/* ===== GENERAL PAGE STYLING ===== */
body {
  margin: 0;
  padding: 0;
  text-align: center;
  font-family: "Segoe UI", sans-serif;
  background: linear-gradient(135deg, rgba(0, 0, 0, 0.9), rgba(50, 50, 50, 0.8)),
    url("https://images.unsplash.com/photo-1523275335684-37898b6baf30")
      center/cover no-repeat;
  height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: white;
}

/* ===== HEADINGS ===== */
h1 {
  font-size: clamp(1.5rem, 5vw, 3rem);
  letter-spacing: 2px;
  text-shadow: 0 0 15px rgba(255, 255, 255, 0.6);
  margin-bottom: 10px;
}
h2 {
  font-weight: normal;
  font-size: clamp(1rem, 3.5vw, 1.5rem);
  margin-bottom: 25px;
  text-shadow: 0 0 10px rgba(255, 255, 255, 0.4);
}

/* ===== BUTTON CONTAINER ===== */
.btn-container {
  display: flex;
  flex-direction: column;
  gap: 15px;
  background: rgba(255, 255, 255, 0.05);
  padding: 20px;
  border-radius: 20px;
  backdrop-filter: blur(12px);
  box-shadow: 0 0 25px rgba(0, 0, 0, 0.5);
}

/* Row layout */
.line-one,
.line-two {
  display: flex;
  gap: 15px;
  justify-content: center;
}

/* ===== BUTTONS ===== */
.btn {
  height: clamp(100px, 25vw, 150px);
  width: clamp(100px, 25vw, 150px);
  border-radius: 15%;
  border: none;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
  font-size: clamp(1.2rem, 5vw, 2rem);
  color: white;
  font-weight: bold;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  touch-action: manipulation; /* Prevent double-tap zoom on mobile */
}

.btn:hover,
.btn:active {
  transform: scale(1.05);
  box-shadow: 0 6px 20px rgba(255, 255, 255, 0.5);
}

/* ===== TILE COLORS ===== */
.red {
  background: linear-gradient(145deg, #ff4d6d, #d93c5f);
}
.yellow {
  background: linear-gradient(145deg, #ffd166, #fca311);
}
.green {
  background: linear-gradient(145deg, #06d6a0, #118ab2);
}
.purple {
  background: linear-gradient(145deg, #9d4edd, #6a4c93);
}

/* ===== FLASH EFFECTS ===== */
.flash {
  background: white !important;
  box-shadow: 0 0 30px white;
}

.userflash {
  background: limegreen !important;
  box-shadow: 0 0 30px limegreen;
}

/* ===== RESPONSIVE LAYOUT ===== */
@media (max-width: 600px) {
  body {
    padding: 10px;
    justify-content: center;
  }

  .btn-container {
    gap: 10px;
    padding: 15px;
  }

  .line-one,
  .line-two {
    gap: 10px;
  }
}