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

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --danger: #dc2626;
  --success: #16a34a;
  --warning: #d97706;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-500: #6b7280;
  --gray-700: #374151;
  --gray-900: #111827;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--gray-50);
  color: var(--gray-900);
  line-height: 1.5;
  min-height: 100vh;
}

/* NAV */
nav {
  background: white;
  border-bottom: 1px solid var(--gray-200);
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  position: sticky;
  top: 0;
  z-index: 10;
  box-shadow: var(--shadow);
}
nav .brand { font-weight: 700; font-size: 1.1rem; color: var(--primary); text-decoration: none; display: flex; align-items: center; gap: 0.5rem; }
nav .nav-links { display: flex; gap: 1rem; align-items: center; }
nav a { color: var(--gray-700); text-decoration: none; font-size: 0.9rem; padding: 0.4rem 0.75rem; border-radius: var(--radius); transition: background 0.15s; }
nav a:hover { background: var(--gray-100); }
nav a.active { background: var(--primary); color: white; }

/* LAYOUT */
.container { max-width: 1100px; margin: 0 auto; padding: 1.5rem; }

/* CARDS */
.card {
  background: white;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

/* BUTTONS */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 1rem;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  transition: opacity 0.15s, transform 0.1s;
}
.btn:active { transform: scale(0.98); }
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-danger { background: var(--danger); color: white; }
.btn-danger:hover { opacity: 0.9; }
.btn-success { background: var(--success); color: white; }
.btn-success:hover { opacity: 0.9; }
.btn-outline { background: transparent; border: 1px solid var(--gray-200); color: var(--gray-700); }
.btn-outline:hover { background: var(--gray-100); }
.btn-sm { padding: 0.3rem 0.65rem; font-size: 0.8rem; }
.btn-warning { background: var(--warning); color: white; }
.btn-warning:hover { opacity: 0.9; }

/* TABLE */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 0.9rem; }
thead tr { background: var(--gray-50); }
th { padding: 0.75rem 1rem; text-align: left; font-weight: 600; color: var(--gray-700); border-bottom: 2px solid var(--gray-200); white-space: nowrap; }
td { padding: 0.75rem 1rem; border-bottom: 1px solid var(--gray-100); vertical-align: middle; }
tr:last-child td { border-bottom: none; }
tr:hover td { background: var(--gray-50); }

/* BADGE */
.badge { display: inline-block; padding: 0.2rem 0.6rem; border-radius: 9999px; font-size: 0.75rem; font-weight: 600; }
.badge-green { background: #dcfce7; color: #15803d; }
.badge-red { background: #fee2e2; color: #b91c1c; }
.badge-blue { background: #dbeafe; color: #1d4ed8; }

/* FORM */
.form-group { margin-bottom: 1rem; }
label { display: block; font-size: 0.875rem; font-weight: 500; color: var(--gray-700); margin-bottom: 0.35rem; }
input, textarea, select {
  width: 100%;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  font-size: 0.9rem;
  color: var(--gray-900);
  transition: border-color 0.15s, box-shadow 0.15s;
  background: white;
}
input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}
textarea { resize: vertical; min-height: 80px; }

/* MODAL */
.modal-overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.5);
  display: flex; align-items: center; justify-content: center;
  z-index: 100;
  padding: 1rem;
}
.modal-overlay.hidden { display: none; }
.modal {
  background: white;
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  width: 100%;
  max-width: 500px;
  padding: 1.5rem;
}
.modal-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; }
.modal-header h2 { font-size: 1.1rem; }
.modal-close { background: none; border: none; cursor: pointer; font-size: 1.4rem; color: var(--gray-500); }

/* LOGIN */
.login-wrap {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}
.login-card {
  background: white;
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  padding: 2.5rem;
  width: 100%;
  max-width: 380px;
}
.login-card h1 { font-size: 1.5rem; margin-bottom: 0.25rem; }
.login-card .subtitle { color: var(--gray-500); font-size: 0.9rem; margin-bottom: 1.5rem; }
.error-msg { color: var(--danger); font-size: 0.875rem; background: #fee2e2; padding: 0.6rem 0.75rem; border-radius: var(--radius); margin-bottom: 1rem; }

/* PAGE HEADER */
.page-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 1.5rem; flex-wrap: wrap; gap: 0.75rem; }
.page-header h1 { font-size: 1.4rem; }

/* STATS GRID */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 1rem; margin-bottom: 1.5rem; }
.stat-card { background: white; border-radius: var(--radius); box-shadow: var(--shadow); padding: 1.25rem; text-align: center; }
.stat-card .value { font-size: 2rem; font-weight: 700; color: var(--primary); }
.stat-card .label { font-size: 0.8rem; color: var(--gray-500); margin-top: 0.25rem; }

/* DEVICE BARS */
.device-bar-wrap { margin: 0.5rem 0; }
.device-bar-label { display: flex; justify-content: space-between; font-size: 0.85rem; margin-bottom: 0.25rem; }
.device-bar-track { background: var(--gray-100); border-radius: 9999px; height: 10px; overflow: hidden; }
.device-bar-fill { height: 100%; border-radius: 9999px; background: var(--primary); transition: width 0.4s; }

/* URL display */
.url-cell { max-width: 200px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.code-cell { font-family: monospace; font-size: 0.85rem; }
.actions-cell { display: flex; gap: 0.4rem; flex-wrap: wrap; }

/* TOAST */
.toast {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  background: var(--gray-900);
  color: white;
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius);
  font-size: 0.9rem;
  box-shadow: var(--shadow-md);
  z-index: 200;
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.25s, transform 0.25s;
  pointer-events: none;
}
.toast.show { opacity: 1; transform: translateY(0); }
.toast.error { background: var(--danger); }

/* RESPONSIVE */
@media (max-width: 640px) {
  nav .nav-links a span { display: none; }
  .page-header { flex-direction: column; align-items: flex-start; }
  td, th { padding: 0.5rem 0.6rem; }
  .actions-cell { flex-direction: column; }
  .btn-sm { width: 100%; justify-content: center; }
}