:root {
  --primary: #2c3e50;
  --accent: #2980b9;
  --danger: #c0392b;
  --bg: #f4f6f8;
  --card: #ffffff;
  --border: #dfe4ea;
}

* { box-sizing: border-box; }

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

header {
  padding: 18px 24px;
  background: var(--card);
  border-bottom: 1px solid var(--border);
}
header h1 { margin: 0; font-size: 1.4rem; }
.hint { color: #6b7785; font-size: 0.9rem; margin: 8px 0 0; }

.header-row {
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 10px;
}
.auth { display: flex; align-items: center; gap: 10px; }
.avatar { width: 32px; height: 32px; border-radius: 50%; }
.uname { font-weight: 600; font-size: 0.9rem; }
.btn-link {
  text-decoration: none; padding: 8px 14px; border-radius: 8px;
  font-size: 0.9rem; font-weight: 600; color: var(--primary); background: #e1e6eb;
}
.btn-link.primary { background: var(--accent); color: #fff; }

#calendar {
  max-width: 1100px;
  margin: 20px auto;
  padding: 0 16px;
}

/* Modal */
.overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.45);
  display: flex; align-items: center; justify-content: center;
  padding: 16px; z-index: 1000;
}
.overlay.hidden { display: none; }
.modal {
  background: var(--card);
  border-radius: 12px;
  padding: 24px;
  width: 100%; max-width: 420px;
  box-shadow: 0 10px 40px rgba(0,0,0,0.2);
}
.modal h2 { margin-top: 0; }
.slot-label {
  background: #eef3f8; border-radius: 8px; padding: 8px 12px;
  font-weight: 600; color: var(--accent); text-transform: capitalize;
}

form label {
  display: block; margin: 14px 0 4px; font-size: 0.9rem; font-weight: 600;
}
form input {
  width: 100%; padding: 10px 12px;
  border: 1px solid var(--border); border-radius: 8px; font-size: 1rem;
}
form input:focus { outline: 2px solid var(--accent); border-color: var(--accent); }

.actions {
  display: flex; gap: 10px; justify-content: flex-end; margin-top: 20px;
}
button {
  padding: 10px 18px; border: none; border-radius: 8px;
  font-size: 1rem; font-weight: 600; cursor: pointer;
  background: var(--accent); color: #fff;
}
button:hover { filter: brightness(0.95); }
button:disabled { opacity: 0.6; cursor: default; }
button.secondary { background: #e1e6eb; color: var(--primary); }
button.danger { background: var(--danger); color: #fff; }

.error {
  background: #fdecea; color: var(--danger);
  border-radius: 8px; padding: 10px 12px; margin-top: 14px; font-size: 0.9rem;
}
.error.hidden, .hidden { display: none; }

a { color: var(--accent); word-break: break-all; }

/* Stránka zrušení */
.centered {
  min-height: 100vh; display: flex; align-items: center; justify-content: center;
  padding: 16px;
}
.card {
  background: var(--card); border-radius: 12px; padding: 32px;
  max-width: 480px; box-shadow: 0 6px 24px rgba(0,0,0,0.1); text-align: center;
}
.error-text { color: var(--danger); }