* { margin: 0; padding: 0; box-sizing: border-box; }
html, body {
  height: 100%;
  background: #0f1a2e;
  color: white;
  font-family: Arial, sans-serif;
}
body.panel-active { overflow: hidden; }
#menu {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px 20px;
}
h1 {
  font-size: 28px;
  font-weight: bold;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: #aaa;
  margin-bottom: 32px;
}
nav {
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: 100%;
  max-width: 320px;
}
nav button {
  display: block;
  padding: 16px 24px;
  background: #1c2a44;
  border: 1px solid #2c3e60;
  border-radius: 6px;
  color: white;
  font-family: inherit;
  font-size: 18px;
  text-align: center;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}
nav button:hover {
  background: #2c3e60;
  border-color: #4a6088;
}
#panel {
  width: 100vw;
  height: 100vh;
  display: none;
  gap: 0;
}
#panel.active { display: grid; }
#panel > svg { width: 100%; height: 100%; display: block; min-width: 0; min-height: 0; }
#back {
  position: fixed;
  top: 12px;
  left: 12px;
  padding: 8px 14px;
  background: #1c2a44;
  border: 1px solid #2c3e60;
  border-radius: 6px;
  color: white;
  font: inherit;
  font-size: 14px;
  cursor: pointer;
  display: none;
  z-index: 10;
  transition: background 0.15s, border-color 0.15s;
}
#back:hover { background: #2c3e60; border-color: #4a6088; }
#back.active { display: block; }