:root {
  --nav: #a9cce3;
  --primary: #2874a6;
  --primary-dark: #1b4f72;
  --surface: #ffffff;
  --line: #d6e3ec;
  --page: #f3f7fa;
}

body {
  min-height: 100vh;
  background: var(--page);
  color: #17202a;
}

.app-nav {
  background: var(--nav);
  border-bottom: 1px solid #8db7d3;
}

.app-shell {
  min-height: 100vh;
  padding: 96px 24px 48px;
}

.login-panel {
  min-height: calc(100vh - 160px);
  display: grid;
  place-items: center;
}

.panel {
  width: 100%;
  max-width: 920px;
  margin: 0 auto;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 28px;
  box-shadow: 0 10px 30px rgba(27, 79, 114, 0.08);
}

.login-panel .panel {
  max-width: 460px;
  background: var(--nav);
}

.custom-btn {
  background: var(--primary);
  border-color: var(--primary);
}

.custom-btn:hover,
.custom-btn:focus {
  background: var(--primary-dark);
  border-color: var(--primary-dark);
}

.page-heading {
  max-width: 920px;
  margin: 0 auto 28px;
}

.app-tabs {
  max-width: 920px;
  margin: 0 auto 24px;
}

.app-tabs .nav-link {
  color: var(--primary-dark);
}

.app-tabs .nav-link.active {
  font-weight: 700;
}

.operation-grid {
  max-width: 920px;
  margin: 0 auto;
  display: grid;
  gap: 22px;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.operation-button {
  min-height: 86px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 18px;
  border-radius: 8px;
  border: 1px solid var(--primary);
  background: var(--primary);
  color: white;
  font-weight: 700;
  text-decoration: none;
}

.operation-button:hover,
.operation-button:focus {
  background: var(--primary-dark);
  color: white;
}

.permissions {
  display: grid;
  gap: 8px;
}

.permissions label {
  display: block;
}

.toast-message {
  position: fixed;
  right: 24px;
  bottom: 24px;
  max-width: 420px;
  padding: 14px 16px;
  border-radius: 8px;
  background: #17202a;
  color: white;
  box-shadow: 0 10px 28px rgba(23, 32, 42, 0.25);
}

@media (max-width: 640px) {
  .app-shell {
    padding: 88px 14px 32px;
  }

  .panel {
    padding: 20px;
  }
}