.alert-box {
  padding: 15px;
  margin: 20px 0;
  border: 1px solid #ccc;
  border-left: 6px solid #ccc;
  border-radius: 4px;
  background-color: #f9f9f9;
}

.warning {
  color: #856404;
  background-color: #fff3cd;
  border-color: #ffeeba;
  border-left-color: #ffc107;
}

body {
  margin: 0;
  padding: 0;
  background-color: #f4f6f8;
  font-family: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', sans-serif;
  color: #333;
}


header {
  position: sticky;
  top: 0;          
  z-index: 100;
  background-color: #1e3f35;
  color: #f5f5f5;
  padding: 20px 15px;
  text-align: center;
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
  border-bottom: 5px solid #8b5a2b;
}

header h1 {
  margin: 0 0 6px 0;
  font-size: 1.4rem;
  letter-spacing: 0.03em;
}

header p {
  margin: 0;
  font-size: 0.85rem;
  opacity: 0.85;
}

main {
  max-width: 500px;
  margin: 30px auto;
  padding: 24px;
  background: #ffffff;
  border-radius: 10px;
  box-shadow: 0 6px 20px rgba(0,0,0,0.04);
}


button {
  display: block;
  width: 100%;
  max-width: 360px;
  margin: 14px auto;
  padding: 12px 18px;
  font-size: 0.95rem;
  font-weight: bold;
  color: #ffffff;
  background: linear-gradient(135deg, #2b6cb0 0%, #1a365d 100%);
  border: none;
  border-radius: 6px;
  box-shadow: 3px 3px 0px #0f233c;
  cursor: pointer;
  transition: transform 0.1s ease, box-shadow 0.1s ease, filter 0.2s ease;
}

button:hover {
  filter: brightness(1.1);
}

button:active {
  transform: translate(3px, 3px);
  box-shadow: none;
}

div button {
  background: linear-gradient(135deg, #dd6b20 0%, #7b341e 100%);
  box-shadow: 3px 3px 0px #4a1d12;
}

br {
  display: none;
}