body {
    margin: 0;
    padding: 0;
    height: 100vh;
    display: flex;
    flex-direction: column;
}
.main-menu {
  display: flex;
  justify-content: flex-end;
  background-color: #f5f5f5;
  padding: 20px 40px;
  border-bottom: 1px solid #ddd;
}

.main-menu a {
    position: relative;
    margin-left: 25px;
    font-family: Roboto, sans-serif;
    font-size: 18px;
    color: #333;
    text-decoration: none;
    transition: color 0.3s ease;
}
.img {
    width: 50px;
    height: 50px;
    float: left;
}
/* hiệu ứng underline chạy mượt */
.main-menu a::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: -6px;
    width: 0;
    height: 2px;
    background: steelblue;
    transition: width 0.3s ease;
}

.main-menu a:hover {
    color: steelblue;
}

.main-menu a:hover::after {
    width: 100%;
}
section {
    flex: 1; /* mỗi section chiếm đều không gian */
    display: flex;
    justify-content: center;
    align-items: center;
    border-bottom: 1px solid #ccc;
}
.About-box, .Skill-box, .Education-box, .Contacts-box {
    display: block;
    width: 400px;
    margin: 50px auto;
    padding: 20px;
    background: #f9f9f9;
    border-radius: 20px;
    text-align: center;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    font-family: Roboto, sans-serif;
}
.About-box img {
    width: 150px;
    height: 150px;
    border-radius: 50%; /* avatar tròn */
    object-fit: cover;
    margin-bottom: 15px;
}

.About-box h2, .Skill-box h2, .Education-box h2, .Contacts-box h2, .Project-box h2 {
    color: #333;
    margin-bottom: 10px;
}
.About-box p, .Skill-box p, .Education-box p, .Contacts-box p, .Project-box p {
    max-width: 600px;
    font-size: 18px;
    line-height: 1.6;
}
/* Progress bar cho skill */
.skill-item {
    display: block;
    margin-bottom: 15px;
    text-align: left;
}

.skill-item span {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
    color: #333;
    text-align: center;
}

.bar {
    background: #eee;
    border-radius: 8px;
    overflow: hidden;
    height: 12px;
    margin-bottom: 10px;
    margin-top: 10px;
}

.progress {
    background: #4a6477;
    height: 100%;
    border-radius: 8px;
}
.Education-box a, .Contacts-box a, .Projects-box a {
    color: #0077cc;
    text-decoration: none;
}
/*Social Media*/
.social-media img {
    width: 50px;
    height: 50px;
    transition: all 0.3s ease; /* cho mượt */
}
.social-media img:hover {
    transform: scale(1.1);
    box-shadow: 0 0 10px rgba(0,0,0,0.2);
}
.footer {
    text-align: center;
}
.footer p {
    color: #fff;
    background-color: #333;
    padding: 20px 30px;
}
#Projects h2 {
    text-align: center;
    margin-bottom: 30px;
    font-size: 28px;
    color: #333;
    font-family: Roboto, sans-serif;
}
.Projects-box {
    display: block;
    gap: 20px;
    width: 400px;
    max-height: 700px;   /* container co giãn, không bị méo */
    margin: 0 auto;     /* căn giữa container */
    padding: 20px;
    background: #f9f9f9;
    border-radius: 20px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    text-align: center;
}
.Projects-box a {
    font-size: 20px;
    display: block;
}