:root {
  --primary: #1e5f74;
  --primary-dark: #133a49;
  --accent: #f2a541;
  --bg: #f4f7f8;
  --card-bg: #ffffff;
  --text: #223;
  --muted: #6b7a80;
  --danger: #c0392b;
  --radius: 10px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: 'Segoe UI', Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.navbar {
  background: var(--primary-dark);
  color: #fff;
  padding: 14px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
}

.navbar a { color: #fff; text-decoration: none; }
.navbar .brand { font-weight: 700; font-size: 1.2rem; }
.navbar .nav-right { display: flex; gap: 18px; align-items: center; font-size: 0.95rem; }

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px;
}

.center-screen {
  min-height: 90vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.card {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: 0 2px 10px rgba(0,0,0,0.08);
  padding: 28px;
}

.login-card { width: 100%; max-width: 380px; text-align: center; }
.login-card h1 { color: var(--primary-dark); margin-bottom: 4px; }
.login-card p.subtitle { color: var(--muted); margin-top: 0; margin-bottom: 24px; }

input[type=text], input[type=password], input[type=search], select, textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid #d5dde0;
  border-radius: 8px;
  font-size: 1rem;
  margin-bottom: 14px;
}

input[type=text]:focus, input[type=password]:focus {
  outline: none;
  border-color: var(--primary);
}

.pin-input {
  letter-spacing: 6px;
  text-align: center;
  font-size: 1.4rem;
  font-weight: 600;
}

button, .btn {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  border: none;
  padding: 12px 20px;
  border-radius: 8px;
  font-size: 1rem;
  cursor: pointer;
  text-decoration: none;
  text-align: center;
}

button:hover, .btn:hover { background: var(--primary-dark); }
.btn-accent { background: var(--accent); color: #22160a; }
.btn-danger { background: var(--danger); }
.btn-sm { padding: 6px 12px; font-size: 0.85rem; }
.btn-outline { background: transparent; border: 1px solid var(--primary); color: var(--primary); }

.error-msg {
  background: #fdecea;
  color: var(--danger);
  padding: 10px 14px;
  border-radius: 8px;
  margin-bottom: 16px;
  font-size: 0.9rem;
}

.success-msg {
  background: #e8f6ec;
  color: #1c7a3c;
  padding: 10px 14px;
  border-radius: 8px;
  margin-bottom: 16px;
  font-size: 0.9rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 20px;
  margin-top: 20px;
}

.book-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: 0 2px 8px rgba(0,0,0,0.07);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.book-cover {
  height: 160px;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.2rem;
  font-weight: 700;
  text-align: center;
  padding: 10px;
}

.book-cover img { width: 100%; height: 100%; object-fit: cover; }

.book-info { padding: 14px; flex: 1; display: flex; flex-direction: column; }
.book-info h3 { margin: 0 0 4px; font-size: 1.02rem; }
.book-info .author { color: var(--muted); font-size: 0.85rem; margin-bottom: 8px; }
.book-info .tag {
  display: inline-block;
  background: #eaf1f3;
  color: var(--primary-dark);
  font-size: 0.75rem;
  padding: 3px 8px;
  border-radius: 12px;
  margin-bottom: 10px;
  align-self: flex-start;
}
.book-actions { margin-top: auto; display: flex; gap: 8px; }

.search-bar { display: flex; gap: 10px; margin-bottom: 4px; flex-wrap: wrap; }
.search-bar input { flex: 1; min-width: 200px; margin-bottom: 0; }
.search-bar select { width: auto; margin-bottom: 0; }

table { width: 100%; border-collapse: collapse; background: #fff; border-radius: var(--radius); overflow: hidden; }
th, td { padding: 10px 14px; text-align: left; border-bottom: 1px solid #eef1f2; font-size: 0.92rem; }
th { background: var(--primary-dark); color: #fff; }
tr:hover { background: #f8fafb; }

.admin-layout { display: flex; min-height: 100vh; }
.sidebar {
  width: 220px;
  background: var(--primary-dark);
  color: #fff;
  padding: 20px 0;
  flex-shrink: 0;
}
.sidebar a {
  display: block;
  color: #cfe3e9;
  text-decoration: none;
  padding: 12px 22px;
  font-size: 0.95rem;
}
.sidebar a:hover, .sidebar a.active { background: rgba(255,255,255,0.1); color: #fff; }
.sidebar .brand { color: #fff; font-weight: 700; padding: 0 22px 20px; font-size: 1.1rem; }
.admin-main { flex: 1; padding: 26px; }

.stat-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px,1fr)); gap: 16px; margin-bottom: 24px; }
.stat-card { background: #fff; border-radius: var(--radius); padding: 18px; box-shadow: 0 2px 8px rgba(0,0,0,0.06); }
.stat-card .num { font-size: 1.8rem; font-weight: 700; color: var(--primary-dark); }
.stat-card .label { color: var(--muted); font-size: 0.85rem; }

.form-row { display: flex; gap: 14px; flex-wrap: wrap; }
.form-row > div { flex: 1; min-width: 200px; }
label { font-size: 0.85rem; color: var(--muted); display: block; margin-bottom: 4px; }

.empty-state { text-align: center; color: var(--muted); padding: 60px 20px; }

@media (max-width: 700px) {
  .admin-layout { flex-direction: column; }
  .sidebar { width: 100%; display: flex; overflow-x: auto; padding: 10px; }
  .sidebar .brand { display: none; }
  .sidebar a { padding: 10px 14px; white-space: nowrap; }
}