@import url('https://fonts.googleapis.com/css2?family=EB+Garamond:wght@400;800&family=Sofia+Sans:wght@300;900&display=swap');

:root {
    --sidebar-width: 120px;
    --content-left: 0px;
    --radius-lg: 16px;
    --radius-md: 10px;
    --accent: #0066cc;
    --text: #555;
    --text-dark: #aaa;
    --nav-hover-light: rgba(0, 0, 0, 0.05);
    --nav-hover-dark: rgba(255, 255, 255, 0.05);
    --transition-link: color 0.2s, background 0.2s;

    --dark-bg: #1a1a1a;
    --dark-surface: #242424;
    --dark-surface-raised: #2a2a2a;
    --dark-border: #383838;
    --dark-accent: #4d9fff;
    --dark-text-strong: #e0e0e0;

    --bg: #fff;
    --border: #ddd;
    --surface: #f9f9f9;
    --active-bg: #f0f0f0;
    --control-bg: #e0e0e0;
    --text-strong: #333;
}

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

#progressBar {
    position: fixed;
    top: 0;
    left: 0;
    width: 0%;
    height: 3px;
    background: var(--accent);
    z-index: 2000;
    transition: width 0.1s linear;
    pointer-events: none;
}

html {
    overflow: hidden;
}

body {
    font-family: 'Sofia Sans', sans-serif;
    font-optical-sizing: auto;
    font-weight: 300;
    line-height: 1.6;
    color: var(--text-strong);
    background: var(--bg);
    position: fixed;
    top: 0;
    left: var(--content-left);
    right: 0;
    bottom: 0;
    overflow-y: auto;
    overflow-x: hidden;
    overflow-anchor: none;
}

/* Header & Navigation — desktop sidebar */
header {
    position: fixed;
    top: 60px;
    left: max(12px, calc((100vw + var(--content-left) - 800px) / 2 - 200px - var(--sidebar-width)));
    width: var(--sidebar-width);
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    padding: 12px 10px;
}

nav {
    display: flex;
    flex-direction: column;
    gap: 2px;
    width: 100%;
}

nav a {
    text-decoration: none;
    color: var(--text);
    font-size: 17px;
    padding: 8px 14px;
    text-align: center;
    border-radius: var(--radius-md);
    transition: var(--transition-link);
}

nav a:hover {
    color: var(--text-strong);
    background: var(--nav-hover-light);
}

nav a.active {
    background: var(--active-bg);
    color: var(--accent);
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 6px;
    position: fixed;
    top: 26px;
    right: 26px;
    z-index: 1002;
    transition: opacity 0.3s;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text-strong);
    transition: 0.3s;
}

.hamburger.active span:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
}


/* Main Content */
main {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 20px;
}

h1, h2, h3, nav a {
    font-family: 'Sofia Sans', sans-serif;
    font-weight: 900;
}

h1 {
    font-size: 37px;
    margin-bottom: 20px;
    color: var(--accent);
}

h2 {
    font-size: 28px;
    margin-top: 40px;
    margin-bottom: 15px;
    color: var(--text-strong);
}

p {
    margin-bottom: 15px;
    line-height: 1.8;
    color: var(--text);
}

section {
    margin-bottom: 50px;
}

main a {
    color: var(--accent);
}

html.dark main a {
    color: var(--dark-accent);
}

/* Post list on index page */
.post-list {
    list-style: none;
    margin-top: 30px;
}

.post-list li {
    margin-bottom: 24px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--border);
}

.post-list li:last-child {
    border-bottom: none;
}

.post-list a {
    font-size: 24px;
    font-weight: 900;
    color: var(--text-strong);
    text-decoration: none;
    transition: color 0.2s;
}

.post-list a:hover {
    color: var(--accent);
}

html.dark .post-list a {
    color: var(--dark-text-strong);
}

html.dark .post-list a:hover {
    color: var(--dark-accent);
}

html.dark .post-list li {
    border-bottom-color: var(--dark-border);
}

.post-list time {
    display: block;
    margin-top: 4px;
    font-size: 15px;
    color: var(--text);
}

html.dark .post-list time {
    color: var(--text-dark);
}

html.garamond .post-list a {
    font-family: 'EB Garamond', serif;
    font-weight: 800;
}

@media (max-width: 768px) {
    .post-list a {
        font-size: 20px;
    }
}

.content-block {
    background: var(--surface);
    padding: 30px;
    border-radius: 8px;
    margin: 20px 0;
}

/* Shared base for icon toggle buttons */
.theme-btn,
.font-btn,
.lang-btn {
    appearance: none;
    border: none;
    border-radius: 50%;
    width: 48px;
    height: 48px;
    cursor: pointer;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
}

/* Theme toggle */
.theme-btn {
    background: var(--control-bg);
    font-size: 22px;
    transition: background 0.3s;
}

.theme-btn::after {
    content: '🌙';
}

/* Dark theme */
html.dark body {
    color: var(--dark-text-strong);
    background: var(--dark-bg);
}

html.dark header {
    background: var(--dark-surface);
    border-color: var(--dark-border);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

html.dark nav a {
    color: var(--text-dark);
}

html.dark nav a.active {
    background: var(--dark-border);
    color: var(--dark-accent);
}

html.dark nav a:hover {
    color: var(--dark-text-strong);
    background: var(--nav-hover-dark);
}

html.dark .hamburger span {
    background: var(--dark-text-strong);
}

html.dark .content-block {
    background: var(--dark-surface);
}

html.dark h2 {
    color: var(--dark-text-strong);
}

html.dark p {
    color: var(--text-dark);
}

html.dark .theme-btn,
html.dark .font-btn,
html.dark .lang-btn {
    background: var(--dark-surface-raised);
}

html.dark .theme-btn::after {
    content: '☀️';
}

/* Garamond font variant */
html.garamond body {
    font-family: 'EB Garamond', serif;
    font-weight: 400;
    font-size: 20px;
    line-height: 1.3;
}

html.garamond h1, html.garamond h2, html.garamond h3,
html.garamond nav a {
    font-family: 'EB Garamond', serif;
    font-weight: 800;
}

html.garamond nav a {
    font-size: 21px;
}

/* Font toggle */
.font-btn {
    background: var(--control-bg);
    font-size: 24px;
    font-weight: 900;
    font-family: 'EB Garamond', serif;
    color: var(--text);
    transition: background 0.3s, color 0.3s;
}

html.garamond .font-btn {
    font-family: 'Sofia Sans', sans-serif;
    font-weight: 300;
}

.font-btn::after {
    content: 'A';
}

html.dark .font-btn {
    color: var(--text-dark);
}

/* Desktop sidebar button styles */
@media (min-width: 769px) {
    header .font-btn,
    header .theme-btn,
    header .lang-btn {
        align-self: center;
        margin-top: 8px;
        background: transparent;
        position: relative;
    }

    header .font-btn:hover,
    header .theme-btn:hover,
    header .lang-btn:hover {
        background: var(--nav-hover-light);
    }

    html.dark header .font-btn,
    html.dark header .theme-btn,
    html.dark header .lang-btn {
        background: transparent;
    }

    html.dark header .font-btn:hover,
    html.dark header .theme-btn:hover,
    html.dark header .lang-btn:hover {
        background: rgba(255, 255, 255, 0.08);
    }

    header .font-btn::before,
    header .theme-btn::before {
        content: attr(aria-label);
        position: absolute;
        top: calc(100% + 8px);
        left: 50%;
        transform: translateX(-50%);
        white-space: nowrap;
        background: var(--text);
        color: var(--bg);
        font-size: 14px;
        font-family: 'Sofia Sans', sans-serif;
        font-weight: 400;
        padding: 4px 8px;
        border-radius: 4px;
        pointer-events: none;
        opacity: 0;
        transition: opacity 0.15s;
        z-index: 100;
    }

    header .font-btn:hover::before,
    header .theme-btn:hover::before {
        opacity: 1;
    }

    html.dark header .font-btn::before,
    html.dark header .theme-btn::before {
        background: var(--dark-text-strong);
        color: var(--dark-bg);
    }
}

/* Language switcher */
.lang-btn {
    background: var(--control-bg);
    overflow: hidden;
    transition: background 0.3s;
}

.lang-btn img {
    width: 28px;
    height: 19px;
    border-radius: 3px;
    object-fit: cover;
    display: block;
}


/* Responsive */
@media (max-width: 768px) {
    body {
        left: 0;
        top: 0;
    }

    header {
        height: 0;
        padding: 0;
        background: none;
        border: none;
        box-shadow: none;
        overflow: visible;
        pointer-events: none;
    }

    nav {
        display: flex;
        flex-direction: row;
        flex-wrap: wrap;
        gap: 6px;
        position: fixed;
        top: 15px;
        left: 15px;
        right: 15px;
        width: auto;
        background: color-mix(in srgb, var(--bg) 5%, transparent);
        backdrop-filter: blur(10px);
        -webkit-backdrop-filter: blur(16px);
        border: 1px solid var(--border);
        border-radius: var(--radius-lg);
        padding: 16px 20px;
        z-index: 1001;
        box-shadow: 0 4px 24px rgba(0, 0, 0, 0.12);
        opacity: 0;
        pointer-events: none;
        transition: opacity 0.2s ease;
    }

    nav a {
        padding: 7px 12px;
        text-align: left;
    }

    nav.active {
        opacity: 1;
        pointer-events: auto;
    }

    html.dark nav {
        background: color-mix(in srgb, var(--dark-surface-raised) 5%, transparent);
        border-color: var(--dark-border);
        box-shadow: 0 4px 24px rgba(0, 0, 0, 0.5);
    }

    main {
        padding: 20px;
    }

    h1 {
        font-size: 28px;
    }

    h2 {
        font-size: 24px;
    }

    .hamburger {
        display: flex;
    }

    body.scrolling .hamburger {
        opacity: 0.3;
    }

    .lang-btn,
    .font-btn,
    .theme-btn {
        position: fixed;
        right: 20px;
        pointer-events: auto;
        display: flex;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.25);
    }

    .theme-btn { bottom: 24px; }
    .font-btn  { bottom: calc(24px + 48px + 10px); }
    .lang-btn  { bottom: calc(24px + 48px + 10px + 48px + 10px); }

    body.scrolling .lang-btn,
    body.scrolling .font-btn,
    body.scrolling .theme-btn {
        opacity: 0.3;
    }
}

/* Footnotes */
.footnote-ref {
    font-size: 0.72em;
    vertical-align: super;
    line-height: 0;
}

.footnote-ref a {
    color: var(--accent);
    text-decoration: none;
    padding: 0 1px;
    transition: color 0.2s;
}

.footnote-ref a:hover {
    text-decoration: underline;
}

section.footnotes {
    margin-top: 40px;
    padding-top: 20px;
    border-top: 1px solid var(--border);
    font-size: 0.88em;
    color: var(--text);
}

section.footnotes ol {
    padding-left: 1.4em;
}

section.footnotes li {
    margin-bottom: 6px;
    line-height: 1.6;
}

section.footnotes p {
    margin-bottom: 0;
    color: inherit;
    font-size: inherit;
    line-height: inherit;
}

.footnote-backref {
    color: var(--accent);
    text-decoration: none;
    margin-left: 4px;
    transition: color 0.2s;
}

.footnote-backref:hover {
    text-decoration: underline;
}

html.dark .footnote-ref a,
html.dark .footnote-backref {
    color: var(--dark-accent);
}

html.dark section.footnotes {
    border-top-color: var(--dark-border);
    color: var(--text-dark);
}

html.garamond section.footnotes {
    font-size: 0.82em;
}