/* ============ 全局基础 ============ */
:root {
  --bg: #0d1117;
  --bg-card: #161b22;
  --border: #30363d;
  --text: #e6edf3;
  --text-dim: #8b949e;
  --accent: #58a6ff;
  --accent-2: #7ee787;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: system-ui, -apple-system, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}

/* ============ 导航 ============ */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(13, 17, 23, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 860px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo { font-weight: 700; color: var(--text); text-decoration: none; }

.nav nav a {
  color: var(--text-dim);
  text-decoration: none;
  margin-left: 18px;
  font-size: 15px;
}
.nav nav a:hover { color: var(--accent); }

/* ============ Hero ============ */
.hero {
  max-width: 860px;
  margin: 0 auto;
  padding: 90px 20px 60px;
  text-align: center;
}

.hero h1 { font-size: clamp(2rem, 6vw, 3.2rem); }

.accent {
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.subtitle { margin-top: 12px; font-size: 1.15rem; color: var(--text-dim); }

.tiny { font-size: 0.85rem; color: var(--text-dim); }

.cta {
  display: inline-block;
  margin-top: 28px;
  padding: 12px 28px;
  border-radius: 999px;
  background: var(--accent);
  color: #0d1117;
  font-weight: 600;
  text-decoration: none;
  transition: transform 0.15s ease;
}
.cta:hover { transform: translateY(-2px); }

/* ============ 卡片区 ============ */
.card {
  max-width: 860px;
  margin: 0 auto 28px;
  padding: 28px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
}

.card h2 { margin-bottom: 16px; font-size: 1.4rem; }
.card p { margin-bottom: 10px; }

.skills {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.skills li {
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 0.9rem;
  color: var(--accent-2);
  background: rgba(126, 231, 135, 0.06);
}

/* ============ 留言板表单 ============ */
#guestbook-form .row { margin-bottom: 12px; }

#guestbook-form input,
#guestbook-form textarea {
  width: 100%;
  padding: 12px 14px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font: inherit;
  resize: vertical;
}
#guestbook-form input:focus,
#guestbook-form textarea:focus {
  outline: none;
  border-color: var(--accent);
}

#submit-btn {
  padding: 10px 24px;
  border: none;
  border-radius: 8px;
  background: var(--accent);
  color: #0d1117;
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
}
#submit-btn:disabled { opacity: 0.5; cursor: not-allowed; }

.status { margin-left: 12px; font-size: 0.9rem; }
.status.ok { color: var(--accent-2); }
.status.err { color: #ff7b72; }

/* ============ 留言列表 ============ */
.messages { margin-top: 24px; }

.msg {
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: 10px;
  margin-bottom: 12px;
  background: rgba(88, 166, 255, 0.04);
}

.msg-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 6px;
}
.msg-name { font-weight: 600; color: var(--accent); }
.msg-time { font-size: 0.8rem; color: var(--text-dim); }
.msg-body { word-break: break-word; white-space: pre-wrap; }

/* ============ 页脚 ============ */
footer {
  text-align: center;
  padding: 40px 20px;
  color: var(--text-dim);
  font-size: 0.85rem;
}