/* ====== 自适应设计：手机优先 ====== */
* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary: #1e6fff;
  --primary-dark: #0b54d3;
  --text: #1f2937;
  --text-soft: #4b5563;
  --bg: #f7f9fc;
  --card: #ffffff;
  --border: #e5e7eb;
  --accent: #0aa37f;
  --shadow: 0 4px 16px rgba(15, 23, 42, 0.06);
}

@media (prefers-color-scheme: dark) {
  :root {
    --text: #e5e7eb;
    --text-soft: #9ca3af;
    --bg: #0f172a;
    --card: #1e293b;
    --border: #334155;
    --shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
  }
}

html { -webkit-text-size-adjust: 100%; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial,
    sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
a:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; }

.container {
  width: 100%;
  max-width: 880px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ====== 顶部 Hero ====== */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: #fff;
  padding: 56px 0 48px;
  text-align: center;
}

.hero h1 {
  font-size: clamp(1.5rem, 4.5vw, 2.25rem);
  font-weight: 700;
  letter-spacing: 1px;
  margin-bottom: 12px;
}

.hero .subtitle {
  font-size: clamp(0.95rem, 2.4vw, 1.05rem);
  opacity: 0.92;
}

/* ====== 主体区 ====== */
.main { padding: 32px 0 56px; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px 20px;
  margin-bottom: 20px;
  box-shadow: var(--shadow);
}

.card h2 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 14px;
  color: var(--primary-dark);
  display: flex;
  align-items: center;
  gap: 8px;
}

.card h2::before {
  content: "";
  display: inline-block;
  width: 4px;
  height: 18px;
  background: var(--primary);
  border-radius: 2px;
}

.card p { color: var(--text-soft); margin-bottom: 10px; }
.card p:last-child { margin-bottom: 0; }

/* ====== 二维码区 ====== */
.qr-section {
  text-align: center;
  padding: 32px 20px;
}

.qr-wrap {
  display: inline-block;
  background: #fff;
  padding: 16px;
  border-radius: 12px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.qr-wrap img {
  display: block;
  width: 200px;
  height: 200px;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
}

.qr-tip {
  margin-top: 14px;
  font-size: 0.95rem;
  color: var(--text-soft);
}

.qr-id {
  display: inline-block;
  margin-top: 6px;
  padding: 4px 12px;
  background: rgba(30, 111, 255, 0.08);
  color: var(--primary);
  font-weight: 600;
  border-radius: 6px;
  font-size: 0.9rem;
  letter-spacing: 0.5px;
}

/* ====== 链接按钮组 ====== */
.links {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.link-item {
  display: block;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--card);
  color: var(--text);
  transition: border-color 0.2s, transform 0.1s;
}

.link-item:hover {
  border-color: var(--primary);
  text-decoration: none;
  transform: translateY(-1px);
}

.link-item .label {
  font-weight: 600;
  color: var(--primary-dark);
  display: block;
  margin-bottom: 4px;
}

.link-item .desc {
  font-size: 0.88rem;
  color: var(--text-soft);
}

.link-item .arrow {
  float: right;
  color: var(--primary);
  font-weight: 700;
}

/* ====== 投稿信息 ====== */
.contact-line {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 8px 0;
}

.contact-line .key {
  color: var(--text-soft);
  font-size: 0.92rem;
}

.email {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  background: rgba(30, 111, 255, 0.08);
  padding: 2px 8px;
  border-radius: 4px;
  color: var(--primary-dark);
  font-size: 0.95rem;
}

/* ====== 页脚 ====== */
.footer {
  text-align: center;
  padding: 24px 20px;
  color: var(--text-soft);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
}

/* ====== 响应式：>=640px 双栏 ====== */
@media (min-width: 640px) {
  .hero { padding: 72px 0 64px; }
  .main { padding: 40px 0 64px; }
  .card { padding: 28px 28px; }
  .links {
    grid-template-columns: 1fr 1fr;
  }
}

@media (min-width: 900px) {
  body { font-size: 17px; }
  .qr-wrap img { width: 220px; height: 220px; }
}