body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: linear-gradient(135deg, #0f0f0f, #1a1a1a);
  color: #fff;
  height: 100vh;
}

/* TOP BAR */
.top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background: rgba(255,255,255,0.05);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.title {
  font-size: 1.8rem;
  font-weight: bold;
}

.signup-btn {
  padding: 0.6rem 1.2rem;
  background: #ffcc00;
  border: none;
  border-radius: 10px;
  font-size: 1rem;
  cursor: pointer;
}

/* CENTER AREA */
.center-wrapper {
  height: calc(100vh - 80px);
  display: flex;
  justify-content: center;
  align-items: center;
}

/* RECTANGLE BUTTONS */
.rect-links {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  width: 400px;
}

.rect-btn {
  padding: 1.2rem;
  background: #222;
  border-radius: 16px;
  text-decoration: none;
  color: #fff;
  font-size: 1.2rem;
  text-align: center;
  border: 2px solid #333;
  box-shadow: 0 10px 25px rgba(0,0,0,0.4);
  transition: transform 0.25s ease, background 0.25s ease;
}

.rect-btn:hover {
  transform: translateY(-6px);
  background: #333;
}

/* LOCKED BUTTON */
.locked {
  opacity: 0.4;
  cursor: not-allowed;
}