/* ==========================================
   EXAMSYLLABUS - GLOBAL VARIABLES & BASE
   ========================================== */
:root {
  --blue: #2563eb;
  --blue-dark: #1d4ed8;
  --navy: #0f172a;
  --navy-2: #111c33;
  --ink: #111827;
  --gray-600: #4b5563;
  --gray-500: #6b7280;
  --gray-400: #9ca3af;
  --border: #e5e7eb;
  --bg-soft: #f8fafc;
  --topbar: #0b1220;
  --radius: 12px;
  --gradient: linear-gradient(135deg, #2563eb 0%, #4f46e5 100%);
  --gold: #f59e0b;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: #eef1f6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; margin: 0; padding: 0; }
button { font-family: inherit; cursor: pointer; }
img { max-width: 100%; display: block; }
.icon { width: 1em; height: 1em; stroke-width: 2; flex-shrink: 0; }

.site-container {
  max-width: 1120px;
  margin: 0 auto;
  background: #ffffff;
  box-shadow: 0 0 50px rgba(15,23,42,.08);
  overflow: hidden;
}

.wrap {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ==========================================
   DESKTOP HEADER
   ========================================== */
header.site-header {
  position: sticky;
  top: 0;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  z-index: 50;
  box-shadow: 0 1px 0 rgba(15,23,42,.06), 0 8px 24px -12px rgba(15,23,42,.08);
}

header.site-header::after {
  content: "";
  display: block;
  height: 2px;
  background: var(--gradient);
  opacity: .9;
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 16px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 9px;
  font-size: 18px;
  font-weight: 800;
  color: var(--ink);
  letter-spacing: -.2px;
  flex-shrink: 0;
}

.logo-badge {
  width: 34px; height: 34px;
  border-radius: 9px;
  background: var(--gradient);
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 4px 10px -2px rgba(37,99,235,.45);
  flex-shrink: 0;
}

.logo-badge .icon { width: 18px; height: 18px; color: #fff; }
.logo span.accent { color: var(--blue); }

nav.main-nav {
  display: flex;
  align-items: center;
  gap: 22px;
  font-size: 14px;
  font-weight: 600;
  color: #374151;
}

nav.main-nav a {
  padding: 6px 1px;
  position: relative;
  transition: color .15s;
  white-space: nowrap;
}

nav.main-nav a::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -2px;
  height: 2px;
  border-radius: 2px;
  background: var(--gradient);
  transform: scaleX(0);
  transition: transform .2s ease;
}

nav.main-nav a:hover { color: var(--blue); }
nav.main-nav a:hover::after { transform: scaleX(1); }
nav.main-nav a.active { color: var(--blue); }
nav.main-nav a.active::after { transform: scaleX(1); }

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.icon-btn {
  width: 36px; height: 36px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: #fff;
  display: flex; align-items: center; justify-content: center;
  color: #374151;
  transition: background .15s, border-color .15s;
}

.icon-btn:hover { background: var(--bg-soft); border-color: #c7d2fe; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 18px;
  border-radius: 9px;
  font-size: 14px;
  font-weight: 700;
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient);
  color: #fff;
  box-shadow: 0 4px 12px -3px rgba(37,99,235,.5);
}

.btn-primary:hover { filter: brightness(1.06); }

/* ==========================================
   MOBILE HIDE LOGIC FOR HEADER
   ========================================== */
@media (max-width: 900px) {
  nav.main-nav { display: none; }
}

@media (max-width: 640px) {
  /* Mobile mein header poori tarah hide ho jayega */
  header.site-header {
    display: none !important;
  }
}