:root {
  --brand: #1e76d8;
  --bg: #f6f7fb;
  --card-bg: #fff;
  --border: #d5d8e1;
  --text: #222;
}

* {
  box-sizing: border-box;
}

body {
  font-family: 'Helvetica Neue', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  margin: 0;
  background: var(--bg);
  color: var(--text);
}

.site-header,
.site-footer {
  background: var(--brand);
  color: #fff;
  padding: 1rem 0;
}

.container {
  width: min(960px, 100%);
  margin: 0 auto;
  padding: 0 1.2rem;
}

main.container {
  padding: 1.5rem 1.2rem 3rem;
}

.alert {
  background: #e1f5fe;
  border-left: 4px solid var(--brand);
  padding: 0.8rem 1rem;
  margin-bottom: 1rem;
}

form {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: 0 6px 30px rgba(0, 0, 0, 0.06);
}

section {
  margin-bottom: 2rem;
}

section h2 {
  border-left: 4px solid var(--brand);
  padding-left: 0.6rem;
  font-size: 1.25rem;
}

.field-group {
  margin-bottom: 1rem;
}

.field-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.35rem;
}

input[type="text"],
input[type="number"],
textarea,
select {
  width: 100%;
  padding: 0.55rem 0.65rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  font-size: 0.95rem;
}

textarea {
  min-height: 80px;
}

.hidden {
  display: none;
}

.radio-group,
.checkbox-group,
.inline-fields {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
}

.radio-group label,
.checkbox-group label {
  font-weight: 400;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.inline-fields > * {
  flex: 1;
}

button[type="submit"] {
  background: var(--brand);
  color: #fff;
  border: none;
  border-radius: 999px;
  padding: 0.85rem 2.4rem;
  font-size: 1rem;
  cursor: pointer;
  transition: background 0.2s ease;
}

button[type="submit"]:hover {
  background: #145ba8;
}

@media (max-width: 640px) {
  form {
    padding: 1rem;
  }

  section h2 {
    font-size: 1.1rem;
  }

  .inline-fields {
    flex-direction: column;
  }
}