@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Playfair+Display:wght@600;700&display=swap');

:root {
  --primary: #1a5276;
  --primary-dark: #0e3a56;
  --primary-light: #2980b9;
  --accent: #e74c3c;
  --accent-hover: #c0392b;
  --bg: #f8f9fa;
  --white: #ffffff;
  --text: #2c3e50;
  --text-light: #7f8c8d;
  --border: #dee2e6;
  --success: #27ae60;
  --warning: #f39c12;
  --info: #3498db;
  --dark: #1a1a2e;
  --sidebar-dark: #1e293b;
  --sidebar-hover: #334155;
  --gradient: linear-gradient(135deg, #1a5276 0%, #2980b9 100%);
  --shadow: 0 4px 24px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.12);
  --radius: 12px;
  --radius-sm: 8px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: 'Inter', sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { text-decoration: none; color: inherit; transition: var(--transition); }
img { max-width: 100%; height: auto; }
button { cursor: pointer; border: none; font-family: inherit; }
input, select, textarea { font-family: inherit; }

/* ===== NAVBAR ===== */
.navbar {
  background: var(--white);
  box-shadow: 0 2px 16px rgba(0,0,0,0.06);
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 3px solid var(--primary);
}

.navbar-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  height: 72px;
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: 14px;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--primary);
}

.navbar-brand img { height: 48px; }
.navbar-brand span { max-width: 280px; line-height: 1.3; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 6px;
  list-style: none;
}

.nav-links a {
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-weight: 500;
  font-size: 0.92rem;
  color: var(--text);
  transition: var(--transition);
}

.nav-links a:hover, .nav-links a.active {
  background: var(--primary);
  color: var(--white);
}

.nav-links .btn-login {
  background: var(--primary);
  color: var(--white);
  padding: 8px 20px;
  border-radius: 24px;
  font-weight: 600;
  margin-left: 8px;
}

.nav-links .btn-login:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  padding: 8px;
}

.hamburger span {
  width: 24px;
  height: 2.5px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--transition);
}

/* ===== HERO ===== */
.hero {
  background: var(--gradient);
  color: var(--white);
  padding: 80px 24px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-content {
  max-width: 900px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.hero h1 {
  font-family: 'Playfair Display', serif;
  font-size: 2.8rem;
  font-weight: 700;
  margin-bottom: 16px;
  line-height: 1.2;
}

.hero .subtitle {
  font-size: 1.15rem;
  opacity: 0.9;
  margin-bottom: 12px;
  font-weight: 300;
}

.hero .badges {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-top: 20px;
  flex-wrap: wrap;
}

.hero .badge {
  background: rgba(255,255,255,0.2);
  backdrop-filter: blur(10px);
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 500;
  border: 1px solid rgba(255,255,255,0.3);
}

.hero .btn-submit {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--accent);
  color: var(--white);
  padding: 14px 32px;
  border-radius: 30px;
  font-size: 1rem;
  font-weight: 600;
  margin-top: 28px;
  transition: var(--transition);
  box-shadow: 0 4px 20px rgba(231,76,60,0.4);
}

.hero .btn-submit:hover {
  background: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(231,76,60,0.5);
}

/* ===== STATS ===== */
.stats-bar {
  background: var(--white);
  padding: 32px 24px;
  box-shadow: var(--shadow);
}

.stats-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.stat-item {
  text-align: center;
  padding: 16px;
}

.stat-number {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-top: 6px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* ===== SECTION STYLES ===== */
.section {
  padding: 60px 24px;
  max-width: 1200px;
  margin: 0 auto;
}

.section-title {
  font-family: 'Playfair Display', serif;
  font-size: 1.8rem;
  color: var(--primary);
  margin-bottom: 32px;
  position: relative;
  padding-bottom: 12px;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
}

.section-title.center { text-align: center; }
.section-title.center::after { left: 50%; transform: translateX(-50%); }

/* ===== ARTICLE CARDS ===== */
.articles-grid {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.article-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  transition: var(--transition);
  border-left: 4px solid var(--primary);
}

.article-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.article-card .category-badge {
  display: inline-block;
  background: rgba(26,82,118,0.1);
  color: var(--primary);
  padding: 4px 12px;
  border-radius: 16px;
  font-size: 0.78rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.article-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 8px;
  line-height: 1.4;
}

.article-card h3 a:hover { color: var(--primary-light); }

.article-card .authors {
  color: var(--text-light);
  font-size: 0.88rem;
  margin-bottom: 12px;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 0.82rem;
  color: var(--text-light);
}

.article-meta span {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ===== ABOUT SECTION ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}

.about-text p { margin-bottom: 16px; line-height: 1.8; }

.info-cards {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.info-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  display: flex;
  align-items: center;
  gap: 16px;
}

.info-card .icon {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--gradient);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.info-card h4 { font-size: 0.92rem; font-weight: 600; }
.info-card p { font-size: 0.85rem; color: var(--text-light); }

/* ===== FOOTER ===== */
.footer {
  background: var(--dark);
  color: rgba(255,255,255,0.8);
  padding: 48px 24px 24px;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
}

.footer h4 {
  color: var(--white);
  font-size: 1rem;
  margin-bottom: 16px;
  font-weight: 600;
}

.footer p, .footer a { font-size: 0.88rem; line-height: 1.8; }
.footer a:hover { color: var(--primary-light); }
.footer ul { list-style: none; }
.footer ul li { margin-bottom: 6px; }

.footer-bottom {
  max-width: 1200px;
  margin: 32px auto 0;
  padding-top: 20px;
  border-top: 1px solid rgba(255,255,255,0.1);
  text-align: center;
  font-size: 0.82rem;
  color: rgba(255,255,255,0.5);
}

/* ===== PAGE HEADER ===== */
.page-header {
  background: var(--gradient);
  color: var(--white);
  padding: 48px 24px;
  text-align: center;
}

.page-header h1 {
  font-family: 'Playfair Display', serif;
  font-size: 2.2rem;
  margin-bottom: 8px;
}

.page-header p {
  opacity: 0.85;
  font-size: 1rem;
}

/* ===== CONTACT ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  margin-top: 32px;
}

.contact-form {
  background: var(--white);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-weight: 600;
  font-size: 0.88rem;
  margin-bottom: 6px;
  color: var(--text);
}

.form-group input, .form-group select, .form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  transition: var(--transition);
  background: var(--white);
}

.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
  border-color: var(--primary);
  outline: none;
  box-shadow: 0 0 0 4px rgba(26,82,118,0.1);
}

.form-group textarea { min-height: 120px; resize: vertical; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.92rem;
  transition: var(--transition);
  border: none;
}

.btn-primary {
  background: var(--primary);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
}

.btn-accent {
  background: var(--accent);
  color: var(--white);
}

.btn-accent:hover {
  background: var(--accent-hover);
}

.btn-success {
  background: var(--success);
  color: var(--white);
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
}

.btn-outline:hover {
  background: var(--primary);
  color: var(--white);
}

.btn-sm { padding: 8px 16px; font-size: 0.82rem; }
.btn-block { width: 100%; justify-content: center; }

.contact-info-side {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.contact-info-card {
  background: var(--white);
  padding: 24px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.contact-info-card .ci-icon {
  width: 44px;
  height: 44px;
  background: var(--gradient);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.contact-info-card h4 { font-size: 0.95rem; margin-bottom: 4px; }
.contact-info-card p { font-size: 0.88rem; color: var(--text-light); }

/* ===== ARTICLE PAGE ===== */
.article-page {
  max-width: 1200px;
  margin: 0 auto;
  padding: 32px 24px;
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 32px;
}

.article-main { min-width: 0; }

.article-main h1 {
  font-family: 'Playfair Display', serif;
  font-size: 1.8rem;
  line-height: 1.3;
  margin-bottom: 16px;
  color: var(--primary-dark);
}

.article-authors-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
}

.article-authors-list .author-chip {
  background: rgba(26,82,118,0.08);
  padding: 4px 12px;
  border-radius: 16px;
  font-size: 0.85rem;
  color: var(--primary);
  font-weight: 500;
}

.article-section {
  margin-bottom: 28px;
}

.article-section h2 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--border);
}

.article-section p { line-height: 1.8; }

.keywords-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.keywords-list span {
  background: var(--bg);
  padding: 4px 12px;
  border-radius: 16px;
  font-size: 0.82rem;
  border: 1px solid var(--border);
}

.article-sidebar .sidebar-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  margin-bottom: 20px;
}

.sidebar-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--primary);
}

.sidebar-card .detail-row {
  display: flex;
  justify-content: space-between;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.85rem;
}

.sidebar-card .detail-row:last-child { border-bottom: none; }
.sidebar-card .detail-row .label { color: var(--text-light); }
.sidebar-card .detail-row .value { font-weight: 600; }

.btn-download-pdf {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  padding: 14px;
  background: var(--accent);
  color: var(--white);
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 0.95rem;
  transition: var(--transition);
}

.btn-download-pdf:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
}

/* ===== VOLUME/ISSUE HEADER ===== */
.issue-header {
  background: var(--white);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  margin-bottom: 28px;
  display: flex;
  align-items: center;
  gap: 20px;
}

.issue-header .issue-cover {
  width: 80px;
  height: 100px;
  background: var(--gradient);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-weight: 700;
  font-size: 0.8rem;
  text-align: center;
  flex-shrink: 0;
}

.issue-header h2 { font-size: 1.3rem; font-weight: 700; }
.issue-header p { color: var(--text-light); font-size: 0.9rem; }

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .hamburger { display: flex; }
  
  .nav-links {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 16px;
    box-shadow: var(--shadow-lg);
    gap: 4px;
  }
  
  .nav-links.active { display: flex; }
  .nav-links a { width: 100%; padding: 12px 16px; }

  .hero h1 { font-size: 1.8rem; }
  .hero { padding: 48px 16px; }
  .stats-inner { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .stat-number { font-size: 1.6rem; }
  .about-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 24px; }
  .article-page { grid-template-columns: 1fr; }
  .navbar-brand span { display: none; }
}