@import url('https://fonts.googleapis.com/css2?family=Hind+Siliguri:wght@400;500;600;700&display=swap');

:root {
  --primary: #0f4c81;
  --primary-dark: #0a3558;
  --accent: #f59e0b;
  --green: #16a34a;
  --red: #dc2626;
  --bg: #f4f8fb;
  --text: #1f2937;
  --muted: #6b7280;
  --card: #ffffff;
  --border: #e2e8f0;
  --radius: 14px;
  --shadow: 0 4px 14px rgba(15, 76, 129, 0.10);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

body {
  margin: 0;
  font-family: 'Hind Siliguri', 'Noto Sans Bengali', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 17px;
}

img { max-width: 100%; display: block; }
a { color: var(--primary); }
h1, h2, h3 { line-height: 1.35; margin: 0 0 10px; color: var(--primary-dark); }

.container { width: 100%; max-width: 1100px; margin: 0 auto; padding: 0 16px; }

/* হেডার */
.site-header {
  background: var(--primary-dark);
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}
.nav { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 10px 16px; flex-wrap: wrap; }
.brand { color: #fff; font-weight: 700; font-size: 20px; text-decoration: none; }
.nav-links { display: flex; gap: 6px; overflow-x: auto; }
.nav-links a { color: #dbeafe; text-decoration: none; padding: 6px 12px; border-radius: 999px; white-space: nowrap; font-size: 16px; }
.nav-links a:hover, .nav-links a.active { background: rgba(255, 255, 255, 0.15); color: #fff; }

/* হিরো */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: #fff;
  padding: 44px 0 52px;
  text-align: center;
}
.hero h1 { color: #fff; font-size: 30px; }
.hero p { max-width: 640px; margin: 0 auto 20px; color: #dbeafe; }
.hero .btn-row { justify-content: center; }

/* সেকশন */
.section { padding: 36px 0; }
.section-title { font-size: 26px; text-align: center; margin-bottom: 4px; }
.section-sub { text-align: center; color: var(--muted); margin: 0 0 22px; }
.page-title { font-size: 26px; margin: 24px 0 14px; }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); gap: 18px; }

/* কার্ড */
.card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }
.card-pad { padding: 18px; }
.course-card { display: flex; flex-direction: column; }
.course-img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; background: #dbeafe; }
.course-body { padding: 16px; display: flex; flex-direction: column; gap: 6px; flex: 1; }
.course-body h3 { font-size: 20px; margin: 0; }
.course-body p { margin: 0; color: var(--muted); font-size: 16px; }
.badge { display: inline-block; background: #e0f2fe; color: var(--primary); padding: 2px 12px; border-radius: 999px; font-size: 14px; font-weight: 600; align-self: flex-start; }
.fee { font-size: 20px; font-weight: 700; color: var(--green); margin-top: 4px; }
.btn-row { display: flex; gap: 10px; flex-wrap: wrap; margin-top: auto; padding-top: 10px; }

/* বাটন */
.btn {
  display: inline-block;
  border: 0;
  cursor: pointer;
  font-family: inherit;
  font-size: 16px;
  font-weight: 600;
  padding: 10px 18px;
  border-radius: 10px;
  text-decoration: none;
  text-align: center;
  background: var(--primary);
  color: #fff;
}
.btn:hover { opacity: 0.92; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-outline { background: #fff; color: var(--primary); border: 2px solid var(--primary); padding: 8px 16px; }
.btn-accent { background: var(--accent); color: #1f2937; }
.btn-green { background: var(--green); }
.btn-danger { background: var(--red); }
.btn-small { padding: 6px 12px; font-size: 14px; }
.btn-block { display: block; width: 100%; }
.course-body .btn { flex: 1; min-width: 120px; }

/* ফর্ম */
.field { margin-bottom: 14px; }
.field label { display: block; font-weight: 600; margin-bottom: 4px; }
input, select, textarea {
  width: 100%;
  font-family: inherit;
  font-size: 16px;
  padding: 10px 12px;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  background: #fff;
  color: var(--text);
}
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--primary); }
textarea { min-height: 90px; resize: vertical; }
.hint { font-size: 14px; color: var(--muted); margin-top: 2px; }

.alert { padding: 12px 14px; border-radius: 10px; margin: 12px 0; font-weight: 500; }
.alert-success { background: #dcfce7; color: #166534; }
.alert-error { background: #fee2e2; color: #991b1b; }
.alert-info { background: #e0f2fe; color: #075985; }

.loading, .empty { text-align: center; color: var(--muted); padding: 30px 10px; }
.page-content { white-space: pre-wrap; word-wrap: break-word; }
.detail-img { width: 100%; max-height: 360px; object-fit: cover; border-radius: var(--radius); margin-bottom: 16px; }
.meta { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 12px; }

/* ফুটার */
.footer { background: var(--primary-dark); color: #bfdbfe; text-align: center; padding: 20px 16px; margin-top: 30px; font-size: 15px; }

/* পরীক্ষা */
.exam-bar {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--primary-dark);
  color: #fff;
  padding: 10px 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
}
.timer { font-size: 22px; font-weight: 700; color: #fde68a; }
.timer.low { color: #fca5a5; }
.q-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; margin-bottom: 14px; box-shadow: var(--shadow); }
.q-text { font-weight: 600; font-size: 18px; margin-bottom: 10px; white-space: pre-wrap; }
.option { display: flex; align-items: flex-start; gap: 10px; border: 1.5px solid var(--border); border-radius: 10px; padding: 10px 12px; margin-bottom: 8px; cursor: pointer; background: #fff; }
.option input { width: auto; margin-top: 6px; }
.option.selected { border-color: var(--primary); background: #eff6ff; }
.option.correct { border-color: var(--green); background: #dcfce7; }
.option.wrong { border-color: var(--red); background: #fee2e2; }
.explain { margin-top: 8px; font-size: 15px; color: var(--muted); }
.score-box { text-align: center; background: linear-gradient(135deg, var(--green), #15803d); color: #fff; border-radius: var(--radius); padding: 24px; margin-bottom: 18px; }
.score-box h2 { color: #fff; font-size: 34px; margin: 0; }

/* অ্যাডমিন */
.admin-wrap { padding: 16px 0 40px; }
.tabs { display: flex; gap: 8px; overflow-x: auto; margin-bottom: 16px; padding-bottom: 4px; }
.tab-btn { border: 2px solid var(--primary); background: #fff; color: var(--primary); font-family: inherit; font-size: 16px; font-weight: 600; padding: 8px 16px; border-radius: 999px; cursor: pointer; white-space: nowrap; }
.tab-btn.active { background: var(--primary); color: #fff; }
.toolbar { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 12px; align-items: center; }
.toolbar select, .toolbar input { width: auto; flex: 1; min-width: 140px; }
.table-wrap { overflow-x: auto; background: #fff; border-radius: var(--radius); border: 1px solid var(--border); }
table { border-collapse: collapse; width: 100%; font-size: 15px; }
th, td { padding: 10px 12px; text-align: left; border-bottom: 1px solid var(--border); vertical-align: top; }
th { background: #eff6ff; color: var(--primary-dark); white-space: nowrap; }
.row-actions { display: flex; gap: 6px; flex-wrap: wrap; }
.pill { display: inline-block; padding: 1px 10px; border-radius: 999px; font-size: 13px; font-weight: 600; }
.pill-on { background: #dcfce7; color: #166534; }
.pill-off { background: #f3f4f6; color: #4b5563; }
.admin-list-item { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 12px 14px; margin-bottom: 10px; }
.admin-list-item h3 { font-size: 18px; margin-bottom: 4px; }
.modal-bg { position: fixed; inset: 0; background: rgba(0, 0, 0, 0.55); z-index: 100; display: flex; align-items: flex-start; justify-content: center; overflow-y: auto; padding: 16px; }
.modal { background: #fff; border-radius: var(--radius); width: 100%; max-width: 640px; padding: 18px; margin: 16px 0; }
.preview-img { max-width: 220px; border-radius: 10px; margin-bottom: 8px; }

@media (min-width: 700px) {
  .hero h1 { font-size: 40px; }
  .hero { padding: 64px 0 72px; }
}