:root {
  --primary: #4a7de0;
  --primary-dark: #3a63b8;
  --bg: #f5f7fb;
  --card: #ffffff;
  --text: #2c3e50;
  --muted: #8a97a8;
  --border: #e3e9f2;
  --success: #2e9e5b;
  --danger: #d9534f;
  --radius: 12px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  background: var(--bg); color: var(--text); line-height: 1.6;
}
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

.site-header {
  background: var(--card); border-bottom: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 24px; flex-wrap: wrap; gap: 8px;
}
.site-header .logo { font-size: 1.3rem; font-weight: 700; color: var(--primary); }
.site-header nav { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.site-header .who { color: var(--muted); font-size: .9rem; }

.container { max-width: 1080px; margin: 24px auto; padding: 0 16px; }
.site-footer { text-align: center; color: var(--muted); padding: 32px 0 24px; font-size: .85rem; }

h2 { margin: 16px 0; }
h2 small { font-weight: 400; }
.muted { color: var(--muted); font-size: .9rem; }
.small { font-size: .85rem; }

/* 按钮 */
.btn {
  display: inline-block; background: var(--primary); color: #fff; border: none;
  padding: 9px 20px; border-radius: 8px; cursor: pointer; font-size: 1rem;
  transition: background .15s;
}
.btn:hover { background: var(--primary-dark); text-decoration: none; }
.btn:disabled { background: #b8c4d6; cursor: not-allowed; }
.btn-sm { padding: 5px 14px; font-size: .9rem; }
.btn-block { width: 100%; }
.btn-done { background: var(--success); }
.btn-danger { background: var(--danger); }
.btn-vote { font-size: 1.1rem; padding: 12px 32px; }

/* 作品网格 */
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 16px; }
.card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; display: block; color: var(--text); transition: box-shadow .15s, transform .15s;
}
.card:hover { text-decoration: none; box-shadow: 0 6px 18px rgba(74,125,224,.15); transform: translateY(-2px); }
.thumb { width: 100%; height: 160px; object-fit: cover; display: block; background: #eef2f8; }
.thumb-pdf { display: flex; align-items: center; justify-content: center; height: 160px; font-size: 2rem; color: var(--muted); }
.card-body { padding: 12px 14px; }
.card-body h3 { font-size: 1rem; margin-bottom: 4px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.votes { color: var(--primary); font-weight: 600; }
.votes.big { font-size: 1.3rem; margin-right: 16px; }

/* 详情页 */
.work-detail .full { max-width: 100%; border-radius: var(--radius); border: 1px solid var(--border); margin: 12px 0; }
.work-detail .desc { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px; margin: 12px 0; }
.vote-box { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; margin: 16px 0; display: flex; align-items: center; flex-wrap: wrap; gap: 8px; }
.vote-msg { color: var(--success); }

/* 表格 */
.table { width: 100%; border-collapse: collapse; background: var(--card); border-radius: var(--radius); overflow: hidden; margin: 12px 0; }
.table th, .table td { padding: 10px 14px; border-bottom: 1px solid var(--border); text-align: left; }
.table th { background: #eef3fb; font-size: .9rem; }
.rank-table .top3 { background: #fffbe8; }

/* 表单 */
.form { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; max-width: 560px; }
.form label { display: block; margin-bottom: 14px; font-weight: 600; }
.form input[type=text], .form textarea, .form input[type=file], .form input[type=password], .form input[type=number], .form select {
  display: block; width: 100%; margin-top: 6px; padding: 9px 12px;
  border: 1px solid var(--border); border-radius: 8px; font-size: 1rem; font-family: inherit;
}
.form input:focus, .form textarea:focus { outline: 2px solid var(--primary); border-color: transparent; }

/* 提示条 */
.alert { padding: 10px 16px; border-radius: 8px; margin: 12px 0; }
.alert-error { background: #fdecea; color: var(--danger); }
.alert-success { background: #e8f6ee; color: var(--success); }
.alert-info { background: #e8f0fd; color: var(--primary-dark); }
.banner { background: #fff8e6; border: 1px solid #f2e3b3; border-radius: var(--radius); padding: 14px; margin: 16px 0; }
.empty { text-align: center; color: var(--muted); background: var(--card); border: 1px dashed var(--border); border-radius: var(--radius); padding: 40px 20px; margin: 16px 0; }

/* 登录页 */
.login-body { display: flex; align-items: center; justify-content: center; min-height: 100vh; background: linear-gradient(135deg, #dfe9fb 0%, #f5f7fb 100%); }
.login-card { background: var(--card); border-radius: 16px; box-shadow: 0 10px 40px rgba(74,125,224,.15); padding: 36px 32px; width: 360px; max-width: 92vw; }
.login-card h1 { font-size: 1.4rem; margin-bottom: 6px; text-align: center; }
.login-card .tip { color: var(--muted); text-align: center; margin-bottom: 18px; font-size: .9rem; }
.login-card label { display: block; margin-bottom: 14px; font-weight: 600; }
.login-card input { display: block; width: 100%; margin-top: 6px; padding: 10px 12px; border: 1px solid var(--border); border-radius: 8px; font-size: 1rem; }
.login-card .small { margin-top: 14px; color: var(--muted); }

/* 后台 */
.admin-nav { background: var(--card); border-bottom: 1px solid var(--border); padding: 10px 24px; display: flex; gap: 16px; flex-wrap: wrap; align-items: center; }
.admin-nav a { color: var(--text); }
.admin-nav a.active { color: var(--primary); font-weight: 700; }
.stat-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 14px; margin: 16px 0; }
.stat-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; text-align: center; }
.stat-card .num { font-size: 1.8rem; font-weight: 700; color: var(--primary); }
.pager { margin: 16px 0; display: flex; gap: 6px; }
.pager a, .pager strong { padding: 5px 12px; border: 1px solid var(--border); border-radius: 6px; background: var(--card); }

@media (max-width: 600px) {
  .grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .site-header { padding: 10px 14px; }
}