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

[hidden] {
    display: none !important;
}

html {
    -webkit-text-size-adjust: 100%;
    text-size-adjust: 100%;
}

body {
    margin: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    font-family: var(--font);
    font-size: 1rem;
    line-height: 1.55;
    background: var(--bg);
    color: var(--text);
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3 {
    line-height: 1.2;
    letter-spacing: -0.01em;
    color: var(--text);
}

h1 {
    font-size: clamp(1.6rem, 4vw, 2.25rem);
    font-weight: 800;
    margin: 0 0 var(--space-2);
}

h2 {
    font-size: 1.2rem;
    font-weight: 700;
    margin: 0 0 var(--space-3);
}

h3 {
    font-size: 1rem;
    font-weight: 700;
}

p {
    margin: 0 0 var(--space-3);
}

a {
    color: var(--brand);
    text-decoration: none;
    text-underline-offset: 0.18em;
}

a:hover {
    color: var(--brand-hover);
    text-decoration: underline;
}

p a:not([class]) {
    text-decoration: underline;
    text-decoration-thickness: 1px;
}

:focus-visible {
    outline: 2px solid var(--brand);
    outline-offset: 2px;
}

button,
input,
select {
    font: inherit;
    color: inherit;
}

button {
    cursor: pointer;
}

img,
svg {
    display: block;
    max-width: 100%;
}

code,
kbd {
    font-family: var(--font-mono);
    font-size: 0.88em;
    padding: 0.1rem 0.35rem;
    border-radius: 4px;
    background: var(--surface-2);
    border: 1px solid var(--border);
}

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

.skip-link {
    position: absolute;
    left: var(--space-4);
    top: -100px;
    z-index: 200;
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-sm);
    background: var(--brand);
    color: var(--brand-contrast);
    font-weight: 700;
}

.skip-link:focus {
    top: var(--space-2);
}

.container {
    width: min(var(--container), 100% - 2rem);
    margin-inline: auto;
}

.muted {
    color: var(--muted);
}

/* --- Header --- */

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: color-mix(in srgb, var(--surface) 88%, transparent);
    backdrop-filter: saturate(1.4) blur(10px);
    -webkit-backdrop-filter: saturate(1.4) blur(10px);
    border-bottom: 1px solid var(--border);
    transition: transform 0.22s ease;
}

.site-header.is-hidden {
    transform: translateY(-100%);
}

.header-reveal {
    position: fixed;
    z-index: 60;
    top: 0;
    right: max(0.75rem, env(safe-area-inset-right));
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 3rem;
    height: calc(1.9rem + env(safe-area-inset-top));
    padding: env(safe-area-inset-top) 0 0;
    border: 0;
    border-radius: 0 0 0.75rem 0.75rem;
    background: var(--brand);
    color: var(--brand-contrast);
    box-shadow: 0 4px 12px -2px color-mix(in srgb, var(--brand) 45%, transparent);
    animation: header-reveal-in 0.2s ease-out;
}

.header-reveal:hover {
    filter: brightness(1.08);
}

.header-reveal:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring);
}

.header-reveal[hidden] {
    display: none;
}

.header-reveal svg {
    width: 1.2rem;
    height: 1.2rem;
    stroke-width: 2.6;
}

@keyframes header-reveal-in {
    from { transform: translateY(-100%); }
}

@media (prefers-reduced-motion: reduce) {
    .header-reveal { animation: none; }
}

@media (prefers-reduced-motion: reduce) {
    .site-header { transition: none; }
}

.header-inner {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    min-height: var(--header-h);
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 0.55rem;
    color: var(--text);
    text-decoration: none;
    flex-shrink: 0;
}

.logo:hover {
    text-decoration: none;
    color: var(--text);
}

.logo-mark {
    width: 2.25rem;
    height: 2.25rem;
    flex-shrink: 0;
    transition: transform 0.2s ease;
}

.logo:hover .logo-mark {
    transform: rotate(-6deg) scale(1.05);
}

.logo-mark-absent { fill: var(--tile-absent); }
.logo-mark-present { fill: var(--tile-present); }
.logo-mark-correct { fill: var(--tile-correct); }

.logo-mark-center {
    stroke: var(--surface);
    stroke-width: 2.5;
}

.logo-mark-text {
    fill: var(--tile-text);
    font-family: var(--font);
    font-weight: 800;
    text-anchor: middle;
}

.logo-word {
    font-size: 1.3rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    line-height: 1;
    color: var(--tile-correct);
}

.logo-word span {
    color: var(--text);
}

@media (prefers-reduced-motion: reduce) {
    .logo:hover .logo-mark { transform: none; }
}

.main-nav {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    margin-left: auto;
}

.main-nav a {
    display: inline-flex;
    align-items: center;
    min-height: 2.5rem;
    padding: 0 0.55rem;
    border-radius: var(--radius-sm);
    color: var(--text-2);
    font-weight: 600;
    font-size: 0.92rem;
    text-decoration: none;
    white-space: nowrap;
}

.main-nav a:hover {
    background: var(--surface-2);
    color: var(--text);
}

.main-nav a[aria-current="page"] {
    background: var(--brand-soft);
    color: var(--brand);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-1);
}

.icon-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    padding: 0;
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text-2);
}

.icon-btn:hover {
    background: var(--surface-2);
    color: var(--text);
}

.icon-btn svg {
    width: 1.25rem;
    height: 1.25rem;
}

.theme-toggle .icon-sun {
    display: none;
}

:root[data-theme="dark"] .theme-toggle .icon-sun {
    display: block;
}

:root[data-theme="dark"] .theme-toggle .icon-moon {
    display: none;
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) .theme-toggle .icon-sun {
        display: block;
    }

    :root:not([data-theme="light"]) .theme-toggle .icon-moon {
        display: none;
    }
}

.nav-toggle {
    display: none;
}

@media (max-width: 980px) {
    .nav-toggle {
        display: inline-flex;
    }

    .header-actions {
        margin-left: auto;
    }

    .main-nav {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        display: none;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        margin: 0;
        padding: var(--space-2) var(--space-4) var(--space-4);
        background: var(--surface);
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow-lg);
    }

    .main-nav.is-open {
        display: flex;
    }

    .main-nav a {
        min-height: 3rem;
        font-size: 1rem;
    }
}

/* --- Page layout --- */

.site-main {
    flex: 1;
    padding: var(--space-5) 0 var(--space-7);
}

.page-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-5);
}

@media (min-width: 1024px) {
    .page-grid--sidebar {
        grid-template-columns: minmax(0, 1fr) var(--sidebar);
        align-items: start;
    }
}

.page-content {
    min-width: 0;
}

.page-sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

@media (min-width: 1024px) {
    .page-sidebar {
        position: sticky;
        top: calc(var(--header-h) + var(--space-4));
    }
}

.page-head {
    margin-bottom: var(--space-5);
}

.lead {
    color: var(--muted);
    font-size: 1.05rem;
    margin: 0;
    max-width: 46rem;
}

.breadcrumbs {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
    margin: 0 0 var(--space-3);
    padding: 0;
    list-style: none;
    font-size: 0.88rem;
    color: var(--muted);
}

.breadcrumbs li + li::before {
    content: "/";
    margin-right: var(--space-2);
    color: var(--border-strong);
}

.breadcrumbs a {
    color: var(--muted);
}

/* --- Footer --- */

.site-footer {
    border-top: 1px solid var(--border);
    background: var(--surface);
    color: var(--muted);
    font-size: 0.9rem;
}

.footer-inner {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: var(--space-5);
    padding: var(--space-6) 0 var(--space-5);
}

.footer-title {
    margin: 0 0 var(--space-2);
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--text-2);
}

.footer-links {
    margin: 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: var(--space-1);
}

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

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

.footer-bottom {
    padding: var(--space-4) 0 var(--space-5);
    border-top: 1px solid var(--border);
    font-size: 0.85rem;
}

.footer-bottom p {
    margin: 0 0 var(--space-1);
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}