:root{
  --primary:#0b1f3a;
  --primary-2:#123d70;
  --accent:#c8922b;
  --accent-soft:#fff7e6;
  --blue:#0b65b9;
  --green:#168a4a;
  --bg:#f5f7fb;
  --surface:#ffffff;
  --text:#1f2937;
  --muted:#667085;
  --border:#e3e8ef;
  --shadow:0 8px 24px rgba(15,23,42,.07);
  --radius:14px;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:Arial, Helvetica, sans-serif;
  font-size:15px;
  line-height:1.65;
  color:var(--text);
  background:var(--bg);
}
img{max-width:100%;height:auto}
a{color:var(--blue);text-decoration:none}
a:hover{text-decoration:underline}
.container{width:min(1160px,94%);margin:0 auto}

/* Header */
.site-header{background:var(--primary);position:sticky;top:0;z-index:50;box-shadow:0 4px 16px rgba(0,0,0,.12)}
.nav-wrap{display:flex;align-items:center;justify-content:space-between;gap:18px;min-height:68px}
.brand{display:flex;align-items:center;gap:10px;color:#fff;text-decoration:none;font-size:22px;font-weight:700;letter-spacing:.2px}
.brand:hover{text-decoration:none;color:#fff}
.book-icon{display:inline-flex;align-items:center;justify-content:center;width:36px;height:36px;border-radius:10px;background:var(--accent);color:var(--primary);font-size:19px}
.top-nav{display:flex;align-items:center;gap:4px;flex-wrap:wrap;justify-content:flex-end}
.top-nav a{color:#eef4fb;text-decoration:none;font-size:14px;font-weight:600;padding:10px 11px;border-radius:8px;line-height:1.2}
.top-nav a:hover{background:rgba(255,255,255,.12);text-decoration:none}
.menu-toggle{display:none;background:var(--accent);color:var(--primary);border:0;border-radius:8px;font-weight:700;padding:8px 12px;cursor:pointer}

/* Hero */
.hero.modern-hero{background:linear-gradient(135deg,var(--primary),var(--primary-2));color:#fff;padding:42px 0 46px}
.hero-grid{display:grid;grid-template-columns:300px minmax(0,1fr);gap:34px;align-items:center}
.cover-wrap{text-align:center}
.cover-wrap img{width:100%;max-width:300px;border-radius:16px;box-shadow:0 18px 40px rgba(0,0,0,.28);border:1px solid rgba(255,255,255,.18)}
.eyebrow,.section-kicker{display:inline-block;font-size:12px;font-weight:700;letter-spacing:.8px;text-transform:uppercase;color:var(--accent);margin-bottom:8px}
.section-kicker.light{color:#ffda86}
.hero h1{font-size:36px;line-height:1.18;margin:8px 0 12px;color:#fff;font-weight:700}
.hero-text{font-size:17px;line-height:1.7;color:#e3edf9;margin:0 0 16px;max-width:760px}
.badges{display:flex;flex-wrap:wrap;gap:8px;margin:15px 0 20px}
.badges span,.badge{display:inline-flex;align-items:center;background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.18);color:#fff;border-radius:999px;padding:7px 11px;font-size:12px;font-weight:600}
.hero-actions,.article-actions,.big-actions{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin-top:14px}

/* Buttons */
.btn-primary,.btn-small,.btn-light,.btn-outline,.btn-secondary,.btn-view,.btn-download,.btn-copy{
  display:inline-flex;align-items:center;justify-content:center;gap:6px;
  border-radius:9px;padding:10px 15px;font-size:14px;font-weight:700;text-decoration:none;border:1px solid transparent;cursor:pointer;line-height:1.25;
}
.btn-primary,.btn-small{background:var(--accent);color:var(--primary)!important;border-color:var(--accent)}
.btn-primary:hover,.btn-small:hover{background:#b9821f;text-decoration:none}
.btn-light,.btn-secondary{background:#fff;color:var(--primary)!important;border-color:#d9e0ea}
.btn-light:hover,.btn-secondary:hover{background:#f3f6fb;text-decoration:none}
.btn-outline{background:transparent;color:#fff!important;border-color:rgba(255,255,255,.7)}
.btn-view{background:var(--blue)!important;color:#fff!important;border-color:var(--blue)!important}
.btn-download{background:var(--green)!important;color:#fff!important;border-color:var(--green)!important}
.btn-copy{background:var(--accent)!important;color:var(--primary)!important;border-color:var(--accent)!important}

/* Layout */
.main{padding:34px 0 44px}
.grid{display:grid;grid-template-columns:minmax(0,2.1fr) minmax(280px,.9fr);gap:24px;align-items:start}
.card,.side-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow)}
.card{padding:24px;margin-bottom:22px}
.card h2{font-size:24px;line-height:1.25;color:var(--primary);margin:0 0 14px;padding-bottom:10px;border-bottom:2px solid var(--accent)}
.card h3{color:var(--primary)}
.math-content{overflow-x:auto;line-height:1.75}

/* Search panel */
.research-search-card{margin-bottom:22px;background:linear-gradient(135deg,var(--primary),var(--primary-2));color:#fff;border-radius:18px;padding:24px;box-shadow:var(--shadow);overflow:hidden;position:relative}
.research-search-card:after{content:"";position:absolute;right:-70px;top:-70px;width:180px;height:180px;border-radius:50%;background:rgba(200,146,43,.18)}
.search-panel{display:grid;grid-template-columns:64px minmax(0,1fr);gap:16px;align-items:center;position:relative;z-index:1}
.search-icon-large{width:64px;height:64px;border-radius:16px;background:rgba(255,255,255,.12);display:flex;align-items:center;justify-content:center;font-size:30px;border:1px solid rgba(255,255,255,.2)}
.search-copy h2{margin:0 0 5px;color:#fff;font-size:26px;line-height:1.2}
.search-copy p{margin:0;color:#e2ecf8;font-size:15px}
.research-search-form{grid-column:1/-1;display:flex;gap:10px;margin-top:8px}
.research-search-form input{flex:1;border:0;border-radius:10px;padding:14px 15px;font-size:15px;outline:none;min-width:0}
.research-search-form button{border:0;border-radius:10px;background:var(--accent);color:var(--primary);font-size:15px;font-weight:800;padding:0 24px;cursor:pointer}
.research-search-form button:hover{background:#b9821f}

/* Articles */
.article{background:#fff;border:1px solid var(--border);border-radius:13px;padding:18px;margin-bottom:15px;box-shadow:0 3px 12px rgba(15,23,42,.04)}
.article h3{margin:6px 0 8px;font-size:20px;line-height:1.35;color:var(--primary)}
.article h3 a{color:var(--primary);text-decoration:none}
.article h3 a:hover{text-decoration:underline}
.article-meta{color:var(--muted);font-size:12px;font-weight:700;text-transform:uppercase;letter-spacing:.35px}
.article-line{display:flex;gap:7px;flex-wrap:wrap;align-items:center;margin:9px 0;color:#344054}
.dotsep{color:#98a2b3}
.abstract-box{border-left:4px solid var(--accent);background:#fbfcff;padding:16px;border-radius:10px}
.reference-box{background:#f8fafc;border:1px solid var(--border);padding:14px;border-radius:10px;margin-bottom:10px;white-space:pre-wrap}

/* Sidebar */
.sidebar-widgets{min-width:0}
.side-card{padding:18px;margin-bottom:20px}
.side-card-head{display:flex;align-items:center;gap:10px;border-bottom:1px solid var(--border);padding-bottom:12px;margin-bottom:14px}
.side-head-icon{width:38px;height:38px;border-radius:11px;background:var(--primary);color:#fff;display:flex;align-items:center;justify-content:center;font-size:18px;flex:0 0 38px}
.side-card h2{font-size:20px;color:var(--primary);margin:0;font-weight:700}
.indexing-list{display:grid!important;grid-template-columns:1fr!important;gap:10px!important;width:100%}
.indexing-btn{width:100%;display:flex;align-items:center;gap:12px;background:#fff;border:1px solid #dbe6f2;border-left:4px solid var(--blue);border-radius:11px;padding:11px 13px;min-height:50px;color:var(--primary);box-shadow:0 3px 10px rgba(15,23,42,.04);transition:.18s ease}
.indexing-btn span{font-size:21px;width:28px;text-align:center;line-height:1;flex:0 0 28px}
.indexing-btn strong{font-size:14px;font-weight:700;line-height:1.2}
.indexing-btn:hover{background:#f3f8ff;transform:translateX(2px);border-left-color:var(--accent)}
.side-link-list{list-style:none;margin:0;padding:0}
.side-link-list li{margin-bottom:8px}
.side-link-list a{display:block;background:#f8fafc;border:1px solid var(--border);color:var(--primary);border-radius:10px;padding:11px 12px;font-weight:700;text-decoration:none}
.side-link-list a:hover{background:#edf5ff;border-color:#cfe0f3;text-decoration:none}
.info-table,.modern-info-table{width:100%;border-collapse:collapse}
.info-table td,.modern-info-table td{border-bottom:1px solid var(--border);padding:10px 3px;font-size:14px}
.modern-info-table td:last-child{text-align:right;color:var(--primary-2);font-weight:700}

/* Forms and tables */
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.field{margin-bottom:14px}
.field label{display:block;margin-bottom:6px;font-weight:700;color:var(--primary)}
.field input,.field textarea,.field select{width:100%;padding:12px;border:1px solid #cfd8e3;border-radius:10px;font-size:15px;background:#fff}
.field textarea{min-height:140px}
.field small{display:block;margin-top:6px;color:var(--muted)}
.notice{background:var(--accent-soft);border-left:4px solid var(--accent);padding:14px;border-radius:10px}
.success{background:#ebf8f0;border-left:4px solid var(--green);padding:14px;border-radius:10px}
.table{width:100%;border-collapse:collapse;background:#fff;border-radius:12px;overflow:hidden}
.table th,.table td{border:1px solid var(--border);padding:10px;text-align:left}
.table th{background:#f8fafc;color:var(--primary)}

/* Editorial board */
.editorial-page{padding:0;background:transparent;border:0;box-shadow:none}
.editorial-hero-card{background:linear-gradient(135deg,var(--primary),var(--primary-2));color:#fff;border-radius:18px;padding:26px;margin-bottom:22px;box-shadow:var(--shadow)}
.editorial-hero-card h2{color:#fff;margin:0 0 8px;font-size:28px}
.editorial-hero-card p{margin:0;color:#e5eefb}
.editorial-section{margin-top:24px;background:#fff;border:1px solid var(--border);border-radius:16px;padding:22px;box-shadow:var(--shadow)}
.editorial-section-title{display:flex;align-items:center;gap:12px;margin-bottom:16px}
.editorial-section-title span{width:42px;height:42px;border-radius:12px;background:#eef6ff;display:flex;align-items:center;justify-content:center;font-size:22px;flex:0 0 42px}
.editorial-section-title h3{margin:0;color:var(--primary);font-size:23px}
.editorial-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
.editor-profile-card{background:#fff;border:1px solid var(--border);border-radius:16px;padding:20px;box-shadow:0 6px 18px rgba(15,23,42,.06);position:relative;overflow:hidden}
.editor-profile-card:before{content:"";position:absolute;left:0;top:0;bottom:0;width:5px;background:var(--blue)}
.editor-profile-card.lead-card:before{background:var(--accent)}
.editor-avatar{width:72px;height:72px;border-radius:20px;background:var(--primary);display:flex;align-items:center;justify-content:center;color:#fff;font-size:36px;margin-bottom:13px}
.editor-profile-card h4{font-size:20px;color:var(--primary);margin:0 0 7px;line-height:1.3}
.editor-role{display:inline-block;background:#edf5ff;color:var(--primary-2);border-radius:999px;padding:5px 11px;font-weight:700;font-size:13px;margin-bottom:10px}
.editor-affiliation{font-size:14.5px;color:#344054;margin:0 0 12px;line-height:1.6}
.editor-links{display:flex;gap:8px;flex-wrap:wrap;margin-top:10px}
.editor-links a,.editor-links span{display:inline-flex;align-items:center;justify-content:center;min-width:40px;height:36px;border-radius:9px;background:#f8fafc;border:1px solid var(--border);color:var(--primary);font-weight:700;text-decoration:none}
.editor-links a:hover{background:#edf5ff;text-decoration:none}
.editor-interests{font-size:13px;color:var(--muted);margin-top:12px;border-top:1px solid var(--border);padding-top:10px}
.join-box,.editorial-final{background:#fff;border:1px solid var(--border);border-radius:16px;padding:22px;margin-top:22px;box-shadow:var(--shadow)}
.join-box{background:#fffaf0;border-color:#f2d49a}
.editorial-final{background:#f8fafc}

/* Footer */
.site-footer{background:var(--primary);color:#d8e6f7;padding:38px 0 0;margin-top:36px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1.2fr;gap:28px}
.site-footer h2,.site-footer h3{color:#fff;margin-top:0}
.site-footer p{color:#d8e6f7}
.site-footer ul{list-style:none;padding:0;margin:0}
.site-footer li{margin-bottom:8px}
.site-footer a{color:#fff;text-decoration:none}
.site-footer a:hover{text-decoration:underline}
.whatsapp{display:inline-block;background:#16a34a;color:#fff!important;padding:9px 12px;border-radius:8px;font-weight:700;text-decoration:none}
.footer-bottom{text-align:center;border-top:1px solid rgba(255,255,255,.15);margin-top:24px;padding:15px;color:#bcd0e7;font-size:14px}

/* Admin safety */
.admin-body{background:#eef2f7}.admin-wrap{display:grid;grid-template-columns:230px 1fr;min-height:100vh}.admin-side{background:var(--primary);color:white;padding:22px}.admin-side a{display:block;color:#dbeafe;text-decoration:none;padding:9px 0}.admin-main{padding:25px}.btn-tiny{display:inline-block;padding:5px 9px;border-radius:6px;background:var(--blue);color:#fff!important;text-decoration:none;font-size:12px;font-weight:700}.btn-tiny.danger{background:#dc3545}

/* Responsive */
@media(max-width:1020px){
  .grid{grid-template-columns:1fr}
  .sidebar-widgets{display:block}
  .hero-grid{grid-template-columns:260px minmax(0,1fr);gap:24px}
  .hero h1{font-size:32px}
}
@media(max-width:820px){
  .nav-wrap{min-height:64px;flex-wrap:wrap;position:relative}
  .menu-toggle{display:inline-block}
  .top-nav{display:none;position:absolute;top:62px;left:0;right:0;background:var(--primary);border-radius:0 0 12px 12px;padding:10px;box-shadow:0 12px 26px rgba(0,0,0,.18)}
  .top-nav.show{display:grid;grid-template-columns:1fr;gap:2px}
  .top-nav a{padding:12px}
  .hero.modern-hero{padding:28px 0 34px}
  .hero-grid{grid-template-columns:1fr;text-align:center}
  .cover-wrap img{max-width:220px}
  .hero h1{font-size:28px}
  .hero-text{font-size:15.5px}
  .badges,.hero-actions{justify-content:center}
  .search-panel{grid-template-columns:1fr;text-align:center}
  .search-icon-large{margin:0 auto}
  .research-search-form{flex-direction:column}
  .research-search-form button{padding:13px}
  .footer-grid{grid-template-columns:1fr}
  .form-row{grid-template-columns:1fr}
  .editorial-grid{grid-template-columns:1fr}
}
@media(max-width:520px){
  body{font-size:14.5px}
  .container{width:min(100% - 24px,1160px)}
  .brand{font-size:19px}
  .book-icon{width:32px;height:32px}
  .card,.side-card,.editorial-section{padding:17px;border-radius:13px}
  .card h2{font-size:21px}
  .search-copy h2{font-size:22px}
  .article h3{font-size:18px}
  .btn-primary,.btn-small,.btn-light{width:100%}
  .article-actions a{width:100%}
  .editor-avatar{width:64px;height:64px;font-size:31px}
  .editorial-hero-card{padding:20px}
}

.breadcrumbs{font-size:.92rem;margin-bottom:18px;color:#64748b;line-height:1.5}.breadcrumbs a{color:#2563eb;text-decoration:none}.breadcrumbs span{margin:0 4px}.breadcrumbs a:hover{text-decoration:underline}