* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: Arial, sans-serif;
}

body {
  background: #ffffff;
  color: #111827;
  padding: 20px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

header {
  text-align: center;
  margin-bottom: 30px;
}

header h1 {
  font-size: clamp(2.2rem, 4vw, 3rem);
  margin-bottom: 5px;
  color: #000000;
}

header p {
  color: #9ca3af;
  font-size: 0.95rem;
}

.viewer-wrapper {
  flex: 1;
  display: flex;
  align-items: stretch;
  justify-content: center;
  width: 100%;
  max-width: 1200px;
}

.viewer {
  position: relative;
  width: 100%;
  max-width: 1100px;
  aspect-ratio: 16 / 9;
  border-radius: 18px;
  overflow: hidden;
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.45);
  background: #020617;
}

.viewer-background {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  filter: brightness(0.6);
  transform: scale(1.05);
}

.viewer-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 24px;
  cursor: pointer;
  z-index: 1;
}

.tip-title {
  font-size: clamp(1.6rem, 3.2vw, 2.4rem);
  font-weight: 700;
  color: #f9fafb;
  text-shadow: 0 3px 10px rgba(15, 23, 42, 0.9);
  max-width: 24ch;
  margin-bottom: 16px;
  line-height: 1.25;
}

.tip-details {
  font-size: 1rem;
  line-height: 1.6;
  color: #e5e7eb;
  text-shadow: 0 2px 6px rgba(15, 23, 42, 0.85);
  max-width: 36ch;
  white-space: pre-line;
}

.hint {
  margin-top: 18px;
  font-size: 0.85rem;
  color: #e5e7eb;
  opacity: 0.85;
}

.hint span {
  color: #a5b4fc;
  font-weight: 600;
}

.arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 44px;
  height: 44px;
  border-radius: 999px;
  border: none;
  background: rgba(15, 23, 42, 0.8);
  color: #e5e7eb;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 2;
  transition: background 0.15s ease, transform 0.15s ease, box-shadow 0.15s ease;
}

.arrow:hover {
  background: rgba(15, 23, 42, 1);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
  transform: translateY(-50%) scale(1.05);
}

.arrow-left {
  left: 14px;
}

.arrow-right {
  right: 14px;
}

.arrow span {
  font-size: 1.4rem;
  line-height: 1;
}

footer {
  margin-top: 24px;
  text-align: center;
  font-size: 0.9rem;
  color: #9ca3af;
}

@media (max-width: 600px) {
  body {
    padding: 14px;
  }

  .arrow {
    width: 38px;
    height: 38px;
  }

  .tip-details {
    font-size: 0.95rem;
  }
}