body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f6f7fb;
  color: #222;
  min-height: 100vh;
  transition: background-color 0.3s, color 0.3s;
}
.dark {
  background: #121212;
  color: #eee;
}
header {
  background: #3075b2;
  color: #fff;
  padding: 15px 15px 5px 15px;
  text-align: center;
  position: relative;
  box-shadow: 0 2px 5px #8883;
}
.logo-area h1 {
  margin: 0;
  font-size: 1.75em;
}
.logo-area .since {
  font-size: 0.7em;
  color: #fad02c;
}
.logo-area .address {
  font-size: 1em;
  margin-top: 4px;
}
nav {
  margin-top: 10px;
}
nav a {
  color: #fff;
  background: #5196d6;
  margin: 0 6px;
  padding: 8px 20px;
  border-radius: 6px;
  text-decoration: none;
  font-weight: bold;
  display: inline-block;
  transition: background-color 0.2s;
}
nav a:hover {
  background: #fad02c;
  color: #3075b2;
}
.theme-toggle {
  position: absolute;
  top: 12px;
  right: 10px;
  background: #ffd700;
  border: none;
  padding: 8px 14px;
  font-weight: bold;
  font-size: 0.9em;
  border-radius: 6px;
  cursor: pointer;
}
main {
  padding: 15px 20px;
  max-width: 900px;
  margin: auto;
}
button {
  background: #276db3;
  color: #fff;
  border: none;
  border-radius: 6px;
  font-weight: bold;
  padding: 8px 16px;
  margin: 5px 5px 15px 0;
  cursor: pointer;
  font-size: 1em;
}
button:hover {
  background: #fad02c;
  color: #000;
}
input,
select,
textarea {
  font-size: 1em;
  padding: 8px 10px;
  margin: 10px 0;
  width: 100%;
  box-sizing: border-box;
}
table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 15px;
}
th,
td {
  padding: 10px;
  border: 1px solid #ccc;
  text-align: center;
}
th {
  background: #e8eefa;
  color: #276db3;
}
.dark th {
  background: #222;
  color: #ffd700;
}
.login-container {
  max-width: 400px;
  margin: 80px auto;
  background: #fff;
  padding: 35px;
  border-radius: 12px;
  box-shadow: 0 4px 40px #0003;
  text-align: center;
}
.login-container h2 {
  margin-bottom: 8px;
}
.login-container .address {
  font-weight: 600;
  color: #3177bb;
  font-size: 1.1em;
  margin-bottom: 25px;
}
.login-container #loginMsg {
  margin-top: 15px;
  color: red;
  font-weight: 600;
}