:root {
  --ink: #1a2230;
  --mute: #6b7789;
  --line: rgba(40, 60, 90, 0.12);
  --card: rgba(255, 255, 255, 0.72);
  --acc: #3d7ea6;
  --acc-deep: #2b5f80;
  --warm: #f3d9a4;
  --bg0: #e8f2fb;
  --bg1: #f7f3ea;
  --radius: 22px;
  --font: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --display: "Songti SC", "STSong", "Songti TC", "Noto Serif SC", serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  color: var(--ink);
  background: linear-gradient(160deg, var(--bg0), #fff 42%, var(--bg1));
  position: relative;
}

.atmosphere {
  pointer-events: none;
  position: fixed;
  inset: 0;
  background:
    radial-gradient(42vw 42vw at 78% 12%, rgba(255, 214, 150, 0.55), transparent 60%),
    radial-gradient(36vw 36vw at 12% 70%, rgba(180, 220, 255, 0.45), transparent 65%);
  z-index: 0;
}

.top, main, .foot { position: relative; z-index: 1; }

.top {
  max-width: 980px;
  margin: 0 auto;
  padding: 22px 22px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: inherit;
}
.brand-logo {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  object-fit: cover;
  box-shadow: 0 6px 18px rgba(40, 70, 110, 0.12);
}
.brand-name {
  font-family: var(--display);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}
.top nav { display: flex; gap: 18px; }
.top a {
  color: var(--mute);
  text-decoration: none;
  font-size: 0.95rem;
}
.top a:hover { color: var(--ink); }

.hero {
  max-width: 980px;
  margin: 0 auto;
  padding: min(14vh, 120px) 22px 64px;
}
.eyebrow {
  margin: 0 0 14px;
  color: var(--mute);
  letter-spacing: 0.08em;
  font-size: 0.85rem;
}
.hero h1 {
  margin: 0;
  font-family: var(--display);
  font-size: clamp(2.8rem, 8vw, 4.6rem);
  font-weight: 700;
  line-height: 1.05;
}
.lead {
  margin: 22px 0 0;
  max-width: 28em;
  font-size: clamp(1.05rem, 2.4vw, 1.25rem);
  line-height: 1.7;
  color: #334155;
}
.cta-row {
  margin-top: 34px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  appearance: none;
  border: none;
  border-radius: 999px;
  padding: 12px 22px;
  font: inherit;
  font-size: 0.98rem;
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.btn.primary {
  background: linear-gradient(145deg, var(--acc), var(--acc-deep));
  color: #fff;
  box-shadow: 0 10px 28px rgba(43, 95, 128, 0.25);
}
.btn.primary:hover { filter: brightness(1.05); }
.btn.primary:disabled { opacity: 0.55; cursor: wait; }
.btn.ghost {
  background: rgba(255,255,255,0.55);
  color: var(--ink);
  border: 1px solid var(--line);
}

.about, .feedback {
  max-width: 980px;
  margin: 0 auto;
  padding: 28px 22px 72px;
}
.about h2, .feedback h2 {
  margin: 0;
  font-family: var(--display);
  font-size: clamp(1.6rem, 3.5vw, 2.1rem);
}
.sub {
  margin: 12px 0 0;
  color: var(--mute);
  max-width: 36em;
  line-height: 1.65;
}
.points {
  list-style: none;
  margin: 36px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}
.points li {
  background: var(--card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.points strong { font-size: 1.05rem; }
.points span { color: var(--mute); line-height: 1.5; font-size: 0.95rem; }
.disclaimer {
  margin-top: 28px;
  color: var(--mute);
  font-size: 0.88rem;
}

.fb-card {
  margin-top: 28px;
  background: var(--card);
  backdrop-filter: blur(14px);
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 4px);
  padding: 24px;
  display: grid;
  gap: 16px;
  max-width: 560px;
  box-shadow: 0 18px 50px rgba(40, 70, 110, 0.08);
}
.fb-card label { display: grid; gap: 8px; }
.fb-card span { font-size: 0.9rem; color: var(--mute); }
.fb-card input,
.fb-card textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 12px 14px;
  font: inherit;
  background: rgba(255,255,255,0.85);
  color: var(--ink);
  resize: vertical;
}
.fb-card input:focus,
.fb-card textarea:focus {
  outline: 2px solid rgba(61, 126, 166, 0.35);
  border-color: transparent;
}
.fb-msg {
  margin: 0;
  font-size: 0.95rem;
}
.fb-msg.ok { color: #1f7a4d; }
.fb-msg.err { color: #b42318; }

.feedback { padding-bottom: 96px; }

@media (max-width: 640px) {
  .brand-name { font-size: 1.15rem; }
  .hero { padding-top: 72px; }
}