/* === CSS Variables === */
:root {
  --color-primary: #1a365d;
  --color-primary-light: #2b6cb0;
  --color-text: #1a202c;
  --color-text-secondary: #4a5568;
  --color-border: #e2e8f0;
  --color-bg: #ffffff;
  --color-bg-secondary: #f7fafc;
  --color-accent: #c53030;
  --font-serif: "Times New Roman", "Georgia", "Noto Serif", serif;
  --font-sans: "Helvetica Neue", "Arial", "Noto Sans", sans-serif;
  --font-mono: "SFMono-Regular", "Consolas", "Liberation Mono", monospace;
  --max-width: 960px;
}

/* === Reset === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-text-size-adjust: 100%; }
body { font-family: var(--font-sans); color: var(--color-text); background: var(--color-bg); line-height: 1.6; }
a { color: var(--color-primary-light); text-decoration: underline; }
a:hover { color: var(--color-primary); }
img { max-width: 100%; height: auto; }
ul { list-style: none; }

/* === Layout === */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 1rem; }

/* === Header === */
.site-header { border-bottom: 1px solid var(--color-border); background: var(--color-bg); position: sticky; top: 0; z-index: 100; }
.header-inner { display: flex; align-items: center; justify-content: space-between; padding-top: 0.75rem; padding-bottom: 0.75rem; flex-wrap: wrap; }
.site-title { font-family: var(--font-serif); font-size: 1.25rem; font-weight: 700; color: var(--color-primary); text-decoration: none; }
.issn { font-size: 0.8rem; color: var(--color-text-secondary); margin-left: 0.5rem; }

/* === Navigation === */
.nav-toggle { display: none; }
.nav-hamburger { display: none; cursor: pointer; font-size: 1.5rem; color: var(--color-primary); }
.nav-links { display: flex; gap: 1.5rem; }
.nav-links a { font-size: 0.9rem; color: var(--color-text); text-decoration: none; font-weight: 500; }
.nav-links a:hover { color: var(--color-primary); text-decoration: underline; }

/* === Main === */
main { min-height: 60vh; padding: 2rem 0; }

/* === Footer === */
.site-footer { border-top: 1px solid var(--color-border); padding: 1.5rem 0; margin-top: 3rem; }
.site-footer p { font-size: 0.85rem; color: var(--color-text-secondary); }

/* === Typography === */
h1, h2, h3, h4 { font-family: var(--font-serif); color: var(--color-primary); line-height: 1.3; }
h1 { font-size: 1.75rem; margin-bottom: 1rem; }
h2 { font-size: 1.4rem; margin-bottom: 0.75rem; margin-top: 1.5rem; }
h3 { font-size: 1.15rem; margin-bottom: 0.5rem; }
p { margin-bottom: 1rem; }

/* === Article Card === */
.article-card { border-bottom: 1px solid var(--color-border); padding: 1.25rem 0; }
.article-card:last-child { border-bottom: none; }
.article-type { font-size: 0.8rem; color: var(--color-text-secondary); text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 0.25rem; }
.article-title { font-family: var(--font-serif); font-size: 1.15rem; font-weight: 600; margin-bottom: 0.35rem; }
.article-title a { color: var(--color-text); text-decoration: none; }
.article-title a:hover { color: var(--color-primary-light); text-decoration: underline; }
.article-authors { font-size: 0.9rem; color: var(--color-text-secondary); margin-bottom: 0.35rem; }
.article-meta { font-size: 0.8rem; color: var(--color-text-secondary); font-family: var(--font-mono); }
.article-abstract { font-size: 0.9rem; color: var(--color-text-secondary); margin-top: 0.5rem; line-height: 1.5; }
.article-links { margin-top: 0.5rem; }
.article-links a { font-size: 0.85rem; margin-right: 1rem; }

/* === Article Detail === */
.article-detail .breadcrumb { font-size: 0.85rem; color: var(--color-text-secondary); margin-bottom: 1.5rem; }
.article-detail .breadcrumb a { color: var(--color-text-secondary); }
.article-detail .detail-type { font-size: 0.85rem; color: var(--color-text-secondary); text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 0.5rem; }
.article-detail .detail-title { font-family: var(--font-serif); font-size: 1.5rem; font-weight: 700; line-height: 1.3; margin-bottom: 1rem; }
.article-detail .detail-authors { margin-bottom: 1.5rem; }
.article-detail .author-name { font-size: 1rem; }
.article-detail .author-affiliation { font-size: 0.85rem; color: var(--color-text-secondary); margin-left: 0.25rem; }
.article-detail .corresponding-mark { color: var(--color-accent); font-weight: bold; }
.article-detail .detail-abstract { background: var(--color-bg-secondary); padding: 1.25rem; margin-bottom: 1.5rem; border-left: 3px solid var(--color-primary); }
.article-detail .detail-abstract h2 { margin-top: 0; }
.article-detail .keywords { font-size: 0.9rem; margin-bottom: 1.5rem; }
.article-detail .keywords strong { color: var(--color-primary); }
.article-detail .detail-meta { font-size: 0.85rem; color: var(--color-text-secondary); margin-bottom: 1.5rem; line-height: 1.8; }
.article-detail .detail-body { line-height: 1.8; font-size: 1rem; }
.article-detail .detail-body h2 { font-size: 1.25rem; margin-top: 2rem; }
.article-detail .references { margin-top: 2rem; }
.article-detail .references ol { padding-left: 1.5rem; }
.article-detail .references li { font-size: 0.85rem; margin-bottom: 0.5rem; line-height: 1.5; color: var(--color-text-secondary); }

/* === PDF Button === */
.btn-pdf { display: inline-block; background: var(--color-accent); color: #fff; padding: 0.6rem 1.25rem; text-decoration: none; font-size: 0.9rem; font-weight: 600; border: none; cursor: pointer; }
.btn-pdf:hover { background: #9b2c2c; color: #fff; text-decoration: none; }

/* === DOI Link === */
.doi-link { font-family: var(--font-mono); font-size: 0.85rem; }

/* === Volume List === */
.volume-item { border-bottom: 1px solid var(--color-border); padding: 1rem 0; }
.volume-item:last-child { border-bottom: none; }
.volume-title { font-family: var(--font-serif); font-size: 1.1rem; font-weight: 600; }
.volume-meta { font-size: 0.85rem; color: var(--color-text-secondary); }

/* === Journal Info Pages === */
.info-content { line-height: 1.8; }
.info-content h2 { font-size: 1.25rem; margin-top: 1.5rem; }
.info-content p { margin-bottom: 1rem; }
.info-content ul, .info-content ol { padding-left: 1.5rem; margin-bottom: 1rem; }
.info-content li { margin-bottom: 0.5rem; }

/* === Editorial Board === */
.editor-group { margin-bottom: 2rem; }
.editor-group h2 { border-bottom: 1px solid var(--color-border); padding-bottom: 0.5rem; }
.editor-card { padding: 0.75rem 0; border-bottom: 1px solid var(--color-border); }
.editor-card:last-child { border-bottom: none; }
.editor-name { font-weight: 600; font-size: 1rem; }
.editor-info { font-size: 0.85rem; color: var(--color-text-secondary); }

/* === Pagination === */
.pagination { display: flex; align-items: center; justify-content: center; gap: 0.5rem; margin: 2rem 0; }
.pagination a, .pagination span { padding: 0.4rem 0.8rem; font-size: 0.85rem; text-decoration: none; border: 1px solid var(--color-border); }
.pagination a:hover { background: var(--color-bg-secondary); }
.pagination .current { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }

/* === Search === */
.search-form { margin-bottom: 2rem; }
.search-form input[type="text"] { padding: 0.5rem; font-size: 1rem; width: 100%; max-width: 400px; border: 1px solid var(--color-border); }
.search-form button { padding: 0.5rem 1rem; font-size: 1rem; background: var(--color-primary); color: #fff; border: none; cursor: pointer; }

/* === Breadcrumb === */
.breadcrumb { font-size: 0.85rem; color: var(--color-text-secondary); margin-bottom: 1.5rem; }
.breadcrumb a { color: var(--color-text-secondary); }
.breadcrumb .separator { margin: 0 0.35rem; }

/* === Error Page === */
.error-page { text-align: center; padding: 4rem 0; }
.error-page h1 { font-size: 4rem; color: var(--color-text-secondary); }
.error-page p { font-size: 1.1rem; color: var(--color-text-secondary); margin-bottom: 1.5rem; }

/* === Journal Home === */
.journal-home .section-title { border-bottom: 1px solid var(--color-border); padding-bottom: 0.5rem; margin-bottom: 1rem; margin-top: 2rem; }
.journal-home .quick-links { display: flex; gap: 1rem; flex-wrap: wrap; margin: 1.5rem 0; }
.journal-home .quick-links a { padding: 0.5rem 1rem; border: 1px solid var(--color-border); font-size: 0.9rem; text-decoration: none; color: var(--color-text); }
.journal-home .quick-links a:hover { background: var(--color-bg-secondary); border-color: var(--color-primary); color: var(--color-primary); }

/* === Publisher Home === */
.publisher-home .journal-list { margin-top: 2rem; }
.publisher-home .journal-item { border-bottom: 1px solid var(--color-border); padding: 1.25rem 0; }
.publisher-home .journal-item:last-child { border-bottom: none; }
.publisher-home .journal-item h2 { margin: 0 0 0.25rem; }
.publisher-home .journal-item h2 a { color: var(--color-primary); text-decoration: none; }
.publisher-home .journal-item h2 a:hover { text-decoration: underline; }
.publisher-home .journal-item .journal-desc { font-size: 0.9rem; color: var(--color-text-secondary); }
.publisher-home .journal-item .journal-issn { font-size: 0.8rem; color: var(--color-text-secondary); font-family: var(--font-mono); }

/* === Responsive === */
@media (max-width: 768px) {
  .header-inner { flex-wrap: wrap; }
  .nav-hamburger { display: block; }
  .nav-links { display: none; width: 100%; flex-direction: column; gap: 0; padding-top: 0.5rem; }
  .nav-toggle:checked + .nav-hamburger + .nav-links { display: flex; }
  .nav-links li { border-top: 1px solid var(--color-border); }
  .nav-links a { display: block; padding: 0.75rem 0; }
  .article-detail .detail-title { font-size: 1.25rem; }
  .search-form input[type="text"] { max-width: 100%; }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .container { max-width: 90%; }
}