*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: system-ui, -apple-system, sans-serif;
  background: #f7f7f8;
  color: #1a1a1a;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2rem 1rem;
}

.card {
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.08);
  padding: 2.5rem 2rem;
  width: 100%;
  max-width: 640px;
}

h1 {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.25rem;
}

.subtitle {
  color: #666;
  font-size: 0.95rem;
  margin-bottom: 1.75rem;
}

textarea {
  width: 100%;
  min-height: 140px;
  resize: vertical;
  border: 1.5px solid #d1d5db;
  border-radius: 8px;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  font-family: inherit;
  line-height: 1.5;
  color: #1a1a1a;
  background: #fafafa;
  transition: border-color 0.15s;
  outline: none;
}

textarea:focus {
  border-color: #6366f1;
  background: #fff;
}

.hint {
  font-size: 0.8rem;
  color: #999;
  margin-top: 0.4rem;
  margin-bottom: 1.25rem;
}

.error {
  font-size: 0.85rem;
  color: #dc2626;
  min-height: 1.2em;
  margin-bottom: 0.75rem;
}

.label {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: #888;
  margin-bottom: 0.6rem;
}

.buttons {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.25rem;
  border: none;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.15s, transform 0.1s;
  color: #fff;
  flex: 1;
  justify-content: center;
  min-width: 130px;
}

.btn:hover  { opacity: 0.88; }
.btn:active { transform: scale(0.97); }

.btn-perplexity { background: #20b2aa; }
.btn-chatgpt    { background: #10a37f; }

.btn img {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

footer {
  margin-top: 2.5rem;
  font-size: 0.78rem;
  color: #bbb;
  text-align: center;
}