/* ==== RESET CƠ BẢN ==== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ==== TOÀN TRANG ==== */
body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  background-color: #f9f9f9;
  color: #333;
  padding: 20px;
}

/* ==== HEADER ==== */
header {
  text-align: center;
  padding: 40px 0 20px;
}

header h1 {
  font-size: 2.5rem;
  margin-bottom: 10px;
  color: #2c3e50;
}

header p {
  font-size: 1rem;
  color: #777;
}

/* ==== THANH ĐIỀU HƯỚNG ==== */
nav {
  text-align: center;
  margin-bottom: 40px;
}

nav a {
  margin: 0 15px;
  text-decoration: none;
  color: #3498db;
  font-weight: bold;
  transition: color 0.3s;
}

nav a:hover {
  color: #1d6fa5;
}

/* ==== KHUNG CHÍNH ==== */
.container,
main {
  max-width: 900px;
  margin: 0 auto;
  background-color: #fff;
  padding: 30px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  animation: fadeIn 0.8s ease-in-out;
}

/* ==== MỤC SỞ THÍCH ==== */
.hobbies {
  margin-top: 20px;
}

.hobby-item {
  margin-bottom: 20px;
  padding-bottom: 15px;
  border-bottom: 1px solid #e0e0e0;
}

.hobby-item:last-child {
  border-bottom: none;
}

.hobby-item h2 {
  font-size: 1.4rem;
  color: #2c3e50;
  margin-bottom: 10px;
}

.hobby-item p {
  font-size: 1rem;
  color: #555;
  margin-left: 20px;
}

/* ==== FORM LIÊN HỆ ==== */
form {
  margin-top: 20px;
  text-align: left;
  display: inline-block;
  width: 100%;
}

label {
  display: block;
  margin-top: 10px;
  font-weight: bold;
  color: #2c3e50;
}

input[type="text"],
textarea {
  width: 100%;
  padding: 10px;
  margin-top: 6px;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-family: inherit;
  font-size: 1rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}

input[type="text"]:focus,
textarea:focus {
  border-color: #3498db;
  box-shadow: 0 0 5px rgba(52, 152, 219, 0.3);
  outline: none;
}

textarea {
  resize: vertical;
}

/* ==== NÚT ==== */
.btn,
input[type="submit"] {
  background-color: #3498db;
  color: white;
  border: none;
  padding: 10px 20px;
  font-size: 1rem;
  border-radius: 6px;
  cursor: pointer;
  margin-top: 15px;
  transition: background-color 0.3s;
}

.btn:hover,
input[type="submit"]:hover {
  background-color: #1d6fa5;
}

/* ==== BẢN ĐỒ ==== */
iframe {
  margin-top: 30px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

/* ==== BẢNG (TRANG KẾ HOẠCH HỌC TẬP) ==== */
table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 15px;
  font-size: 0.95rem;
}

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

th {
  background-color: #f2f2f2;
  color: #2c3e50;
}

tr:hover {
  background-color: #f9f9f9;
}

/* ==== DANH SÁCH ==== */
ul {
  text-align: left;
  display: inline-block;
  margin-top: 10px;
}

li {
  color: #555;
  margin-bottom: 5px;
}

/* ==== ẢNH VÀ TIỂU SỬ ==== */
img {
  border-radius: 10px;
  box-shadow: 0 3px 8px rgba(0,0,0,0.1);
  margin-bottom: 15px;
}

/* ==== ĐƯỜNG KẺ ==== */
hr {
  margin: 25px auto;
  border: none;
  height: 1px;
  background-color: #e0e0e0;
}

/* ==== FOOTER ==== */
footer {
  text-align: center;
  margin-top: 40px;
  color: #aaa;
  font-size: 0.9rem;
}

footer a {
  color: #3498db;
  text-decoration: none;
  transition: color 0.2s;
}

footer a:hover {
  color: #1d6fa5;
}

/* ==== HIỆU ỨNG ==== */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ==== RESPONSIVE ==== */
@media screen and (max-width: 768px) {
  header h1 {
    font-size: 2rem;
  }

  nav a {
    display: inline-block;
    margin: 5px 10px;
    font-size: 0.95rem;
  }

  .container,
  main {
    padding: 20px;
  }

  iframe {
    width: 100%;
    height: 300px;
  }
}