/* Reset defaults */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: #f4f6f9;
  color: #333;
  line-height: 1.6;
}

/* Container */
.container {
  width: 90%;
  max-width: 1200px;
  margin: 20px auto;
  background: #fff;
  padding: 20px;
  border-radius: 10px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

/* Navigation bar */
nav {
  background-color: #2c3e50;
  padding: 10px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo {
  height: 40px;
  width: auto;
}

.site-title {
  color: #ecf0f1;
  font-size: 18px;
  font-weight: 600;
}

/* Links */
.nav-links {
  display: flex;
  gap: 20px;
}

.nav-links a {
  color: #ecf0f1;
  text-decoration: none;
  font-weight: 500;
  padding: 8px 12px;
  border-radius: 4px;
  transition: background 0.3s ease;
}

.nav-links a:hover {
  background-color: #3498db;
  color: #fff;
}

.nav-links a.active-link {
  background-color: #2980b9;
  color: #fff;
}

/* Hamburger menu for mobile */
.hamburger {
  display: none;
  flex-direction: column;
  cursor: pointer;
}

.hamburger span {
  height: 3px;
  width: 25px;
  background: #ecf0f1;
  margin: 4px 0;
  border-radius: 2px;
}

/* Buttons */
button, .btn {
  background: #3498db;
  color: #fff;
  border: none;
  padding: 10px 18px;
  border-radius: 5px;
  cursor: pointer;
  font-size: 15px;
  transition: background 0.3s ease;
}
button:hover, .btn:hover {
  background: #2980b9;
}

/* Forms */
form input, form select {
  width: 100%;
  padding: 10px;
  margin: 8px 0;
  border: 1px solid #ccc;
  border-radius: 5px;
}
form input:focus, form select:focus {
  border-color: #3498db;
  outline: none;
}

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
}
table th, table td {
  padding: 12px;
  text-align: left;
  border-bottom: 1px solid #ddd;
}
table th {
  background: #3498db;
  color: #fff;
}
table tr:hover {
  background: #f1f1f1;
}

/* Alerts */
.alert {
  padding: 12px;
  margin: 15px 0;
  border-radius: 5px;
}
.alert-success {
  background: #d4edda;
  color: #155724;
}
.alert-error {
  background: #f8d7da;
  color: #721c24;
}

/* Footer */
footer {
  background-color: #2c3e50;
  color: #ecf0f1;
  text-align: center;
  padding: 15px;
  margin-top: 30px;
  border-radius: 5px;
  font-size: 14px;
}

/* Responsive breakpoints */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    flex-direction: column;
    width: 100%;
    background-color: #2c3e50;
    margin-top: 10px;
    border-radius: 5px;
  }

  .nav-links.show {
    display: flex;
  }

  .hamburger {
    display: flex;
  }

  .site-title {
    font-size: 16px;
  }

  table, th, td {
    font-size: 14px;
  }
}

@media (max-width: 480px) {
  .logo {
    height: 30px;
  }

  .site-title {
    font-size: 14px;
  }

  .nav-links a {
    padding: 10px;
    font-size: 14px;
  }

  button, .btn {
    width: 100%;
    text-align: center;
  }

  table, th, td {
    font-size: 12px;
  }
}