:root {
  --blue: #2563eb;
  --blue-dark: #1d4ed8;
  --red: #dc2626;
  --green: #16a34a;
  --gray-100: #f3f4f6;
  --gray-300: #d1d5db;
  --gray-600: #4b5563;
  --gray-900: #111827;
}

* { box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  margin: 0;
  color: var(--gray-900);
  background: #fff;
  max-width: 640px;
  margin-inline: auto;
  padding: 0 1rem 4rem;
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
  padding: 1rem 0;
  border-bottom: 1px solid var(--gray-300);
  margin-bottom: 1rem;
}

nav a, nav button.link {
  color: var(--gray-600);
  text-decoration: none;
  font-size: 0.95rem;
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
}

nav a.brand {
  font-weight: 700;
  color: var(--gray-900);
  margin-right: auto;
}

h1 { font-size: 1.3rem; }
h2 { font-size: 1.05rem; color: var(--gray-600); margin-top: 2rem; }

.flash {
  padding: 0.6rem 0.9rem;
  border-radius: 6px;
  margin-bottom: 0.75rem;
  font-size: 0.9rem;
}
.flash-success { background: #dcfce7; color: #166534; }
.flash-error { background: #fee2e2; color: #991b1b; }

.task-list { list-style: none; padding: 0; margin: 0; }

.task-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--gray-100);
}

.task-item.overdue .task-title { color: var(--red); }
.task-item.done .task-title { text-decoration: line-through; color: var(--gray-600); }

.task-main { flex: 1; min-width: 0; }
.task-title { font-weight: 600; display: block; }
.task-meta { font-size: 0.8rem; color: var(--gray-600); }

.task-actions { display: flex; gap: 0.4rem; flex-shrink: 0; }

button, input[type="submit"] {
  font-size: 0.9rem;
  padding: 0.4rem 0.7rem;
  border-radius: 6px;
  border: 1px solid var(--gray-300);
  background: #fff;
  cursor: pointer;
}

button.primary, input[type="submit"].primary {
  background: var(--blue);
  border-color: var(--blue);
  color: #fff;
}
button.primary:hover { background: var(--blue-dark); }

button.danger { color: var(--red); border-color: var(--red); }
button.icon { padding: 0.35rem 0.5rem; }

form.inline { display: inline; }

.fab {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 3.2rem;
  height: 3.2rem;
  border-radius: 50%;
  background: var(--blue);
  color: #fff;
  font-size: 1.6rem;
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  box-shadow: 0 2px 8px rgba(0,0,0,0.25);
}

.field { margin-bottom: 1rem; }
.field label { display: block; font-size: 0.85rem; color: var(--gray-600); margin-bottom: 0.3rem; }
.field input, .field select, .field textarea {
  width: 100%;
  padding: 0.55rem;
  border: 1px solid var(--gray-300);
  border-radius: 6px;
  font-size: 1rem;
}

table { width: 100%; border-collapse: collapse; font-size: 0.9rem; }
th, td { text-align: left; padding: 0.5rem; border-bottom: 1px solid var(--gray-100); }

.login-box { max-width: 320px; margin: 3rem auto; }