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

/* ===== BODY ===== */
body {
  font-family: Arial, Verdana, sans-serif;
  line-height: 1.5;
}

/* ===== HEADER ===== */
header {
  position: fixed;              /* fixed to top */
  top: 0;
  width: 100%;
  background-color: orange;     
  color: white;
  display: flex;
  justify-content: space-between; 
  align-items: center;
  padding: 15px 30px;
  z-index: 1000;
}

nav ul {
  list-style: none;             /* remove bullets */
  display: flex;
  gap: 20px;
}

nav a {
  color: white;                 /* white links */
  text-decoration: none;        /* no underline */
  font-family: Verdana, Arial, sans-serif; /* sans-serif nav */
  font-size: 1em;
}

/* ===== BANNER ===== */
.banner {
  margin-top: 70px;             /* space for fixed header */
  width: 100%;
  height: 200px;                /* fixed height */
  background-color: orange;     
  display: flex;
  align-items: center;
  justify-content: center;
}

.banner h1 {
  color: white;
  font-size: 2em;
  text-align: center;
}

/* ===== MAIN CONTENT ===== */
.main-content {
  max-width: 1075px;
  margin: 30px auto;
  overflow: hidden; /* clear floats */
  padding: 0 10px; /* small padding on sides */
}

/* LEFT COLUMN */
.left-column {
  float: left;
  width: calc((600 / 1075 * 100%) - 25px); /* % minus half of gutter */
  background-color: lightgreen;
  padding: 20px;
  font-family: Arial, Verdana, sans-serif;
}

.left-column h2 {
  font-family: Georgia, "Times New Roman", serif; /* serif heading */
}

/* RIGHT COLUMN */
.right-column {
  float: right;
  width: calc((400 / 1075 * 100%) - 25px); /* % minus half of gutter */
  padding: 20px;
}

.placeholder-link {
  display: block;
  width: 100%;
  height: 100px;
  margin-bottom: 15px;
  background-color: lightgray;
  text-align: center;
  line-height: 100px;
  color: black;
  text-decoration: none;
  font-weight: bold;
  border: 2px dashed #999;
}

/* ===== FOOTER ===== */
footer {
  clear: both;
  background-color: #222;
  color: white;
  text-align: center;
  padding: 20px;
  margin-top: 20px;
}

footer a {
  color: orange;
  text-decoration: underline;
}

/* ===== RESPONSIVE ===== */
@media screen and (max-width: 900px) {
  .left-column, .right-column {
    float: none;
    width: 100%;
    margin-bottom: 20px;
  }
  .banner h1 {
    font-size: 1.5em;
  }
}