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

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  background: #f0f2f5;
  color: #1f2329;
  min-height: 100vh;
}

.container {
  max-width: 680px;
  margin: 0 auto;
  padding: 40px 20px 60px;
}

.header { text-align: center; margin-bottom: 28px; }
.header h1 { font-size: 28px; font-weight: 700; color: #1a1a2e; }
.subtitle { color: #8a94a6; font-size: 13px; margin-top: 6px; }

.mode-badge {
  display: inline-block;
  margin-top: 10px;
  font-size: 12px;
  padding: 4px 12px;
  border-radius: 999px;
}
.mode-ok { background: #e6f7ec; color: #0a7a3d; }
.mode-demo { background: #fff7e6; color: #a05a00; }

.add-form {
  display: flex;
  gap: 10px;
  background: #fff;
  padding: 14px;
  border-radius: 12px;
  box-shadow: 0 1px 4px rgba(0,0,0,.06);
}

.input {
  flex: 1;
  border: 1px solid #e0e4ea;
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 14px;
  outline: none;
  transition: border-color .15s;
}
.input:focus { border-color: #3b82f6; }

.select {
  border: 1px solid #e0e4ea;
  border-radius: 8px;
  padding: 10px 10px;
  font-size: 14px;
  background: #fff;
  outline: none;
  cursor: pointer;
}

.btn {
  border: none;
  border-radius: 8px;
  padding: 9px 16px;
  font-size: 14px;
  cursor: pointer;
  transition: opacity .15s, transform .05s;
}
.btn:active { transform: scale(.97); }
.btn:disabled { opacity: .5; cursor: not-allowed; }

.btn-add { background: #3b82f6; color: #fff; font-weight: 600; }
.btn-add:hover { background: #2563eb; }

.toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin: 20px 0 12px;
  flex-wrap: wrap;
  gap: 8px;
}

.filters { display: flex; gap: 6px; }

.filter-btn {
  border: 1px solid #e0e4ea;
  background: #fff;
  color: #4b5563;
  border-radius: 999px;
  padding: 5px 14px;
  font-size: 13px;
  cursor: pointer;
  transition: all .15s;
}
.filter-btn:hover { border-color: #3b82f6; color: #3b82f6; }
.filter-btn.active { background: #3b82f6; border-color: #3b82f6; color: #fff; }

.stat { font-size: 13px; color: #8a94a6; }

.error {
  background: #fdecec;
  color: #c0392b;
  border: 1px solid #f5c6c6;
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 13px;
  margin-bottom: 12px;
}

.empty {
  text-align: center;
  color: #9aa5b5;
  padding: 48px 0;
  background: #fff;
  border-radius: 12px;
  font-size: 14px;
}

.task-list { list-style: none; display: flex; flex-direction: column; gap: 10px; }

.task {
  display: flex;
  align-items: center;
  gap: 12px;
  background: #fff;
  border-radius: 12px;
  padding: 14px 16px;
  box-shadow: 0 1px 3px rgba(0,0,0,.05);
  transition: opacity .2s;
}

.tag {
  flex-shrink: 0;
  font-size: 12px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 6px;
}
.p-high { background: #fdeaea; color: #d93025; }
.p-mid  { background: #fff3e0; color: #e07c00; }
.p-low  { background: #e6f4ea; color: #188038; }

.title { flex: 1; font-size: 15px; word-break: break-all; }

.task.done { opacity: .55; }
.task.done .title { text-decoration: line-through; color: #8a94a6; }

.actions { display: flex; gap: 8px; flex-shrink: 0; }

.btn-toggle { background: #eef4ff; color: #2563eb; font-size: 13px; padding: 6px 12px; }
.btn-toggle:hover { background: #dbeafe; }
.btn-delete { background: #f3f4f6; color: #6b7280; font-size: 13px; padding: 6px 12px; }
.btn-delete:hover { background: #fdeaea; color: #d93025; }

.footer {
  margin-top: 32px;
  text-align: center;
  font-size: 12px;
  color: #b3bccb;
}