:root {
  --primary: #1b5fe0;
  --primary-dark: #0a2a6b;
  --sky: #5b9df9;
  --bg: #f4f7fe;
  --card: #ffffff;
  --text: #14213d;
  --muted: #6b7a99;
  --border: #e4eaf7;
  --danger: #e0334f;
  --success: #16a34a;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1b33;
    --card: #16233f;
    --text: #eef2fb;
    --muted: #93a2c2;
    --border: #24345a;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Tahoma, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.hidden { display: none !important; }
.muted { color: var(--muted); }
.error { color: var(--danger); min-height: 20px; font-size: 14px; }

/* Login */
.login-screen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(160deg, var(--primary-dark), var(--primary));
  padding: 20px;
}

.login-card {
  background: var(--card);
  border-radius: 24px;
  padding: 40px 32px;
  width: 100%;
  max-width: 380px;
  text-align: center;
  box-shadow: 0 20px 60px rgba(0,0,0,0.25);
}

.logo {
  width: 64px;
  height: 64px;
  border-radius: 18px;
  background: var(--primary);
  color: #fff;
  font-weight: 800;
  font-size: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}

.logo.small { width: 40px; height: 40px; font-size: 15px; border-radius: 12px; margin: 0; }

.login-card h1 { font-size: 20px; margin: 0 0 4px; }
.login-card p { margin: 0 0 24px; }

input[type="text"], input[type="password"] {
  width: 100%;
  padding: 14px 16px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  margin-bottom: 14px;
}

button {
  cursor: pointer;
  border: none;
  font-family: inherit;
}

#login-btn, .primary-btn {
  width: 100%;
  background: var(--primary);
  color: #fff;
  padding: 14px;
  border-radius: 14px;
  font-size: 15px;
  font-weight: 600;
}

.primary-btn { width: auto; padding: 12px 20px; }

.secondary-btn {
  background: transparent;
  color: var(--muted);
  padding: 12px 20px;
  border-radius: 14px;
  font-weight: 600;
}

/* App shell */
.app-screen { display: flex; min-height: 100vh; }

.sidebar {
  width: 240px;
  background: var(--card);
  border-left: 1px solid var(--border);
  padding: 24px 16px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; padding: 0 8px; }

nav { display: flex; flex-direction: column; gap: 6px; }

.nav-btn {
  background: transparent;
  text-align: right;
  padding: 12px 14px;
  border-radius: 12px;
  color: var(--muted);
  font-size: 15px;
  font-weight: 600;
}

.nav-btn.active { background: var(--primary); color: #fff; }

.logout {
  margin-top: auto;
  background: transparent;
  color: var(--danger);
  padding: 12px 14px;
  border-radius: 12px;
  font-weight: 600;
  text-align: right;
}

.content { flex: 1; padding: 32px; max-width: 1100px; }

.tab-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

.tab-header h2 { margin: 0; }

.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}

.device-card {
  background: var(--card);
  border-radius: 20px;
  padding: 20px;
  border: 1px solid var(--border);
  cursor: pointer;
  transition: transform 0.15s ease;
}

.device-card:hover { transform: translateY(-2px); }

.device-card .top-row { display: flex; align-items: center; justify-content: space-between; }

.status-dot { width: 10px; height: 10px; border-radius: 50%; display: inline-block; margin-left: 6px; }
.status-dot.online { background: var(--success); }
.status-dot.offline { background: #9aa6bd; }

.device-card h3 { margin: 12px 0 4px; font-size: 17px; }
.device-card .serial { color: var(--muted); font-size: 13px; margin-bottom: 12px; }

.tag-row { display: flex; gap: 6px; flex-wrap: wrap; }

.tag {
  font-size: 12px;
  background: rgba(27,95,224,0.1);
  color: var(--primary);
  padding: 4px 10px;
  border-radius: 10px;
}

.tag.unclaimed { background: rgba(224,51,79,0.1); color: var(--danger); }

.data-table { width: 100%; border-collapse: collapse; background: var(--card); border-radius: 16px; overflow: hidden; }
.data-table th, .data-table td { padding: 14px 16px; text-align: right; border-bottom: 1px solid var(--border); }
.data-table th { color: var(--muted); font-size: 13px; font-weight: 600; }

/* Modal */
.modal {
  position: fixed;
  inset: 0;
  background: rgba(10,20,50,0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  z-index: 50;
}

.modal-card {
  background: var(--card);
  border-radius: 22px;
  padding: 28px;
  width: 100%;
  max-width: 420px;
}

.modal-card.wide { max-width: 560px; }

.modal-actions { display: flex; gap: 10px; justify-content: flex-end; margin-top: 16px; }

.detail-row { display: flex; justify-content: space-between; padding: 10px 0; border-bottom: 1px solid var(--border); }
.detail-row .label { color: var(--muted); }

.ir-chip {
  display: inline-block;
  background: rgba(27,95,224,0.1);
  color: var(--primary);
  padding: 6px 12px;
  border-radius: 10px;
  font-size: 13px;
  margin: 4px 6px 0 0;
}

@media (max-width: 720px) {
  .app-screen { flex-direction: column; }
  .sidebar { width: 100%; flex-direction: row; align-items: center; }
  nav { flex-direction: row; }
  .logout { margin-top: 0; }
  .content { padding: 20px; }
}