:root {
  --primary: #3498db;
  --success: #27ae60;
  --danger: #e74c3c;
  --dark: #2c3e50;
  --light: #f4f7f6;
}

body {
  font-family: Arial, sans-serif;
  background: var(--light);
  margin: 0;
  padding: 20px;
  color: #333;
}

.container {
  max-width: 700px;
  margin: 20px auto;
  background: #fff;
  padding: 25px;
  border-radius: 14px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.08);
}

.login-box {
  text-align: center;
}

input {
  width: 100%;
  padding: 12px;
  margin: 10px 0;
  box-sizing: border-box;
  border: 1px solid #ccc;
  border-radius: 8px;
}

button {
  width: 100%;
  padding: 14px;
  margin: 8px 0;
  border: none;
  border-radius: 8px;
  color: #fff;
  font-weight: bold;
  cursor: pointer;
}

.btn-login {
  background: var(--primary);
}

.btn-in {
  background: var(--success);
}

.btn-out {
  background: var(--danger);
}

.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.logout {
  color: var(--danger);
  text-decoration: none;
  font-weight: bold;
}

.status-box {
  background: #eef6ff;
  padding: 15px;
  border-radius: 10px;
  margin-bottom: 20px;
}

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

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 10px;
}

th, td {
  border-bottom: 1px solid #ddd;
  padding: 10px;
  text-align: left;
}

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

.error {
  background: #fdecea;
  color: #c0392b;
  padding: 10px;
  border-radius: 8px;
}

.demo {
  font-size: 14px;
  color: #666;
  margin-top: 15px;
}