/* ── 字体 ── */
@font-face {
  font-family: 'MiSans';
  src: url('font/MiSans-Regular.woff2') format('woff2');
  font-weight: 400; font-style: normal; font-display: swap;
}
@font-face {
  font-family: 'MiSans';
  src: url('font/MiSans-Medium.woff2') format('woff2');
  font-weight: 500; font-style: normal; font-display: swap;
}
@font-face {
  font-family: 'MiSans';
  src: url('font/MiSans-Bold.woff2') format('woff2');
  font-weight: 700; font-style: normal; font-display: swap;
}

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

/* ── CSS 变量 ── */
:root {
  --bg:        #f2f3f5;
  --bg2:       #ebedf0;
  --bg3:       #e2e4e8;
  --card:      #ffffff;
  --ink:       #111827;
  --ink-sec:   #374151;
  --ink-faint: #6b7280;
  --accent:    #439288;
  --accent-dk: #357870;
  --border:    rgba(0,0,0,0.07);
  --border-mid:rgba(0,0,0,0.13);
  --radius:    10px;
  --max:       1080px;
  --font:      'MiSans', -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

/* ── Base ── */
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 15px;
  font-weight: 400;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }

.container {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
}

/* ── 滚动入场动画 ── */
[data-a] {
  opacity: 0;
  transform: translateY(28px) scale(0.98);
  transition:
    opacity  0.72s cubic-bezier(.16,1,.3,1),
    transform 0.82s cubic-bezier(.16,1,.3,1);
  transition-delay: var(--d, 0s);
}
[data-a].in { opacity: 1; transform: none; }

/* ── Section 公共 ── */
.section { padding: 96px 0; border-bottom: 1px solid var(--border); }
.section-dark { background: var(--bg2); }
.section-label {
  font-size: 11px; letter-spacing: .14em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 12px;
}
.section h2 {
  font-size: clamp(26px, 3.5vw, 38px);
  font-weight: 700;
  font-family: var(--font);
  letter-spacing: -.025em;
  margin-bottom: 64px;
  color: var(--ink);
  line-height: 1.2;
}

/* ── Button ── */
.btn-primary {
  display: inline-flex; align-items: center;
  background: var(--accent); color: #fff;
  font-size: 14px; font-weight: 600;
  padding: 12px 28px; border-radius: 6px;
  border: none; cursor: pointer;
  transition: background .2s, transform .15s;
}
.btn-primary:hover { background: var(--accent-dk); transform: translateY(-1px); }
.btn-primary:active { transform: translateY(0); }

/* ── Toast ── */
.toast {
  position: fixed; bottom: 32px; left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--ink); color: #fff;
  font-size: 13px; font-weight: 600;
  padding: 10px 24px; border-radius: 6px;
  opacity: 0; pointer-events: none;
  transition: opacity .25s, transform .25s;
  white-space: nowrap;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ── 表单公共 ── */
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-field { display: flex; flex-direction: column; gap: 8px; margin-bottom: 16px; }
.form-field label { font-size: 12px; color: var(--ink-faint); letter-spacing: .06em; }
.form-field input,
.form-field textarea {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--ink);
  font-size: 14px;
  padding: 12px 14px;
  font-family: inherit;
  transition: border-color .2s;
  outline: none;
  resize: vertical;
}
.form-field input:focus,
.form-field textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(67,146,136,0.12); }
.form-field input::placeholder,
.form-field textarea::placeholder { color: var(--ink-faint); }
.req { color: #e05; font-size: 12px; }

/* 调研问卷延迟注入动画 */
@keyframes surveySlideIn {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: none; }
}
.survey-extend-in > * {
  animation: surveySlideIn 0.5s cubic-bezier(.16,1,.3,1) both;
}
.survey-extend-in > *:nth-child(2) { animation-delay: 0.06s; }
.survey-extend-in > *:nth-child(3) { animation-delay: 0.12s; }
.survey-extend-in > *:nth-child(4) { animation-delay: 0.18s; }
.survey-extend-in > *:nth-child(5) { animation-delay: 0.24s; }
.survey-extend-in > *:nth-child(6) { animation-delay: 0.30s; }
.survey-extend-in > *:nth-child(7) { animation-delay: 0.36s; }