/* ================================================================
   site-base.css — Global styles for chenhf.net
   All color values MUST be referenced via CSS variables from
   site-theme.css. No hardcoded hex/rgb color values allowed here.
   ================================================================ */


/* ----------------------------------------------------------------
   Reset & Box Model
   ---------------------------------------------------------------- */
*, *::before, *::after {
    box-sizing: border-box;
}

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
}

h1, h2, h3, h4, h5, h6, p {
    margin: 0;
    padding: 0;
    font: unset;
}

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


/* ----------------------------------------------------------------
   Base Typography
   ---------------------------------------------------------------- */
body {
    font-family: system-ui, "Segoe UI", Tahoma, sans-serif;
    font-size: 16px;
    line-height: 1.5;
    color: var(--text-primary);
    background-color: var(--body-bg);
    /* Smooth color transition for theme/brand switching */
    transition: background-color 0.2s ease, color 0.2s ease;
}

a:link,
a:visited,
a:active {
    color: var(--link-color);
    text-decoration: none;
}

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


/* ----------------------------------------------------------------
   Layout: Page Shell
   ---------------------------------------------------------------- */
.site-wrapper {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

main {
    flex: 1;
    padding: 1.25rem var(--content-padding-x);
}


/* ----------------------------------------------------------------
   Header
   ---------------------------------------------------------------- */
header {
    background-color: var(--header-bg);
    color: var(--header-text);
    padding: 0 var(--content-padding-x);
    transition: background-color 0.2s ease;
}

.site-header-inner {
    max-width: var(--content-max-width);
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.5rem 0;
    gap: 0.75rem;
}

.site-tagline {
    font-weight: bold;
    font-size: 16px;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.tagline-sep {
    opacity: 0.6;
}

.tagline-en {
    opacity: 0.9;
}


/* ----------------------------------------------------------------
   Site Controls (brand switcher + theme switcher)
   ---------------------------------------------------------------- */
.site-controls {
    display: flex;
    gap: 0.5rem;
    flex-shrink: 0;
    align-items: center;
}

.brand-switcher,
.theme-switcher {
    display: flex;
    gap: 0.25rem;
}

.brand-switcher button,
.theme-switcher button {
    background: transparent;
    border: 1px solid transparent;
    border-radius: 6px;
    color: var(--theme-btn-color);
    cursor: pointer;
    font-size: 16px;
    padding: 0.25rem 0.5rem;
    line-height: 1.5;
    transition: background-color 0.15s ease;
}

.brand-switcher button:hover,
.theme-switcher button:hover {
    background-color: var(--theme-btn-hover-bg);
}

.brand-switcher button.active,
.theme-switcher button.active {
    background-color: var(--theme-btn-active-bg);
    border-color: rgba(255, 255, 255, 0.4);
}


/* ----------------------------------------------------------------
   Navigation
   ---------------------------------------------------------------- */
nav {
    background-color: var(--nav-bg);
    border-bottom: 4px solid var(--nav-border);
    transition: background-color 0.2s ease, border-color 0.2s ease;
}

/* Desktop nav */
.nav-desktop {
    display: flex;
    max-width: var(--content-max-width);
    margin: 0 auto;
    padding: 0.25rem var(--content-padding-x);
    gap: 0.25rem;
}

.nav-desktop .nav-item {
    flex: 1;
    display: inline-block;
    border: 2px solid var(--nav-item-border);
    border-radius: 8px;
    color: var(--nav-item-color);
    font-size: 16px;
    font-weight: bold;
    line-height: 2;
    text-align: center;
    padding: 0 0.75rem;
    text-decoration: none;
    transition: background-color 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

.nav-desktop .nav-item:hover,
.nav-desktop .nav-item.active {
    background-color: var(--nav-item-hover-bg);
    color: var(--nav-item-hover-color);
    text-decoration: none;
}


/* ----------------------------------------------------------------
   Footer
   ---------------------------------------------------------------- */
footer {
    background-color: var(--footer-bg);
    color: var(--footer-text);
    text-align: center;
    padding: 0.75rem var(--content-padding-x);
    font-size: 16px;
    transition: background-color 0.2s ease;
}

.site-footer-inner {
    max-width: var(--content-max-width);
    margin: 0 auto;
}

footer a:link,
footer a:visited,
footer a:active {
    color: var(--footer-link);
    text-decoration: none;
}

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


/* ----------------------------------------------------------------
   Content Area: .page
   ---------------------------------------------------------------- */
.page {
    max-width: var(--content-max-width);
    margin: 0 auto;
    background-color: var(--content-bg);
    box-shadow: var(--content-shadow);
    padding: 0.25rem var(--content-padding-x) 1.5rem;
    transition: background-color 0.2s ease;
}


/* ----------------------------------------------------------------
   Page Headings (inside .page)
   ---------------------------------------------------------------- */
.page h1,
.page h2,
.page h3,
.page h4,
.page h5,
.page h6 {
    margin: 1rem 0 0.5rem;
    font-weight: bold;
    background-color: var(--heading-bg);
    transition: background-color 0.2s ease, border-color 0.2s ease;
}

.page h1 {
    font-size: 24px;
    text-align: center;
    line-height: 2;
    border: 4px dotted var(--h1-border-color);
    padding: 0.25rem 1rem;
}

.page h2 {
    font-size: 20px;
    line-height: 1.4;
    padding: 0.5rem 1rem;
    border-left: 8px solid var(--h2-border-color);
}

.page h3 {
    font-size: 16px;
    padding: 0.5rem 1rem;
    border-left: 8px solid var(--h3-border-color);
}

.page h4 {
    font-size: 16px;
    padding: 0.25rem 1rem;
    border-left: 8px dotted var(--h4-border-color);
}

.page h5 {
    font-size: 16px;
    padding: 0.25rem 1rem;
    border-left: 8px solid var(--h5-border-color);
}

.page h6 {
    font-size: 16px;
    padding: 0.25rem 1rem;
    border-left: 8px solid var(--h6-border-color);
}

/* "Go to top" button inside headings */
.gotop {
    float: right;
    font-size: 20px;
    font-weight: normal;
    line-height: 1.4;
    margin-left: 0.5rem;
    background: transparent;
    border: none;
    padding: 0;
    cursor: pointer;
    color: var(--link-color);
}

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


/* ----------------------------------------------------------------
   Page Body Elements
   ---------------------------------------------------------------- */
.page p {
    margin: 0.5rem 0;
    color: var(--text-primary);
}

.page > p {
    padding: 0 0.25rem;
}

.page ol,
.page ul {
    padding-left: 1.5rem;
    margin: 0.25rem 0;
}

.page li {
    margin: 0.25rem 0;
    color: var(--text-primary);
}

.page li > p {
    margin: 0.25rem 0;
}

.page blockquote {
    margin: 0.5rem 0;
    padding: 0.5rem 1rem;
    border: 1px solid var(--blockquote-border);
    border-left: 4px solid var(--blockquote-border);
    background-color: var(--blockquote-bg);
    color: var(--blockquote-text);
    border-radius: 0 4px 4px 0;
    transition: background-color 0.2s ease, border-color 0.2s ease;
}

.page blockquote p {
    color: var(--blockquote-text);
}

.page blockquote ul,
.page blockquote ol {
    padding-left: 1.25rem;
}

.page sup {
    font-size: 1em;
}

/* Horizontal rules */
.hr0 {
    margin: 0.75rem auto;
    height: 2px;
    background-color: var(--hr-light);
    border: none;
    max-width: 600px;
}

.home-banner {
    max-width: 600px;
    margin: 0.75rem auto 0;
}

.home-banner img {
    display: block;
    width: 100%;
    height: auto;
}

.hr1 {
    margin: 0.75rem 0;
    height: 2px;
    background-color: var(--hr-primary);
    border: none;
}


/* ----------------------------------------------------------------
   Table of Contents (.toc)
   ---------------------------------------------------------------- */
.toc {
    padding: 0.5rem 0.25rem;
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
    align-items: center;
}

.toc .toc-item {
    display: inline-block;
    border: 1px solid var(--toc-item-border);
    border-radius: 5px;
    padding: 0.25rem 0.75rem;
    font-size: 16px;
    color: var(--toc-item-color);
    text-decoration: none;
    transition: background-color 0.15s ease, color 0.15s ease;
    white-space: nowrap;
}

.toc .toc-item:hover {
    background-color: var(--toc-item-hover-bg);
    color: var(--toc-item-hover-color);
    text-decoration: none;
}

.toc .toc-item.empty {
    opacity: 0.4;
    cursor: default;
    pointer-events: none;
}


/* ----------------------------------------------------------------
   Homepage (.home)
   ---------------------------------------------------------------- */
.home {
    max-width: var(--content-max-width);
    margin: 0 auto;
    background-color: var(--content-bg);
    box-shadow: var(--content-shadow);
    text-align: center;
    padding: 2rem var(--content-padding-x) 1.75rem;
    transition: background-color 0.2s ease;
}

.home-avatar img {
    border-radius: 50%;
    width: 120px;
    height: 120px;
    object-fit: cover;
    margin: 0 auto 0.5rem;
    border: 4px solid var(--home-card-border);
    transition: border-color 0.2s ease;
}

.home-name h1 {
    font-size: 32px;
    font-weight: bold;
    line-height: 1.5;
    letter-spacing: 4px;
    color: var(--text-primary);
}

.home-name h2 {
    font-size: 20px;
    font-weight: bold;
    line-height: 1.4;
    letter-spacing: 2px;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

.home-position h3 {
    font-size: 16px;
    font-weight: bold;
    color: var(--text-primary);
    line-height: 1.75;
}

.home-contact {
    display: inline-block;
    text-align: left;
    margin: 0 auto;
}

.home-contact h3 {
    font-size: 16px;
    font-weight: normal;
    color: var(--text-primary);
    line-height: 2;
}

.home-contact .fa-solid,
.home-contact .fa-regular {
    color: var(--home-icon-color);
    width: 20px;
    text-align: center;
}

.home-nav {
    margin: 1.25rem auto 0.5rem;
    max-width: 600px;
    display: flex;
    gap: 0.5rem;
}

.home-nav a {
    flex: 1;
    border-radius: 10px;
    font-size: 20px;
    font-weight: bold;
    padding: 0.5rem 1rem;
    text-align: center;
    color: var(--link-color);
    text-decoration: none;
    line-height: 1.4;
    transition: background-color 0.15s ease, color 0.15s ease;
}

.home-nav a:hover {
    background-color: var(--home-card-hover-bg);
    color: var(--home-card-hover-color);
    text-decoration: none;
}

.home-nav .nav-label {
    display: block;
    font-size: 16px;
}

.home-nav .nav-code {
    display: block;
    font-size: 16px;
    font-family: monospace;
    opacity: 0.7;
}


/* ----------------------------------------------------------------
   Inline helpers
   ---------------------------------------------------------------- */
.hbox {
    display: inline-block;
}

.contact-row {
    display: flex;
    align-items: flex-start;
}

.contact-icon {
    flex-shrink: 0;
}

.contact-lines {
    display: block;
    flex: 1;
    min-width: 0;
}

.contact-lines span {
    display: block;
}

.text-muted {
    color: var(--text-muted);
    font-size: 16px;
}


/* ----------------------------------------------------------------
   Copy email button
   ---------------------------------------------------------------- */
.copy-email-btn {
    background: transparent;
    border: none;
    padding: 0 0 0 0.35rem;
    cursor: pointer;
    color: var(--home-icon-color);
    font-size: 14px;
    opacity: 0.55;
    line-height: 1;
    vertical-align: middle;
    transition: opacity 0.15s ease;
}

.copy-email-btn:hover {
    opacity: 1;
}


/* ----------------------------------------------------------------
   Dark mode: dim banner image slightly
   ---------------------------------------------------------------- */
[data-theme="dark"] .home-banner img {
    filter: brightness(0.85);
}


/* ----------------------------------------------------------------
   Print styles
   ---------------------------------------------------------------- */
@media print {
    nav,
    .theme-switcher,
    footer .fa-solar-panel {
        display: none !important;
    }

    .page,
    .home {
        box-shadow: none;
    }
}


/* ----------------------------------------------------------------
   Publication search box (.pub-search)
   ---------------------------------------------------------------- */
.pub-search {
    padding: 0.5rem 0.25rem 0.25rem;
}

.pub-search input[type="search"] {
    width: 100%;
    padding: 0.5rem 0.75rem;
    font-size: 16px;
    border: 2px solid var(--toc-item-border);
    border-radius: 6px;
    background-color: var(--content-bg);
    color: var(--text-primary);
    outline: none;
    transition: border-color 0.15s ease, background-color 0.2s ease;
}

.pub-search input[type="search"]:focus {
    border-color: var(--link-color);
}


/* ----------------------------------------------------------------
   404 page (.page-404)
   ---------------------------------------------------------------- */
.page-404 {
    max-width: var(--content-max-width);
    margin: 40px auto;
    background-color: var(--content-bg);
    box-shadow: var(--content-shadow);
    text-align: center;
    padding: 60px 24px;
    transition: background-color 0.2s ease;
}

.page-404 .code {
    font-size: 80px;
    font-weight: bold;
    color: var(--h1-border-color);
    line-height: 1.1;
}

.page-404 .msg-zh {
    font-size: 22px;
    font-weight: bold;
    color: var(--text-primary);
    margin: 16px 0 8px;
}

.page-404 .msg-en {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.page-404 .hint {
    font-size: 16px;
    color: var(--text-muted);
    margin-bottom: 20px;
}

.page-404 .home-link {
    display: inline-block;
    border: 2px solid var(--home-card-border);
    border-radius: 8px;
    padding: 8px 24px;
    font-size: 16px;
    font-weight: bold;
    color: var(--link-color);
    text-decoration: none;
    transition: background-color 0.15s ease, color 0.15s ease;
}

.page-404 .home-link:hover {
    background-color: var(--home-card-hover-bg);
    color: var(--home-card-hover-color);
    text-decoration: none;
}