* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: #f4f7fb;
  color: #1f2937;
}

.container {
  min-height: 100vh;
  padding: 24px;
  display: flex;
  justify-content: center;
  align-items: flex-start;
}

.card {
  width: 100%;
  max-width: 900px;
  background: #ffffff;
  border-radius: 16px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
  padding: 32px;
}

h1 {
  margin-top: 0;
  margin-bottom: 8px;
  font-size: 28px;
  text-align: center;
}

.subtitle {
  margin-top: 0;
  margin-bottom: 24px;
  text-align: center;
  color: #6b7280;
}

.form-group {
  margin-bottom: 18px;
}

label {
  display: block;
  margin-bottom: 8px;
  font-weight: 600;
}

input {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid #cbd5e1;
  border-radius: 10px;
  font-size: 15px;
  outline: none;
  transition: 0.2s ease;
}

input:focus {
  border-color: #2563eb;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

input.invalid {
  border-color: #dc2626;
  background: #fef2f2;
}

.error-message {
  display: block;
  margin-top: 6px;
  min-height: 18px;
  color: #dc2626;
  font-size: 13px;
}

button {
  width: 100%;
  padding: 14px;
  border: none;
  border-radius: 10px;
  background: #2563eb;
  color: white;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  transition: 0.2s ease;
}

button:hover {
  background: #1d4ed8;
}

.alert {
  padding: 14px 16px;
  border-radius: 10px;
  margin-bottom: 20px;
  font-size: 15px;
}

.alert.success {
  background: #ecfdf5;
  color: #065f46;
  border: 1px solid #a7f3d0;
}

.alert.danger {
  background: #fef2f2;
  color: #991b1b;
  border: 1px solid #fecaca;
}

.table-section {
  margin-top: 32px;
}

.table-section h2 {
  margin-bottom: 14px;
}

.table-wrapper {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
}

table th,
table td {
  border: 1px solid #e5e7eb;
  padding: 12px;
  text-align: left;
  font-size: 14px;
}

table th {
  background: #eff6ff;
  font-weight: 700;
}

.empty-text {
  color: #6b7280;
  font-style: italic;
}