-xl) 0 var(--space-md) 0;
    font-weight: 600;
    line-height: 1.25;
    letter-spacing: -0.02em;
}

h1 {
    font-size: 2.25em;
    margin-top: 0;
    font-variant-caps: small-caps;
    text-align: center;
}

h2 {
    font-size: 1.5em;
    border-bottom: 1px solid var(--color-border-light);
    padding-bottom: var(--space-sm);
}

h3 { font-size: 1.25em; }
h4 { font-size: 1.1em; }
h5, h6 { font-size: 1em; }

/* Paragraphs */
p {
    margin: 0 0 var(--space-md) 0;
}

/* First paragraph after heading - no extra spacing */
h1 + p, h2 + p, h3 + p, h4 + p {
    margin-top: 0;
}

/* Links */
a {
    color: var(--color-link);
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 2px;
    transition: color 0.15s ease;
}

a:hover {
    color: var(--color-link-hover);
}

a:visited {
    color: var(--color-link-visited);
}

/* Blockquotes */
blockquote {
    margin: var(--space-lg) 0;
    padding: var(--space-md) var(--space-lg);
    border-left: 3px solid var(--color-border);
    background: var(--color-bg-alt);
    font-style: italic;
}

blockquote p:last-child {
    margin-bottom: 0;
}

blockquote cite {
    display: block;
    margin-top: var(--space-sm);
    font-style: normal;
    font-size: var(--font-size-small);
    color: var(--color-text-muted);
}

/* Lists */
ul, ol {
    margin: 0 0 var(--space-md) 0;
    padding-left: var(--space-lg);
}

li {
    margin-bottom: var(--space-xs);
}

li > ul, li > ol {
    margin-top: var(--space-xs);
    margin-bottom: 0;
}

/* Code */
code {
    font-family: var(--font-mono);
    font-size: 0.9em;
    background: var(--color-bg-alt);
    padding: 0.1em 0.3em;
    border-radius: 3px;
}

pre {
    margin: var(--space-lg) 0;
    padding: var(--space-md);
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border-light);
    border-radius: 4px;
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: 0.875em;
    line-height: 1.5;
}

pre code {
    background: none;
    padding: 0;
}

/* Tables */
table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--space-md) 0 var(--space-lg) 0;
    font-size: var(--font-size-small);
}

thead {
    border-bottom: 2px solid var(--color-border);
}

th {
    text-align: left;
    padding: var(--space-sm) var(--space-md) var(--space-sm) 0;
    font-weight: 600;
    color: var(--color-text-muted);
    font-size: var(--font-size-tiny);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

td {
    padding: var(--space-sm) var(--space-md) var(--space-sm) 0;
    border-bottom: 1px solid var(--color-border-light);
    vertical-align: top;
}

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

/* Horizontal rules */
hr {
    border: none;
    border-top: 1px solid var(--color-border);
    margin: var(--space-xl) 0;
}

/* ==================== */
/* PAGE METADATA        */
/* ==================== */

.page-meta {
    margin: var(--space-md) 0 var(--space-xl) 0;
    padding: var(--space-md);
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border-light);
    font-size: var(--font-size-small);
    color: var(--color-text-muted);
    text-align: center;
}

.page-meta-item {
    display: inline-block;
    margin: 0 var(--space-md);
}

.page-meta-item::before {
    content: "";
}

.page-meta-label {
    font-weight: 600;
    text-transform: uppercase;
    font-size: var(--font-size-tiny);
    letter-spacing: 0.05em;
}

/* ==================== */
/* SIDENOTES            */
/* ==================== */

/* Container for sidenote-enabled content */
.has-sidenotes {
    position: relative;
}

/* Sidenote reference (the superscript number) */
.sidenote-ref {
    font-size: var(--font-size-tiny);
    vertical-align: super;
    line-height: 0;
    cursor: pointer;
    color: var(--color-accent);
}

.sidenote-ref::before {
    content: "[";
}
.sidenote-ref::after {
    content: "]";
}

/* Sidenote content */
.sidenote {
    font-size: var(--font-size-small);
    line-height: 1.4;
    color: var(--color-text-muted);
}

/* Mobile: sidenotes as inline notes */
@media (max-width: 1099px) {
    .sidenote {
        display: block;
        margin: var(--space-sm) 0 var(--space-md) var(--space-lg);
        padding: var(--space-sm) var(--space-md);
        background: var(--color-bg-alt);
        border-left: 2px solid var(--color-border);
    }
}

/* Desktop: sidenotes in margin */
@media (min-width: 1100px) {
    .sidenote {
        position: absolute;
        right: calc(-1 * (var(--sidenote-width) + var(--sidenote-gap)));
        width: var(--sidenote-width);
        margin-top: 0;
    }
}

/* ==================== */
/* FOOTNOTES (FALLBACK) */
/* ==================== */

.footnotes {
    margin-top: var(--space-xl);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border);
    font-size: var(--font-size-small);
}

.footnotes ol {
    padding-left: var(--space-lg);
}

.footnote-ref {
    font-size: var(--font-size-tiny);
    vertical-align: super;
    line-height: 0;
}

.footnote-backref {
    margin-left: var(--space-xs);
    text-decoration: none;
}

/* ==================== */
/* HEADER & NAVIGATION  */
/* ==================== */

.site-header {
    padding: var(--space-md) var(--content-padding);
    border-bottom: 1px solid var(--color-border-light);
}

.site-header-inner {
    max-width: var(--content-max-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-md);
}

.site-title {
    font-size: 1.25em;
    font-weight: 600;
    margin: 0;
}

.site-title a {
    color: var(--color-text);
    text-decoration: none;
}

.site-nav {
    display: flex;
    gap: var(--space-md);
    flex-wrap: wrap;
}

.site-nav a {
    color: var(--color-text-muted);
    text-decoration: none;
    font-size: var(--font-size-small);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 500;
}

.site-nav a:hover,
.site-nav a.active {
    color: var(--color-text);
}

/* ==================== */
/* FOOTER               */
/* ==================== */

.site-footer {
    margin-top: auto;
    padding: var(--space-lg) var(--content-padding);
    border-top: 1px solid var(--color-border-light);
    font-size: var(--font-size-small);
    color: var(--color-text-muted);
    text-align: center;
}

.site-footer a {
    color: var(--color-text-muted);
}

/* ==================== */
/* UTILITIES            */
/* ==================== */

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.text-center { text-align: center; }
.text-muted { color: var(--color-text-muted); }
.text-small { font-size: var(--font-size-small); }

/* ==================== */
/* RESPONSIVE           */
/* ==================== */

@media (max-width: 649px) {
    :root {
        --font-size-base: 18px;
        --content-padding: 16px;
    }

    h1 {
        font-size: 1.75em;
    }

    h2 {
        font-size: 1.35em;
    }
}

/* ==================== */
/* DARK MODE TOGGLE     */
/* ==================== */

.dark-mode-toggle {
    background: none;
    border: 1px solid var(--color-border);
    color: var(--color-text-muted);
    font-size: var(--font-size-small);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 500;
    padding: var(--space-xs) var(--space-sm);
    cursor: pointer;
    transition: all 0.15s ease;
    font-family: var(--font-sans);
}

.dark-mode-toggle:hover {
    color: var(--color-text);
    border-color: var(--color-text-muted);
}

/* ==================== */
/* EXTERNAL LINKS       */
/* ==================== */

.external-link::after {
    content: " \2197"; /* North-east arrow */
    font-size: 0.75em;
    opacity: 0.6;
}

/* ==================== */
/* ESSAY LAYOUT         */
/* ==================== */

.essay-content {
    margin-top: var(--space-lg);
}

.essay-footer {
    margin-top: var(--space-xl);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border-light);
}

/* ==================== */
/* CONTACT FORM         */
/* ==================== */

.contact-form {
    max-width: 500px;
    margin: var(--space-lg) 0;
}

.form-group {
    margin-bottom: var(--space-md);
}

.form-group label {
    display: block;
    margin-bottom: var(--space-xs);
    font-weight: 500;
    font-size: var(--font-size-small);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: var(--space-sm) var(--space-md);
    font-family: var(--font-serif);
    font-size: 1rem;
    border: 1px solid var(--color-border);
    border-radius: 4px;
    background: var(--color-bg);
    color: var(--color-text);
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-link);
    box-shadow: 0 0 0 3px rgba(43, 74, 111, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.submit-button {
    display: inline-block;
    padding: var(--space-sm) var(--space-lg);
    font-family: var(--font-sans);
    font-size: var(--font-size-small);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-bg);
    background: var(--color-text);
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.15s ease, transform 0.1s ease;
}

.submit-button:hover {
    background: var(--color-link);
}

.submit-button:active {
    transform: translateY(1px);
}

/* ==================== */
/* DETAILS/SUMMARY      */
/* ==================== */

details {
    margin: var(--space-sm) 0 var(--space-md) 0;
}

details summary {
    cursor: pointer;
    color: var(--color-text-muted);
    font-size: var(--font-size-small);
}

details summary:hover {
    color: var(--color-text);
}

details[open] summary {
    margin-bottom: var(--space-sm);
}

details > *:not(summary) {
    margin-left: var(--space-md);
}