:root {
  --sidebar-width: 250px;
  --primary: #1a2e4a;
  --accent: #4f8ef7;
  --sidebar-text: #8fa3bc;
  --bg: #f4f6f9;
}

* { box-sizing: border-box; }

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  margin: 0;
  color: #1e293b;
}

/* ── Sidebar ── */
.sidebar {
  position: fixed;
  top: 0; left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  background: var(--primary);
  overflow-y: auto;
  z-index: 1000;
  display: flex;
  flex-direction: column;
}

.sidebar-brand {
  padding: 20px;
  border-bottom: 1px solid rgba(255,255,255,0.07);
}

.sidebar-logo {
  width: 36px; height: 36px;
  background: var(--accent);
  border-radius: 9px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.05rem; color: #fff;
  flex-shrink: 0;
}

.sidebar-title   { color: #fff; font-weight: 700; font-size: 0.95rem; }
.sidebar-subtitle{ color: var(--sidebar-text); font-size: 0.7rem; }

.sidebar-nav { padding: 10px 0; flex: 1; }

.sidebar-section {
  padding: 16px 20px 5px;
  font-size: 0.67rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: rgba(255,255,255,0.25);
  font-weight: 600;
}

.sidebar-nav .nav-item { margin: 1px 10px; }

.sidebar-nav .nav-link {
  color: var(--sidebar-text);
  padding: 9px 12px;
  border-radius: 8px;
  display: flex; align-items: center; gap: 9px;
  transition: all 0.15s;
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
}

.sidebar-nav .nav-link i { font-size: 0.95rem; width: 18px; text-align: center; }

.sidebar-nav .nav-link:hover {
  background: rgba(255,255,255,0.07);
  color: #fff;
}

.sidebar-nav .nav-link.active {
  background: rgba(79,142,247,0.15);
  color: #fff;
}

.sidebar-nav .nav-link.active i { color: var(--accent); }

.sidebar-footer {
  padding: 14px 20px;
  border-top: 1px solid rgba(255,255,255,0.07);
}

.sidebar-footer .nav-link {
  color: #f87171;
  padding: 9px 12px;
  border-radius: 8px;
  display: flex; align-items: center; gap: 9px;
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  transition: background 0.15s;
}

.sidebar-footer .nav-link:hover { background: rgba(248,113,113,0.1); }

/* ── Layout ── */
.page-wrapper {
  margin-left: var(--sidebar-width);
  min-height: 100vh;
  display: flex; flex-direction: column;
}

.topbar {
  background: #fff;
  border-bottom: 1px solid #e8ecf1;
  padding: 0 28px;
  height: 60px;
  display: flex; align-items: center; justify-content: space-between;
  position: sticky; top: 0; z-index: 100;
}

.topbar-title { font-weight: 700; font-size: 1rem; color: #1e293b; }

.topbar-user {
  display: flex; align-items: center; gap: 9px;
  font-size: 0.85rem; color: #64748b;
}

.topbar-avatar {
  width: 32px; height: 32px;
  background: var(--accent);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: 0.8rem; font-weight: 700;
}

.content-wrap { padding: 28px; flex: 1; }

/* ── Stat cards ── */
.stat-card {
  background: #fff;
  border-radius: 12px;
  padding: 20px 22px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
  border: 1px solid #eef1f6;
  display: flex; align-items: center; gap: 16px;
}

.stat-icon {
  width: 50px; height: 50px;
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.35rem;
}

.stat-icon.blue  { background: #eff6ff; color: #3b82f6; }
.stat-icon.red   { background: #fef2f2; color: #ef4444; }
.stat-icon.amber { background: #fffbeb; color: #f59e0b; }
.stat-icon.green { background: #f0fdf4; color: #22c55e; }

.stat-number { font-size: 1.9rem; font-weight: 800; line-height: 1; color: #1e293b; }
.stat-label  { font-size: 0.78rem; color: #94a3b8; margin-top: 3px; }

/* ── Data card / tables ── */
.data-card {
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
  border: 1px solid #eef1f6;
  overflow: hidden;
}

.data-card .card-header {
  background: #fff;
  border-bottom: 1px solid #f1f4f9 !important;
  padding: 14px 22px;
  display: flex; align-items: center; justify-content: space-between;
}

.data-card .card-header h6 { margin: 0; font-weight: 700; font-size: 0.88rem; color: #1e293b; }

.data-card table { margin: 0; }

.data-card table th {
  font-size: 0.7rem !important;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: #94a3b8 !important;
  font-weight: 600 !important;
  background: #fafbfd !important;
  padding: 11px 22px !important;
  border-top: none !important;
}

.data-card table td {
  padding: 12px 22px !important;
  vertical-align: middle !important;
  font-size: 0.875rem;
  border-color: #f1f4f9 !important;
  color: #334155;
}

/* ── Form card ── */
.form-card {
  background: #fff;
  border-radius: 12px;
  padding: 20px 22px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
  border: 1px solid #eef1f6;
  margin-bottom: 22px;
}

.form-card h6 { font-weight: 700; font-size: 0.88rem; margin-bottom: 14px; color: #1e293b; }

.form-control, .form-select {
  font-size: 0.875rem;
  border-color: #dde3ed;
  border-radius: 8px;
  padding: 9px 13px;
}

.form-control:focus, .form-select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(79,142,247,0.1);
}

.input-group-text {
  background: #f8fafc;
  border-color: #dde3ed;
  color: #94a3b8;
}

/* ── Buttons ── */
.btn { border-radius: 8px; font-size: 0.875rem; font-weight: 500; padding: 9px 18px; }
.btn-sm { padding: 5px 12px; font-size: 0.8rem; }
.btn-primary { background: var(--accent); border-color: var(--accent); }
.btn-primary:hover { background: #3b7de8; border-color: #3b7de8; }

/* ── Badges ── */
.badge-status {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 3px 9px; border-radius: 20px;
  font-size: 0.72rem; font-weight: 600;
}

.badge-online   { background: #dcfce7; color: #15803d; }
.badge-offline  { background: #f1f5f9; color: #64748b; }
.badge-removed  { background: #fee2e2; color: #991b1b; }

.alert { border-radius: 10px; font-size: 0.875rem; }

/* ── Login ── */
.login-page {
  background: linear-gradient(135deg, #1a2e4a 0%, #2d6a9f 100%);
  min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  padding: 24px;
}

.login-box {
  background: #fff;
  border-radius: 18px;
  padding: 40px 42px;
  width: 100%; max-width: 420px;
  box-shadow: 0 20px 50px rgba(0,0,0,0.25);
}

.login-icon {
  width: 56px; height: 56px;
  background: linear-gradient(135deg, #1a2e4a 0%, #4f8ef7 100%);
  border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem; color: #fff;
  margin: 0 auto 20px;
}

.login-box h3 {
  font-size: 1.3rem; font-weight: 800;
  text-align: center; color: #1e293b; margin-bottom: 4px;
}

.login-sub { text-align: center; color: #94a3b8; font-size: 0.82rem; margin-bottom: 26px; }
.login-box .form-label { font-size: 0.82rem; font-weight: 600; color: #475569; }

/* ── Landing ── */
.hero {
  background: linear-gradient(135deg, #1a2e4a 0%, #224878 60%, #2d6a9f 100%);
  min-height: 100vh;
  display: flex; flex-direction: column;
  position: relative; overflow: hidden;
}

.hero::before {
  content: ''; position: absolute; inset: 0;
  background-image:
    radial-gradient(circle at 20% 50%, rgba(79,142,247,0.15) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(79,142,247,0.1) 0%, transparent 40%);
}

.hero-nav {
  position: relative; z-index: 2;
  padding: 22px 48px;
  display: flex; align-items: center; justify-content: space-between;
}

.hero-content {
  position: relative; z-index: 2;
  flex: 1; display: flex; align-items: center; justify-content: center;
  text-align: center; padding: 0 24px 60px;
}

.feature-card {
  background: #fff;
  border-radius: 12px;
  padding: 28px 24px;
  border: 1px solid #eef1f6;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
  height: 100%;
}

.feature-icon {
  width: 50px; height: 50px;
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.3rem; margin-bottom: 14px;
}

/* ── Tablet (768px – 1024px): narrower sidebar, always visible ── */
@media (max-width: 1024px) and (min-width: 768px) {
  :root { --sidebar-width: 220px; }
  .topbar { padding: 0 20px; }
  .content-wrap { padding: 20px; }
}

/* ── Phone (≤ 767px): hide sidebar, full-width layout, bottom nav ── */
@media (max-width: 767px) {
  .sidebar { display: none !important; }        /* sidebar replaced by bottom nav */
  .page-wrapper { margin-left: 0; }
  .topbar { padding: 0 16px; }
  .content-wrap { padding: 14px; padding-bottom: 74px; } /* space for bottom nav */
  body { overflow-x: hidden; }

  .stat-number { font-size: 1.5rem; }
  .stat-card { padding: 14px 16px; gap: 12px; }

  /* Tables scroll horizontally on narrow screens */
  .data-card .table-responsive { overflow-x: auto; -webkit-overflow-scrolling: touch; }

  /* Stack the APK download card on small screens */
  .apk-card { flex-direction: column !important; align-items: flex-start !important; }

  .form-card { padding: 16px; }
  .login-box { padding: 28px 20px; }
  .hero-nav  { padding: 18px 20px; }
}

/* ── Very small phones (≤ 480px) ── */
@media (max-width: 480px) {
  .topbar-title { font-size: 0.88rem; }
  .stat-icon { width: 42px; height: 42px; font-size: 1.1rem; }
  .data-card .card-header { padding: 12px 16px; flex-wrap: wrap; gap: 8px; }
  .data-card table th,
  .data-card table td { padding: 10px 12px !important; }
  .btn { padding: 8px 14px; font-size: 0.82rem; }
}

/* ── Mobile bottom navigation bar ── */
.mobile-nav { display: none; }

@media (max-width: 767px) {
  .mobile-nav {
    display: flex;
    position: fixed;
    bottom: 0; left: 0; right: 0;
    height: 62px;
    background: var(--primary);
    z-index: 1000;
    border-top: 1px solid rgba(255,255,255,0.08);
    box-shadow: 0 -2px 16px rgba(0,0,0,0.18);
  }

  .mobile-nav-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 3px;
    color: var(--sidebar-text);
    text-decoration: none;
    font-size: 0.6rem;
    font-weight: 600;
    padding: 8px 2px;
    transition: color 0.15s;
    -webkit-tap-highlight-color: transparent;
    letter-spacing: 0.01em;
  }

  .mobile-nav-item i { font-size: 1.2rem; line-height: 1; }
  .mobile-nav-item:hover  { color: #fff; }
  .mobile-nav-item.active { color: #fff; }
  .mobile-nav-item.active i { color: var(--accent); }
  .mobile-nav-logout { color: #f87171; }
  .mobile-nav-logout:hover { color: #fca5a5; }
}