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

:root {
  --blue-50: #E6F1FB; --blue-100: #B5D4F4; --blue-200: #85B7EB;
  --blue-400: #378ADD; --blue-600: #185FA5; --blue-800: #0C447C; --blue-900: #042C53;
  --teal-50: #E1F5EE; --teal-400: #1D9E75; --teal-600: #0F6E56; --teal-800: #085041;
  --gray-50: #F1EFE8; --gray-100: #D3D1C7; --gray-200: #B4B2A9;
  --gray-400: #888780; --gray-600: #5F5E5A; --gray-800: #444441;
  --amber-50: #FAEEDA; --amber-400: #BA7517; --amber-600: #854F0B; --amber-800: #633806;
  --coral-50: #FAECE7; --coral-400: #D85A30; --coral-600: #993C1D; --coral-800: #712B13;

  --bg: #f8f8f6;
  --surface: #ffffff;
  --surface2: #f1efe8;
  --border: rgba(0,0,0,0.08);
  --border-med: rgba(0,0,0,0.14);
  --text: #1a1a18;
  --text-2: #5f5e5a;
  --text-3: #888780;
  --accent: #185FA5;
  --accent-bg: #E6F1FB;
  --accent-text: #0C447C;
  --radius: 10px;
  --radius-lg: 14px;
}

body {
  font-family: 'Vazirmatn', sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; }

/* ── NAV ── */
nav {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
  position: sticky;
  top: 0;
  z-index: 100;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}
.nav-logo-mark {
  width: 34px; height: 34px;
  background: var(--blue-800);
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
}
.nav-logo-mark i { font-size: 18px; color: #fff; }
.nav-logo-name { font-size: 17px; font-weight: 700; color: var(--text); }
.nav-logo-name span { color: var(--accent); }
.nav-links { display: flex; gap: 4px; }
.nav-link {
  font-size: 13px; color: var(--text-2);
  text-decoration: none; padding: 6px 12px;
  border-radius: 8px; transition: all .15s;
  border: none; background: none; cursor: pointer;
  font-family: 'Vazirmatn', sans-serif;
}
.nav-link:hover { background: var(--surface2); color: var(--text); }
.nav-link.active { background: var(--accent-bg); color: var(--accent-text); font-weight: 500; }
.nav-cta {
  font-size: 13px; font-weight: 500;
  background: var(--blue-800); color: #fff;
  border: none; padding: 7px 16px;
  border-radius: 8px; cursor: pointer;
  font-family: 'Vazirmatn', sans-serif;
  transition: background .15s;
}
.nav-cta:hover { background: var(--blue-900); }

/* ── PAGES ── */
.page { display: none; }
.page.active { display: block; }

/* ══════════════════════════════
   PAGE 1 — KNOWLEDGE LIST
══════════════════════════════ */
.kn-hero {
  background: var(--blue-800);
  padding: 2.5rem 2rem 3.5rem;
  margin-top: 80px;
  position: relative;
  overflow: hidden;
}
.kn-hero::before {
  content: '';
  position: absolute; top: -40px; left: -40px;
  width: 280px; height: 280px;
  border: 60px solid rgba(255,255,255,0.05);
  border-radius: 50%;
}
.kn-hero::after {
  content: '';
  position: absolute; bottom: -60px; right: 10%;
  width: 200px; height: 200px;
  border: 40px solid rgba(255,255,255,0.04);
  border-radius: 50%;
}
.kn-hero-inner { max-width: 860px; margin: 0 auto; position: relative; }
.kn-hero-badge {
  display: inline-flex; align-items: center; gap: 5px;
  background: rgba(255,255,255,0.12);
  color: rgba(255,255,255,0.85);
  font-size: 12px; padding: 4px 12px;
  border-radius: 20px; margin-bottom: 1rem;
  border: 1px solid rgba(255,255,255,0.15);
}
.kn-hero h1 {
  font-size: 30px; font-weight: 700;
  color: #fff; margin-bottom: 10px; line-height: 1.4;
}
.kn-hero p {
  font-size: 15px; color: rgba(255,255,255,0.72);
  max-width: 540px; line-height: 1.8;
}
.kn-stats {
  display: flex; gap: 2rem; margin-top: 2rem;
}

.kn-stat-num { font-size: 22px; font-weight: 700; color: #fff; }
.kn-stat-label { font-size: 12px; color: rgba(255,255,255,0.6); }

.kn-body { max-width: 1050px; margin: 0 auto; padding: 2rem; }

/* filter bar */
.kn-filterbar {
  display: flex; gap: 10px; flex-wrap: wrap;
  align-items: center; margin-bottom: 1.5rem;
}
.kn-search {
  flex: 1; min-width: 200px;
  position: relative;
}
.kn-search i {
  position: absolute; right: 11px; top: 50%;
  transform: translateY(-50%);
  font-size: 16px; color: var(--text-3);
  pointer-events: none;
}
.kn-search input {
  width: 100%; padding: 9px 36px 9px 12px;
  border: 1px solid var(--border-med);
  border-radius: var(--radius);
  background: var(--surface);
  font-family: 'Vazirmatn', sans-serif;
  font-size: 13px; color: var(--text);
  outline: none; transition: border-color .15s;
}
.kn-search input:focus { border-color: var(--accent); }
.cat-pills { display: flex; gap: 6px; flex-wrap: wrap; }
.cat-pill {
  font-size: 12px; padding: 5px 13px;
  border-radius: 20px;
  border: 1px solid var(--border-med);
  background: var(--surface); color: var(--text-2);
  cursor: pointer; font-family: 'Vazirmatn', sans-serif;
  transition: all .15s;
}
.cat-pill:hover { border-color: var(--accent); color: var(--accent); }
.cat-pill.active {
  background: var(--accent-bg);
  border-color: var(--blue-200);
  color: var(--accent-text); font-weight: 500;
}

/* featured article */
.feat-label {
  font-size: 12px; color: var(--text-3);
  font-weight: 500; margin-bottom: 10px;
  display: flex; align-items: center; gap: 5px;
}
.feat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  display: grid; grid-template-columns: 1fr 280px;
  overflow: hidden; margin-bottom: 2rem;
  cursor: pointer; transition: border-color .15s;
}
.feat-card:hover { border-color: var(--border-med); }
.feat-card-body { padding: 1.75rem; }
.feat-cat-badge {
  display: inline-block;
  font-size: 11px; font-weight: 500;
  padding: 3px 10px; border-radius: 20px;
  margin-bottom: 12px;
}
.feat-card-body h2 {
  font-size: 20px; font-weight: 700;
  color: var(--text); margin-bottom: 10px; line-height: 1.5;
}
.feat-card-body p {
  font-size: 13px; color: var(--text-2);
  line-height: 1.8; margin-bottom: 16px;
}
.feat-meta {
  display: flex; align-items: center;
  gap: 14px; font-size: 12px; color: var(--text-3);
}
.feat-meta-item { display: flex; align-items: center; gap: 4px; }
.read-more {
  display: inline-flex; align-items: center; gap: 5px;
  font-size: 13px; color: var(--accent); font-weight: 500;
  background: none; border: none; cursor: pointer;
  font-family: 'Vazirmatn', sans-serif; padding: 0;
  margin-top: 14px;
}
.read-more:hover { text-decoration: underline; }
.feat-card-img {
  background: var(--blue-50);
  display: flex; align-items: center; justify-content: center;
  flex-direction: column; gap: 8px;
}
.feat-card-img i { font-size: 52px; color: var(--blue-400); }
.feat-card-img span { font-size: 12px; color: var(--blue-600); }

/* articles grid */
.articles-header {
  display: flex; align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
}
.articles-header h3 { font-size: 15px; font-weight: 500; color: var(--text); }
.articles-header span { font-size: 12px; color: var(--text-3); }
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 12px;
  margin-bottom: 2rem;
}
.art-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  cursor: pointer;
  transition: border-color .15s, transform .15s;
  display: flex; flex-direction: column;
}
.art-card:hover { border-color: var(--border-med); transform: translateY(-2px); }
.art-card-icon {
  width: 40px; height: 40px;
  border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 12px; flex-shrink: 0;
}
.art-card-icon i { font-size: 20px; }
.art-cat-pill {
  font-size: 11px; font-weight: 500;
  padding: 2px 9px; border-radius: 20px;
  display: inline-block; margin-bottom: 8px;
}
.art-card h4 {
  font-size: 14px; font-weight: 500;
  color: var(--text); line-height: 1.55;
  margin-bottom: 8px; flex: 1;
}
.art-card-footer {
  display: flex; align-items: center;
  justify-content: space-between;
  font-size: 11px; color: var(--text-3);
  margin-top: 10px; padding-top: 10px;
  border-top: 1px solid var(--border);
}
.art-card-footer-left { display: flex; align-items: center; gap: 8px; }

/* topics section */
.topics-section { margin-bottom: 2rem; }
.topics-section h3 { font-size: 15px; font-weight: 500; color: var(--text); margin-bottom: 12px; }
.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 8px;
}
.topic-tile {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  cursor: pointer;
  transition: all .15s;
  display: flex; flex-direction: column; gap: 6px;
}
.topic-tile:hover { border-color: var(--border-med); background: var(--surface2); }
.topic-tile i { font-size: 22px; }
.topic-tile-name { font-size: 13px; font-weight: 500; color: var(--text); }
.topic-tile-count { font-size: 11px; color: var(--text-3); }

/* pagination */
.pagination {
  display: flex; align-items: center;
  justify-content: center; gap: 6px;
  padding: 1rem 0;
}
.page-btn {
  width: 34px; height: 34px;
  border-radius: 8px;
  border: 1px solid var(--border-med);
  background: var(--surface);
  font-size: 13px; color: var(--text-2);
  cursor: pointer; display: flex;
  align-items: center; justify-content: center;
  font-family: 'Vazirmatn', sans-serif;
  transition: all .15s;
}
.page-btn:hover { border-color: var(--accent); color: var(--accent); }

/* ══════════════════════════════
   RESPONSIVE
══════════════════════════════ */
@media (max-width: 900px) {
  .feat-card {
    grid-template-columns: 1fr;
  }
  .feat-card-img {
    order: -1;
    min-height: 160px;
  }
}

@media (max-width: 768px) {
  nav {
    padding: 0 1rem;
    height: auto;
    min-height: 60px;
    flex-wrap: wrap;
    gap: 8px;
  }
  .nav-links {
    flex-wrap: wrap;
    gap: 2px;
  }

  .kn-hero {
    padding: 2rem 1.25rem 2.5rem;
    margin-top: 70px;
  }
  .kn-hero h1 { font-size: 22px; }
  .kn-hero p { font-size: 13.5px; }
  .kn-stats { gap: 1.25rem; margin-top: 1.5rem; flex-wrap: wrap; }

  .kn-body { padding: 1.25rem; }

  .kn-filterbar {
    flex-direction: column;
    align-items: stretch;
  }
  .kn-search { min-width: 0; }
  .cat-pills { width: 100%; }

  .feat-card-body { padding: 1.25rem; }
  .feat-card-body h2 { font-size: 17px; }

  .articles-grid {
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 10px;
  }

  .topics-grid {
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  }

  .articles-header {
    flex-wrap: wrap;
    gap: 6px;
  }

  .pagination {
    flex-wrap: wrap;
  }
}

@media (max-width: 480px) {
  .kn-hero h1 { font-size: 19px; }
  .kn-stat-num { font-size: 18px; }

  .articles-grid {
    grid-template-columns: 1fr 1fr;
  }
}