ai {
  --c-black: #1a1a1a;
  --c-white: #ffffff;
  --c-gray: #666;
  --c-blue: #00a8ff;
  --c-pink: #ff6b9d;
  --c-green: #00e676;
  display: block;
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
  font-family: 'Noto Sans SC', 'PingFang SC', sans-serif;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-black);
  background: var(--c-white);
  position: relative;
}

ai::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    repeating-linear-gradient(0deg, transparent, transparent 2px, rgba(0,0,0,0.03) 2px, rgba(0,0,0,0.03) 4px),
    repeating-linear-gradient(90deg, transparent, transparent 2px, rgba(0,0,0,0.03) 2px, rgba(0,0,0,0.03) 4px);
  pointer-events: none;
  z-index: 0;
}

ai > * {
  position: relative;
  z-index: 1;
}

ai hd {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin: 0 0 30px 0;
  padding: 20px 0;
  border-bottom: 4px solid var(--c-black);
  position: relative;
}

ai hd::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--c-blue), var(--c-pink), var(--c-green));
}

ai hd .ch {
  display: block;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 3px;
  color: var(--c-gray);
  margin: 0 0 12px 0;
  text-transform: uppercase;
}

ai hd .ti {
  display: block;
  font-size: 38px;
  font-weight: 900;
  letter-spacing: -1px;
  color: var(--c-black);
  text-shadow: 
    3px 3px 0 var(--c-blue),
    6px 6px 0 var(--c-pink);
  font-family: 'Impact', 'STHeiti', sans-serif;
  text-align: center;
  line-height: 1.3;
  max-width: 700px;
  word-break: keep-all;
  word-wrap: break-word;
}

ai tm {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  background: var(--c-white);
  padding: 14px 18px;
  border: 3px solid var(--c-black);
  margin: 0 0 20px 0;
  position: relative;
}

ai tm::before {
  content: '';
  position: absolute;
  top: -6px;
  left: -6px;
  right: -6px;
  bottom: -6px;
  border: 2px dashed var(--c-blue);
  pointer-events: none;
}

ai tm .l,
ai tm .r {
  flex: 1;
}

ai tm p {
  margin: 0 0 6px 0;
  font-size: 13px;
  color: var(--c-black);
  font-weight: 500;
}

ai tm p:first-child {
  font-weight: 700;
  font-size: 14px;
  color: var(--c-black);
  border-bottom: 2px solid var(--c-black);
  padding-bottom: 4px;
  margin-bottom: 8px;
}

ai .d {
  font-size: 13px;
  color: var(--c-gray);
  margin: 0 0 20px 0;
  padding: 10px 14px;
  background: var(--c-white);
  border-left: 4px solid var(--c-green);
  font-style: italic;
  position: relative;
}

ai .d::before {
  content: '▶';
  position: absolute;
  left: -2px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--c-green);
  font-size: 8px;
}

ai article {
  background: var(--c-white);
  padding: 24px;
  margin: 0 0 24px 0;
  border: 3px solid var(--c-black);
  box-shadow: 8px 8px 0 rgba(0,0,0,0.1);
  position: relative;
}

ai article::before {
  content: '';
  position: absolute;
  top: 12px;
  right: 12px;
  width: 40px;
  height: 40px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'%3E%3Cellipse cx='50' cy='30' rx='45' ry='25' fill='none' stroke='%2300a8ff' stroke-width='3'/%3E%3Cellipse cx='50' cy='32' rx='40' ry='22' fill='none' stroke='%2300a8ff' stroke-width='2'/%3E%3Cpath d='M30 50 Q35 45 40 50' fill='none' stroke='%2300a8ff' stroke-width='2'/%3E%3Cpath d='M60 50 Q65 45 70 50' fill='none' stroke='%2300a8ff' stroke-width='2'/%3E%3C/svg%3E");
  background-size: contain;
  opacity: 0.3;
}

ai article p {
  margin: 0 0 16px 0;
  text-indent: 2em;
}

ai article p:first-child {
  text-indent: 0;
}

ai article p:first-child::first-letter {
  float: left;
  font-size: 72px;
  line-height: 60px;
  font-weight: 900;
  margin: 0 10px 0 0;
  color: var(--c-white);
  background: var(--c-black);
  padding: 8px 12px;
  border: 3px solid var(--c-black);
  box-shadow: 4px 4px 0 var(--c-pink);
}

ai details {
  background: var(--c-white);
  border: 3px solid var(--c-black);
  margin: 0 0 16px 0;
  position: relative;
}

ai details::after {
  content: '';
  position: absolute;
  top: 4px;
  left: 4px;
  right: -4px;
  bottom: -4px;
  border: 2px solid var(--c-black);
  pointer-events: none;
  z-index: -1;
}

ai details summary {
  padding: 12px 16px;
  cursor: pointer;
  font-weight: 700;
  font-size: 15px;
  color: var(--c-black);
  background: var(--c-white);
  border-bottom: 3px solid var(--c-black);
  transition: all 0.2s;
  list-style: none;
  position: relative;
}

ai details summary::-webkit-details-marker {
  display: none;
}

ai details summary::before {
  content: '▼';
  display: inline-block;
  margin-right: 8px;
  font-size: 10px;
  transition: transform 0.2s;
  color: var(--c-black);
  font-weight: 900;
}

ai details:not([open]) summary::before {
  transform: rotate(-90deg);
}

ai details summary:hover {
  background: var(--c-blue);
  color: var(--c-white);
}

ai details summary:hover::before {
  color: var(--c-white);
}

ai details p {
  padding: 8px 16px;
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  border-bottom: 1px solid var(--c-black);
}

ai details p:last-child {
  border-bottom: none;
}

ai details strong {
  color: var(--c-black);
  font-weight: 700;
  background: linear-gradient(transparent 60%, var(--c-green) 60%);
  padding: 0 4px;
}

ai opts {
  display: grid;
  gap: 12px;
  margin: 24px 0 0 0;
}

ai opts o {
  display: block;
  padding: 14px 18px;
  background: var(--c-white);
  border: 3px solid var(--c-black);
  cursor: pointer;
  transition: all 0.2s;
  font-size: 15px;
  font-weight: 600;
  position: relative;
}

ai opts o::before {
  content: '';
  position: absolute;
  top: -6px;
  left: -6px;
  right: 100%;
  bottom: -6px;
  background: var(--c-black);
  transition: right 0.3s;
  z-index: -1;
}

ai opts o:hover {
  color: var(--c-white);
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 var(--c-black);
}

ai opts o:hover::before {
  right: -6px;
}

ai opts o.sp {
  border-color: var(--c-pink);
  border-width: 4px;
  background: linear-gradient(135deg, var(--c-white) 0%, rgba(255,107,157,0.1) 100%);
}

ai opts o.sp::after {
  content: '💭';
  position: absolute;
  right: 14px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
}

ai opts o.sp:hover {
  box-shadow: 6px 6px 0 var(--c-pink);
}

@media (max-width: 600px) {
  ai {
    padding: 16px;
    font-size: 14px;
  }
  
  ai hd .ch {
    font-size: 16px;
  }
  
  ai hd .ti {
    font-size: 28px;
    text-shadow: 
      2px 2px 0 var(--c-blue),
      4px 4px 0 var(--c-pink);
  }
  
  ai tm {
    flex-direction: column;
    gap: 12px;
  }
  
  ai article {
    padding: 18px;
  }
  
  ai article p:first-child::first-letter {
    font-size: 56px;
    line-height: 48px;
  }
}