/*
 * POPULAR AI | Journal stylesheet
 * Target: Open Journal Systems 3.5, PKP Default Theme
 * Version: 1.0 (2026-10-15)
 *
 * Install through: Settings > Website > Appearance > Advanced > Journal Style Sheet
 * Scope: the journal's public theme. Does not modify OJS application files.
 * Design: editorial masthead, restrained mint accents, readable research typography.
 */

/* --------------------------------------------------------------------------
   01. Design tokens
   -------------------------------------------------------------------------- */
:root {
  --pai-mint: #34d1a6;
  --pai-forest: #238c6f;
  --pai-deep-mint: #175e4b;
  --pai-mist-mint: #d6f8ee;
  --pai-ink: #1f1d24;
  --pai-charcoal: #35333b;
  --pai-slate: #6d6974;
  --pai-mist: #f9faf9;
  --pai-callout: #eaebea;
  --pai-line: #dfe5e2;
  --pai-white: #ffffff;
  --pai-font-ui: "Segoe UI", Inter, -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  --pai-font-editorial: Georgia, "Times New Roman", serif;
}

/* --------------------------------------------------------------------------
   02. Baseline: clean, quiet, readable
   -------------------------------------------------------------------------- */
html,
body {
  background: var(--pai-white);
  color: var(--pai-charcoal);
  font-family: var(--pai-font-ui);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body { font-size: 16px; }

/* Brand mint is too light for ordinary text on white. Use deep mint for links. */
a,
.pkp_structure_main a {
  color: var(--pai-deep-mint);
  text-underline-offset: 0.15em;
  text-decoration-thickness: 1px;
}

a:hover,
.pkp_structure_main a:hover {
  color: #104a39;
}

/* Respect keyboard navigation. Do not remove the OJS focus indication. */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid var(--pai-forest);
  outline-offset: 3px;
}

::selection {
  color: var(--pai-ink);
  background: var(--pai-mist-mint);
}

/* --------------------------------------------------------------------------
   03. Journal masthead
   -------------------------------------------------------------------------- */
.pkp_structure_head {
  background: var(--pai-white);
  border-top: 5px solid var(--pai-mint);
  border-bottom: 1px solid var(--pai-line);
  box-shadow: none;
}

.pkp_head_wrapper,
.pkp_site_name_wrapper,
.pkp_site_name {
  background: var(--pai-white);
}

.pkp_site_name .is_text {
  color: var(--pai-ink);
  font-family: var(--pai-font-ui);
  font-weight: 800;
  letter-spacing: -0.035em;
}

/* Logo: keep the existing Popular AI icon, wordmark, ™, and journal tagline. */
.pkp_site_name .is_img img {
  display: block;
  width: auto;
  height: auto;
  max-width: 100%;
}

/* --------------------------------------------------------------------------
   04. Navigation: compact editorial hierarchy
   -------------------------------------------------------------------------- */
.pkp_site_nav_menu {
  background: var(--pai-white);
}

.pkp_site_nav_menu a,
.pkp_navigation_primary > li > a,
.pkp_navigation_user > li > a,
.pkp_navigation_search_wrapper a {
  color: var(--pai-charcoal);
}

.pkp_navigation_primary > li > a {
  font-family: var(--pai-font-ui);
  font-size: 0.79rem;
  font-weight: 750;
  letter-spacing: 0.065em;
  text-transform: uppercase;
  border-bottom: 3px solid transparent;
}

.pkp_navigation_primary > li > a:hover,
.pkp_navigation_primary > li > a:focus,
.pkp_navigation_primary > li > a[aria-current="page"] {
  color: var(--pai-deep-mint);
  border-bottom-color: var(--pai-mint);
  background: transparent;
}

/* Desktop drop-downs retain OJS positioning and keyboard behavior. */
.pkp_navigation_primary ul {
  background: var(--pai-white);
  border: 1px solid var(--pai-line);
  border-radius: 2px;
  box-shadow: 0 10px 26px rgba(31, 29, 36, 0.09);
}

.pkp_navigation_primary ul a {
  color: var(--pai-charcoal);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: normal;
  text-transform: none;
}

.pkp_navigation_primary ul a:hover,
.pkp_navigation_primary ul a:focus {
  background: var(--pai-mist);
  color: var(--pai-deep-mint);
  border-left-color: var(--pai-mint);
}

.pkp_navigation_user > li > a:hover,
.pkp_navigation_search_wrapper a:hover {
  color: var(--pai-deep-mint);
}

/* --------------------------------------------------------------------------
   05. Reading area and page typography
   -------------------------------------------------------------------------- */
.pkp_structure_content {
  background: var(--pai-white);
}

.pkp_structure_main {
  color: var(--pai-charcoal);
}

/* The Default Theme draws full-height rules around the article column. */
.pkp_structure_main::before,
.pkp_structure_main::after {
  background-color: transparent;
}

.pkp_structure_main h1,
.pkp_structure_main h2,
.pkp_structure_main h3 {
  color: var(--pai-ink);
  letter-spacing: -0.025em;
}

.pkp_structure_main h1,
.pkp_structure_main .page > h1 {
  font-family: var(--pai-font-editorial);
  font-size: clamp(2rem, 3vw, 2.75rem);
  font-weight: 700;
  line-height: 1.16;
}

.pkp_structure_main h2 {
  font-family: var(--pai-font-editorial);
  font-weight: 700;
  line-height: 1.25;
}

.pkp_structure_main h3 {
  font-family: var(--pai-font-ui);
  font-weight: 700;
  line-height: 1.35;
}

.pkp_structure_main p,
.pkp_structure_main li {
  line-height: 1.75;
}

.pkp_structure_main p {
  max-width: 76ch;
}

.pkp_structure_main hr {
  border: 0;
  border-top: 1px solid var(--pai-line);
}

/* --------------------------------------------------------------------------
   06. Homepage: journal identity, sections and announcements
   -------------------------------------------------------------------------- */
.pkp_page_index .homepage_about {
  padding-top: 2.25rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid var(--pai-line);
}

.pkp_page_index .homepage_about h2 {
  font-family: var(--pai-font-editorial);
  font-size: clamp(1.6rem, 2.5vw, 2rem);
  line-height: 1.22;
}

.pkp_page_index .homepage_about p {
  color: var(--pai-charcoal);
  font-size: 1.05rem;
  line-height: 1.8;
}

.pkp_page_index .additional_content {
  border-top: 1px solid var(--pai-line);
  padding-top: 2rem;
  padding-bottom: 1.5rem;
}

.pkp_page_index .cmp_announcements {
  border-color: var(--pai-line);
}

.pkp_page_index .cmp_announcements .obj_announcement_summary {
  background: var(--pai-white);
}

/* Issue and section headings read as editorial departments. */
.pkp_page_index .current_issue > h2,
.pkp_page_index .current_issue .current_issue_title,
.pkp_page_index .section > h2 {
  color: var(--pai-ink);
  font-family: var(--pai-font-editorial);
  font-weight: 700;
}

/* --------------------------------------------------------------------------
   07. Article lists: stronger hierarchy, less visual clutter
   -------------------------------------------------------------------------- */
.obj_article_summary {
  padding-top: 1.15rem;
  padding-bottom: 1.4rem;
  border-bottom: 1px solid var(--pai-line);
}

.obj_article_summary > .title {
  margin-bottom: 0.4rem;
  font-family: var(--pai-font-editorial);
  font-size: clamp(1.2rem, 1.6vw, 1.5rem);
  font-weight: 700;
  line-height: 1.34;
  letter-spacing: -0.015em;
}

.obj_article_summary > .title a {
  color: var(--pai-ink);
  text-decoration: none;
}

.obj_article_summary > .title a:hover,
.obj_article_summary > .title a:focus-visible {
  color: var(--pai-deep-mint);
  text-decoration: underline;
}

.obj_article_summary .subtitle {
  color: var(--pai-slate);
  font-size: 0.97rem;
}

.obj_article_summary .meta,
.obj_article_summary .authors,
.obj_article_summary .pages,
.obj_article_summary .published {
  color: var(--pai-slate);
  font-size: 0.89rem;
  line-height: 1.6;
}

.obj_article_summary .cover img {
  border: 1px solid var(--pai-line);
  box-shadow: none;
}

/* --------------------------------------------------------------------------
   08. Article landing pages: publication-grade reading experience
   -------------------------------------------------------------------------- */
.obj_article_details > .page_title {
  max-width: 26ch;
  margin-bottom: 1rem;
  color: var(--pai-ink);
  font-family: var(--pai-font-editorial);
  font-size: clamp(2rem, 3.1vw, 2.8rem);
  font-weight: 700;
  line-height: 1.18;
  letter-spacing: -0.03em;
}

.obj_article_details > .subtitle {
  color: var(--pai-slate);
  line-height: 1.5;
}

.obj_article_details .authors {
  color: var(--pai-charcoal);
  font-size: 0.96rem;
  line-height: 1.7;
}

.obj_article_details .item > .label,
.obj_article_details .item .label,
.obj_article_details .sub_item .label {
  color: var(--pai-ink);
  font-family: var(--pai-font-ui);
  font-weight: 750;
}

.obj_article_details .item.doi,
.obj_article_details .item.keywords {
  overflow-wrap: anywhere;
}

.obj_article_details .abstract,
.obj_article_details .item.abstract {
  line-height: 1.8;
}

.obj_article_details .abstract p {
  line-height: 1.8;
}

.obj_article_details .references {
  font-size: 0.94rem;
  line-height: 1.75;
  overflow-wrap: anywhere;
}

/* --------------------------------------------------------------------------
   09. PDF/HTML download links and primary actions
   -------------------------------------------------------------------------- */
.obj_galley_link,
.obj_article_details .obj_galley_link {
  display: inline-block;
  background: var(--pai-deep-mint);
  border: 1px solid var(--pai-deep-mint);
  border-radius: 3px;
  color: var(--pai-white);
  font-family: var(--pai-font-ui);
  font-size: 0.84rem;
  font-weight: 700;
  letter-spacing: 0.025em;
  text-decoration: none;
  transition: background-color 150ms ease, border-color 150ms ease;
}

.obj_galley_link:hover,
.obj_galley_link:focus,
.obj_article_details .obj_galley_link:hover,
.obj_article_details .obj_galley_link:focus {
  background: #104a39;
  border-color: #104a39;
  color: var(--pai-white);
  text-decoration: none;
}

.pkp_structure_main .cmp_button,
.pkp_structure_main a.cmp_button {
  border-color: var(--pai-deep-mint);
  color: var(--pai-deep-mint);
  border-radius: 3px;
  font-weight: 700;
}

.pkp_structure_main .cmp_button:hover,
.pkp_structure_main a.cmp_button:hover {
  background: var(--pai-mist-mint);
  border-color: var(--pai-deep-mint);
  color: var(--pai-deep-mint);
}

/* --------------------------------------------------------------------------
   10. Sidebars, breadcrumbs, metadata and auxiliary panels
   -------------------------------------------------------------------------- */
.pkp_structure_sidebar {
  color: var(--pai-charcoal);
  font-size: 0.93rem;
}

.pkp_structure_sidebar .block_custom,
.pkp_structure_sidebar .block_information,
.pkp_structure_sidebar .block_make_submission {
  border-top: 2px solid var(--pai-line);
  padding-top: 1rem;
}

.pkp_structure_sidebar h2,
.pkp_structure_sidebar h3 {
  color: var(--pai-ink);
  font-family: var(--pai-font-ui);
  font-weight: 750;
}

.pkp_structure_sidebar a {
  color: var(--pai-deep-mint);
}

.pkp_page_index .additional_content,
.pkp_structure_main blockquote {
  color: var(--pai-charcoal);
}

.pkp_structure_main blockquote {
  margin: 1.5rem 0;
  padding: 0.75rem 1.3rem;
  background: var(--pai-mist);
  border-left: 3px solid var(--pai-mint);
  font-style: normal;
}

.pkp_structure_main table {
  border-collapse: collapse;
}

.pkp_structure_main th,
.pkp_structure_main td {
  border-bottom: 1px solid var(--pai-line);
  padding: 0.65rem 0.8rem;
}

.pkp_structure_main th {
  background: var(--pai-mist);
  color: var(--pai-ink);
  text-align: left;
}

/* --------------------------------------------------------------------------
   11. Footer: understated publisher identity
   -------------------------------------------------------------------------- */
.pkp_structure_footer_wrapper {
  background: var(--pai-mist);
  border-top: 3px solid var(--pai-charcoal);
  color: var(--pai-charcoal);
}

.pkp_structure_footer,
.pkp_footer_content {
  color: var(--pai-charcoal);
}

.pkp_footer_content {
  padding-top: 2.1rem;
  padding-bottom: 2.1rem;
  font-size: 0.9rem;
  line-height: 1.75;
}

.pkp_structure_footer a {
  color: var(--pai-deep-mint);
}

.pkp_brand_footer {
  border-top: 1px solid var(--pai-line);
}

/* --------------------------------------------------------------------------
   12. Responsive safeguards: OJS controls retain their original behavior
   -------------------------------------------------------------------------- */
@media (min-width: 992px) {
  .has_site_logo .pkp_head_wrapper {
    padding-top: 2rem;
  }

  .pkp_site_name .is_img img {
    max-height: 38px;
    max-width: min(100%, 650px);
  }

  .pkp_navigation_primary_wrapper {
    border-top: 1px solid var(--pai-line);
    margin-top: 0.75rem;
  }

  .pkp_navigation_primary {
    text-align: left;
  }
}

@media (max-width: 991px) {
  .pkp_structure_head {
    border-top-width: 4px;
  }

  .pkp_site_name .is_img img {
    max-height: 38px;
    max-width: calc(100vw - 105px);
  }

  .pkp_site_nav_menu {
    border-bottom: 1px solid var(--pai-line);
    box-shadow: 0 12px 20px rgba(31, 29, 36, 0.06);
  }

  .pkp_site_nav_menu a {
    color: var(--pai-charcoal);
  }

  .pkp_navigation_primary > li > a {
    text-transform: none;
    font-size: 0.95rem;
    letter-spacing: 0;
    font-weight: 650;
  }
}

@media (max-width: 600px) {
  .pkp_structure_main h1,
  .obj_article_details > .page_title {
    font-size: 1.9rem;
    line-height: 1.2;
  }

  .obj_article_summary > .title {
    font-size: 1.2rem;
  }

  .pkp_page_index .homepage_about {
    padding-top: 1.2rem;
    padding-bottom: 1.6rem;
  }

  .pkp_structure_main p,
  .pkp_structure_main li {
    line-height: 1.65;
  }
}

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

@media print {
  .pkp_structure_head,
  .pkp_structure_footer_wrapper,
  .pkp_structure_sidebar {
    box-shadow: none;
  }

  .pkp_structure_main a {
    color: var(--pai-ink);
  }
}