/* Structural layer, shared by every theme. Themes redefine the custom
   properties below and can override any class too. This file only handles
   layout, not final colors or fonts, so a theme stays a drop-in skin. */

:root {
    --bg: #f4f4f9;
    --surface: #ffffff;
    --surface-alt: #f0f0f5;
    --text: #1a1a1f;
    --text-muted: #6b6b76;
    --accent: #3b82f6;
    --accent-text: #ffffff;
    --border: #e2e2ea;
    --radius: 8px;
    --font-body: system-ui, -apple-system, "Segoe UI", sans-serif;
    --font-heading: var(--font-body);
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: var(--font-body);
    line-height: 1.5;
}

a {
    color: var(--accent);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

img {
    max-width: 100%;
}

.site-header {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 12px 24px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 16px;
    /* justify-content: space-between; */
}

.site-logo {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text);
}

.site-logo:hover {
    text-decoration: none;
}

.breadcrumb-bar {
    background: var(--surface-alt);
    border-bottom: 1px solid var(--border);
    padding: 10px 24px;
}

.breadcrumb {
    max-width: 960px;
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    align-items: center;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.breadcrumb a {
    color: var(--text-muted);
    font-weight: 600;
}

.breadcrumb a:hover {
    color: var(--accent);
    text-decoration: none;
}

.breadcrumb .crumb-current {
    color: var(--text);
    font-weight: 600;
}

.breadcrumb .crumb-sep {
    color: var(--text-muted);
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.control-form {
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.control-select {
    padding: 5px 10px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    font-family: inherit;
    font-size: 0.85rem;
}

.mode-toggle {
    font-size: 1rem;
    line-height: 1;
}

.user-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 3px 10px 3px 4px;
    border-radius: 999px;
    border: 1px solid var(--border);
    font-size: 0.85rem;
}

.user-chip .user-avatar {
    width: 22px;
    height: 22px;
    border-radius: 50%;
    object-fit: cover;
}

.user-chip a {
    color: var(--text-muted);
}

/* Visible to screen readers only. The <select> options already say what
   they are, but a label still ties them to something for assistive tech. */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.site-main {
    max-width: 960px;
    margin: 24px auto;
    padding: 0 16px 48px;
}

.site-footer {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.8rem;
    padding: 24px;
}

.page-title {
    font-family: var(--font-heading);
    margin: 0 0 16px;
}

.intro-text {
    color: var(--text-muted);
    max-width: 640px;
}

code {
    background: var(--surface-alt);
    border-radius: 4px;
    padding: 2px 6px;
    font-size: 0.9em;
}

.btn-invite {
    display: inline-block;
    background: var(--accent);
    color: var(--accent-text);
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius);
    font-family: inherit;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
}

.btn-invite:hover {
    text-decoration: none;
    filter: brightness(1.08);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 4px;
    max-width: 480px;
}

.contact-form label {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 8px;
}

.contact-form input,
.contact-form textarea {
    padding: 8px 12px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    font-family: inherit;
    font-size: 0.9rem;
    resize: vertical;
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: 2px solid var(--accent);
    outline-offset: -1px;
}

.contact-form button {
    margin-top: 16px;
    align-self: flex-start;
}

.contact-noscript {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.empty-state {
    background: var(--surface);
    border: 1px dashed var(--border);
    border-radius: var(--radius);
    padding: 32px;
    text-align: center;
    color: var(--text-muted);
}

.error-box {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px;
}

.error-box .status-code {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.list-controls {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    margin-bottom: 16px;
}

.filter-input {
    flex: 1 1 240px;
    padding: 7px 12px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    font-family: inherit;
    font-size: 0.9rem;
}

.filter-input:focus {
    outline: 2px solid var(--accent);
    outline-offset: -1px;
}

.sort-option {
    padding: 3px 10px;
    border-radius: 999px;
    border: 1px solid var(--border);
    color: var(--text);
    font-size: 0.85rem;
    white-space: nowrap;
}

.sort-option:hover {
    text-decoration: none;
    border-color: var(--accent);
}

/* Category list (home) */
.category-list {
    display: grid;
    gap: 16px;
}

.category-card {
    display: flex;
    gap: 16px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px;
    box-shadow: var(--shadow);
    align-items: center;
}

/* The `display: flex` above wins over the browser's default [hidden]
   rule (author styles beat the UA stylesheet), so without this the filter
   script's card.hidden = true wouldn't actually do anything. */
.category-card[hidden] {
    display: none;
}

.category-icon {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: var(--surface-alt);
    object-fit: cover;
    flex-shrink: 0;
}

.category-icon-fallback {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: var(--accent);
    color: var(--accent-text);
    display: flex;
    align-items: center;
    /* justify-content: center; */
    font-weight: 700;
    flex-shrink: 0;
}

.category-name {
    margin: 0 0 4px;
    font-size: 1.1rem;
}

.category-description {
    margin: 0 0 8px;
    color: var(--text-muted);
}

.category-meta {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.tag-list {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
}

.tag {
    background: var(--surface-alt);
    border-radius: 999px;
    padding: 2px 10px;
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Topic / thread rows (server page, forum page) */
.section-title {
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-muted);
    margin: 32px 0 8px;
}

.section-title:first-child {
    margin-top: 0;
}

.row-list {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
}

.row-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    border-bottom: 1px solid var(--border);
}

.row-item:last-child {
    border-bottom: none;
}

.row-main {
    flex: 1 1 auto;
    min-width: 0;
}

.row-title {
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 8px;
}

.row-title a {
    color: var(--text);
}

.row-sub {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 2px;
}

.row-stats {
    display: flex;
    gap: 16px;
    font-size: 0.8rem;
    color: var(--text-muted);
    text-align: right;
    flex-shrink: 0;
}

.row-stats .stat-value {
    display: block;
    color: var(--text);
    font-weight: 600;
}

.badge {
    background: var(--accent);
    color: var(--accent-text);
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.7rem;
}

.badge.locked {
    background: var(--text-muted);
}

/* Posts (topic page) */
.post-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.post {
    display: grid;
    grid-template-columns: 160px 1fr;
    gap: 16px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px;
}

.post-meta {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    text-align: center;
}

.post-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    object-fit: cover;
}

.post-author {
    font-weight: 600;
}

.post-date {
    color: var(--text-muted);
    font-size: 0.75rem;
}

.post-content {
    word-wrap: break-word;
}

.post-attachments {
    margin-top: 12px;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.post-attachments img {
    max-width: 240px;
    border-radius: 4px;
    display: block;
}

.post-attachments .attachment-link {
    display: inline-block;
    background: var(--surface-alt);
    border-radius: 4px;
    padding: 6px 10px;
    font-size: 0.85rem;
}

.reply-form {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-top: 16px;
}

.reply-form textarea {
    padding: 10px 12px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    font-family: inherit;
    font-size: 0.9rem;
    min-height: 96px;
    resize: vertical;
}

.reply-form textarea:focus {
    outline: 2px solid var(--accent);
    outline-offset: -1px;
}

.reply-form button {
    align-self: flex-start;
}

.error-banner {
    background: var(--surface);
    border: 1px solid var(--border);
    border-left: 3px solid var(--accent);
    border-radius: var(--radius);
    padding: 10px 14px;
    margin-top: 16px;
    font-size: 0.9rem;
}

@media (max-width: 600px) {
    .post {
        grid-template-columns: 1fr;
    }

    .row-item {
        flex-wrap: wrap;
    }

    .row-stats {
        text-align: left;
    }
}