/* ===== Reset & Base ===== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #dbeafe;
  --color-success: #16a34a;
  --color-warning: #f59e0b;
  --color-danger: #dc2626;
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --color-border: #e2e8f0;
  --radius: 8px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --transition: 0.2s ease;
}

html {
  font-size: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen,
    Ubuntu, Cantarell, 'Helvetica Neue', sans-serif;
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.5;
  min-height: 100vh;
}

/* ===== Header ===== */
.app-header {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 0.75rem 1rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.app-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-primary);
}

.branding {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  font-style: italic;
  white-space: nowrap;
}

/* ===== Menu Toggle (mobile) ===== */
.menu-toggle {
  display: block;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 1.5rem;
  padding: 0.25rem 0.5rem;
  cursor: pointer;
  margin-top: 0.5rem;
  color: var(--color-text);
}

/* ===== Navigation ===== */
.app-nav {
  display: none;
  margin-top: 0.5rem;
}

.app-nav.open {
  display: block;
}

.nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.nav-link {
  display: block;
  padding: 0.5rem 0.75rem;
  text-decoration: none;
  color: var(--color-text);
  border-radius: var(--radius);
  font-size: 0.95rem;
  transition: background-color var(--transition), color var(--transition);
}

.nav-link:hover,
.nav-link:focus-visible {
  background-color: var(--color-primary-light);
  color: var(--color-primary-dark);
}

.nav-link.active {
  background-color: var(--color-primary);
  color: #fff;
  font-weight: 600;
}

.nav-separator {
  border-top: 1px solid var(--color-border);
  margin: 0.25rem 0;
}

/* ===== Main Content ===== */
.app-content {
  max-width: 960px;
  margin: 0 auto;
  padding: 1rem;
}

.welcome {
  text-align: center;
  padding: 3rem 1rem;
}

.welcome h2 {
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
  color: var(--color-primary);
}

.welcome p {
  color: var(--color-text-muted);
}

/* ===== Notifications ===== */
.notifications-container {
  position: fixed;
  bottom: 1rem;
  right: 1rem;
  z-index: 200;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  max-width: 360px;
}

.notification {
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  font-size: 0.9rem;
  animation: slideIn 0.25s ease;
}

.notification--info {
  background-color: var(--color-primary-light);
  color: var(--color-primary-dark);
}

.notification--success {
  background-color: #dcfce7;
  color: var(--color-success);
}

.notification--warning {
  background-color: #fef3c7;
  color: #92400e;
}

.notification--error {
  background-color: #fee2e2;
  color: var(--color-danger);
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(0.5rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Forms (shared) ===== */
.form-group {
  margin-bottom: 1rem;
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  color: var(--color-text);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 0.95rem;
  color: var(--color-text);
  background-color: var(--color-surface);
  transition: border-color var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.form-error {
  color: var(--color-danger);
  font-size: 0.8rem;
  margin-top: 0.25rem;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem 1rem;
  border: none;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color var(--transition), opacity var(--transition);
}

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

.btn-primary:hover {
  background-color: var(--color-primary-dark);
}

.btn-danger {
  background-color: var(--color-danger);
  color: #fff;
}

.btn-danger:hover {
  opacity: 0.9;
}

.btn-secondary {
  background-color: var(--color-border);
  color: var(--color-text);
}

.btn-secondary:hover {
  background-color: #cbd5e1;
}

/* ===== Cards / List Items ===== */
.card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1rem;
  margin-bottom: 0.75rem;
  box-shadow: var(--shadow-sm);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
}

.card-actions {
  display: flex;
  gap: 0.5rem;
}

/* ===== Progress Bar ===== */
.progress-bar {
  width: 100%;
  height: 0.5rem;
  background-color: var(--color-border);
  border-radius: 999px;
  overflow: hidden;
}

.progress-bar__fill {
  height: 100%;
  border-radius: 999px;
  transition: width var(--transition);
  background-color: var(--color-primary);
}

.progress-bar__fill--warning {
  background-color: var(--color-warning);
}

.progress-bar__fill--danger {
  background-color: var(--color-danger);
}

/* ===== Desktop (≥ 768px) ===== */
@media (min-width: 768px) {
  .app-header {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    padding: 0.75rem 2rem;
  }

  .menu-toggle {
    display: none;
  }

  .app-nav {
    display: block;
    margin-top: 0;
    flex: 1;
  }

  .nav-list {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 0.25rem;
  }

  .nav-separator {
    border-top: none;
    border-left: 1px solid var(--color-border);
    margin: 0 0.25rem;
    align-self: stretch;
  }

  .app-content {
    padding: 1.5rem 2rem;
  }
}