body {
  font-family: 'Segoe UI', Arial, sans-serif;
  background: linear-gradient(135deg, #181824 0%, #23234a 100%);
  color: #f3f3f3;
  margin: 0;
  padding: 0;
  min-height: 100vh;
}

.main-container {
  max-width: 420px;
  margin: 3em auto;
  background: rgba(34, 34, 68, 0.97);
  border-radius: 16px;
  box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
  padding: 2.5em 2em 2em 2em;
}

h2, h3 {
  color: #a78bfa;
  margin-top: 0;
  letter-spacing: 1px;
}

form {
  margin: 1.5em 0 0.5em 0;
}

input, textarea {
  width: 100%;
  margin-bottom: 1.2em;
  padding: 0.75em;
  border-radius: 8px;
  border: 1px solid #444;
  background: #23234a;
  color: #f3f3f3;
  font-size: 1em;
  transition: border 0.2s;
}
input:focus, textarea:focus {
  border: 1.5px solid #a78bfa;
  outline: none;
}

button {
  background: linear-gradient(90deg, #6c63ff 0%, #a78bfa 100%);
  color: #fff;
  border: none;
  padding: 0.7em 2em;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
  font-size: 1em;
  box-shadow: 0 2px 8px rgba(108, 99, 255, 0.15);
  transition: background 0.2s, transform 0.1s;
}
button:hover {
  background: linear-gradient(90deg, #a78bfa 0%, #6c63ff 100%);
  transform: translateY(-2px) scale(1.03);
}

.error {
  color: #ff6b6b;
  background: #2d1a1a;
  border-left: 4px solid #ff6b6b;
  padding: 0.7em 1em;
  border-radius: 6px;
  margin-bottom: 1.2em;
}

.note-content, .assistant-result {
  background: #23234a;
  padding: 1.2em;
  border-radius: 10px;
  margin-top: 1.2em;
  box-shadow: 0 2px 8px rgba(108, 99, 255, 0.08);
  font-size: 1.08em;
  word-break: break-word;
}

a {
  color: #a78bfa;
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s;
}
a:hover {
  color: #fff;
  text-decoration: underline;
}

ul {
  list-style: none;
  padding: 0;
}
li {
  margin-bottom: 0.7em;
}

.ctf-header {
  text-align: center;
  margin-bottom: 2em;
}

.ctf-nav {
  display: flex;
  justify-content: space-between;
  margin-bottom: 1.5em;
}

.ctf-btn-link {
  background: none;
  border: none;
  color: #a78bfa;
  font-size: 1em;
  cursor: pointer;
  text-decoration: underline;
  padding: 0;
  margin: 0 0.5em;
}
.ctf-btn-link:hover {
  color: #fff;
}

@media (max-width: 600px) {
  .main-container {
    max-width: 98vw;
    padding: 1em 0.5em;
  }
  h2, h3 {
    font-size: 1.2em;
  }
  button {
    width: 100%;
  }
}