/* =============================
   BASE LAYOUT
============================= */
html, body {
    margin: 0;
    padding: 0;
    height: 100%;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f6f9;
    color: #1a1a1a;
}

/* =============================
   HEADER
============================= */
header {
    position: relative;
    background-color: #002b45;
    color: rgb(0, 0, 0);
    padding: 20px;
    text-align: center;
    background-image: url("/assets/images/header.png");
    background-size: cover;
    background-position: center;
    overflow: hidden;
    min-height: 10vh;
}

header::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.4); /* white overlay with 40% opacity */
    z-index: 0;
}

header * {
    position: relative;
    z-index: 1;
}

header img {
    height: 120px;
    vertical-align: middle;
}

/* =============================
   NAVIGATION
============================= */
nav {
    background-color: #003d66;
    padding: 10px;
    text-align: center;
}

nav a {
    color: white;
    margin: 0 15px;
    text-decoration: none;
    font-weight: bold;
}

nav a:hover {
    text-decoration: underline;
}

/* =============================
   MAIN CONTENT
============================= */
main {
    padding: 20px;
    padding-bottom: 60px; /* ensures footer doesn't overlap */
}

main img {
    max-width: 100%;
    height: auto;
    display: block;
    margin-bottom: 20px;
}

.section::after {
    content: "";
    display: block;
    clear: both;
}

/* =============================
   SECTIONS
============================= */
.section {
    margin-bottom: 40px;
}

h2 {
    color: #003d66;
}

#chen {
    background-color: #e0f7fa;
    float: left;
    padding: 10px;
    border-radius: 5px;
    width: 10%;
    max-width: 100px;
    margin-right: 20px;
}

/* =============================
   FOOTER (FIXED)
============================= */
footer {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 70px;
    line-height: 60px;
    background-color: #002b45;
    color: white;
    text-align: center;
    z-index: 100;
    box-shadow: 0 -2px 5px rgba(0, 0, 0, 0.2);
}
footer p {
    margin: 20;
    font-size: 14px;
}