:root{
  --bg:#f5f7fb;              /* 主背景：浅灰偏冷 */
  --panel:#ffffff;           /* 顶部导航、hero */
  --card:#ffffff;            /* 卡片 */
  --text:#1f2937;            /* 主文字（深灰） */
  --muted:#6b7280;           /* 次级文字 */
  --accent:#2563eb;          /* 工程感蓝 */
  --border:rgba(0,0,0,.08);  /* 浅边框 */
  --shadow: 0 8px 24px rgba(0,0,0,.08);
}

*{ box-sizing:border-box; }
html,body{ margin:0; padding:0; }
body{
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
  background:
    radial-gradient(1000px 500px at 15% 0%, rgba(37,99,235,.06), transparent 55%),
    radial-gradient(800px 400px at 85% 15%, rgba(16,185,129,.05), transparent 60%),
    var(--bg);
  color:var(--text);
  line-height:1.65;
}

a{ color:var(--accent); text-decoration:none; }
a:hover{ text-decoration:underline; }

.container{ max-width: 980px; margin: 0 auto; padding: 28px 18px 50px; }

.nav{
  display:flex; gap:14px; align-items:center; justify-content:space-between;
  padding: 14px 16px; border:1px solid var(--border); border-radius:14px;
  background: rgba(255,255,255,.85); backdrop-filter: blur(6px);
  box-shadow: var(--shadow);
}

.nav .left{ display:flex; gap:12px; align-items:center; }
.badge{
  font-size: 12px;
  padding: 3px 10px;
  border:1px solid var(--border);
  border-radius:999px;
  color:var(--muted);
  background: rgba(0,0,0,.02);
}
.brand{
  font-weight:700;
  letter-spacing:.2px;
}
.links{ display:flex; gap:12px; flex-wrap:wrap; }
.links a{
  padding: 6px 10px;
  border-radius: 10px;
  border:1px solid transparent;
  color:var(--text);
  opacity:.9;
}
.links a.active{
  border-color: var(--border);
  background: rgba(0,0,0,.03);
  opacity:1;
}

.hero{
  margin-top: 18px;
  padding: 26px 22px;
  border:1px solid var(--border);
  border-radius: 18px;
  background: linear-gradient(
    180deg,
    rgba(255,255,255,.95),
    rgba(245,247,251,.95)
  );
  box-shadow: var(--shadow);
}

h1{ margin: 0 0 8px; font-size: 30px; }
h2{ margin: 0 0 10px; font-size: 18px; color: #1d4ed8; }
p{ margin: 10px 0; color: var(--text); }
.muted{ color: var(--muted); }

.grid{
  display:grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 14px;
  margin-top: 14px;
}

.card{
  grid-column: span 12;
  border:1px solid var(--border);
  border-radius: 16px;
  background: rgba(255,255,255,.9);
  box-shadow: var(--shadow);
  padding: 18px 18px 16px;
}
@media (min-width: 820px){
  .card.half{ grid-column: span 6; }
  .card.third{ grid-column: span 4; }
}

.kv{ display:flex; gap:12px; flex-wrap:wrap; margin-top: 10px; }
.kv .item{
  border:1px solid var(--border);
  background: rgba(0,0,0,.02);
  border-radius: 14px;
  padding: 10px 12px;
  min-width: 210px;
}
.kv .item b{ display:block; font-size: 12px; color: var(--muted); font-weight:600; }
.kv .item span{ display:block; margin-top: 3px; }

.tags{ display:flex; gap:8px; flex-wrap:wrap; margin-top:10px; }
.tag{
  font-size: 12px;
  color: var(--muted);
  border:1px solid var(--border);
  background: rgba(0,0,0,.02);
  padding: 2px 10px;
  border-radius: 999px;
}

.list{
  display:flex;
  flex-direction:column;
  gap: 10px;
  margin-top: 10px;
}

.row{
  border:1px solid var(--border);
  background: rgba(0,0,0,.02);
  border-radius: 14px;
  padding: 12px 14px;
}
.row .top{
  display:flex;
  gap:10px;
  align-items:baseline;
  justify-content:space-between;
  flex-wrap:wrap;
}
.row .title{ font-weight:650; }
.row .meta{ color: var(--muted); font-size: 12px; }

.footer{
  margin-top: 22px;
  text-align:center;
  color: var(--muted);
  font-size: 12px;
  opacity: .9;
}

code{
  background: rgba(37,99,235,.06);
  border:1px solid rgba(37,99,235,.18);
  padding: 2px 6px;
  border-radius: 8px;
  color: #0b2a6f;
}

/* About 头像布局（工程风：圆角矩形） */
.profile-wrap{
  display: flex;
  gap: 18px;
  align-items: center;
  flex-wrap: wrap;
}

.profile-photo{
  width: 140px;
  height: 140px;
  border-radius: 18px;
  object-fit: cover;
  border: 1px solid rgba(0,0,0,.12);
  background: #f3f4f6;
  box-shadow: 0 6px 18px rgba(0,0,0,.12);
}

.profile-text{
  flex: 1;
  min-width: 240px;
}