body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f5f5f5;
  color: #111;
}

/* NAVBAR */
nav {
  background: #1f2937;
  padding: 12px 20px;
}

nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 18px;
  align-items: center;
}

nav li {
  margin: 0;
  padding: 0;
}

nav a {
  display: block;
  color: #e5e7eb;
  text-decoration: none;
  font-size: 16px;
  padding: 8px 10px;
  border-radius: 6px;
  transition: background-color 0.15s ease, color 0.15s ease;
}

nav a:hover {
  background: #374151;
  color: #ffffff;
}

/* PAGE CONTENT WRAPPER (use <div class="container"> ... </div>) */
.container {
  max-width: 800px;
  margin: 32px auto;
  padding: 24px;
  background: #ffffff;
  border-radius: 12px;
}
.container h1 {
  text-align: center;
}
.container p {
  text-align: center;
}


/* FORM */
form {
  max-width: 720px;
  margin: 18px auto 0;
  background: #ffffff;
  padding: 16px;
  border-radius: 10px;
}

label {
  display: block;
  margin-top: 12px;
  font-weight: 600;
}

input, select, button {
  width: 100%;
  box-sizing: border-box;
  padding: 10px;
  margin-top: 6px;
  border: 1px solid #d1d5db;
  border-radius: 8px;
  font-size: 16px;
  background: #ffffff;
}

button {
  margin-top: 14px;
  background: #2563eb;
  border: none;
  color: #ffffff;
  cursor: pointer;
}

button:hover {
  background: #1d4ed8;
}

/* RESULT AREA */
#result {
  max-width: 720px;
  margin: 14px auto 0;
  min-height: 20px;
}

/* RESULT CARD */
.result-card {
  margin-top: 16px;
  padding: 16px;
  border-radius: 10px;
  background: #ffffff;
  border: 1px solid #e5e7eb;
}

.result-card.valid {
  border-left: 6px solid #16a34a;
}

.result-card.invalid {
  border-left: 6px solid #dc2626;
}

.result-status {
  font-weight: 600;
  font-size: 18px;
  margin-bottom: 12px;
}

.result-row {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  border-bottom: 1px solid #f1f5f9;
}

.result-row:last-child {
  border-bottom: none;
}

.result-row span:first-child {
  color: #6b7280;
}

.result-row span:last-child {
  font-weight: 500;
}

/* HELP PAGE LIST SPACING */
ol {
  padding-left: 20px;
}

ol li {
  margin-bottom: 8px;
}

/* IMAGES (optional) */
img {
  display: block;
  max-width: 800px;
  width: 100%;
  height: auto;
  margin: 14px auto 0;
  border-radius: 10px;
}