:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --bg: #f7f8fa;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #e5e7eb;
  --radius: 16px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
}

body {
  font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.site-header {
  text-align: center;
  padding: 28px 16px 8px;
  border-bottom: 1px solid var(--border);
  background: var(--card);
}

.site-header h1 {
  margin: 0;
  font-size: 22px;
  font-weight: 700;
}

.subtitle {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.layout {
  max-width: 1040px;
  margin: 0 auto;
  padding: 24px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: start;
}

.panel,
.preview-wrap {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}

.panel-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--muted);
  margin: 18px 0 12px;
  padding-left: 10px;
  border-left: 3px solid var(--primary);
}

.panel-title:first-child { margin-top: 0; }

.field { margin-bottom: 14px; }

.field label {
  display: block;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 6px;
}

.field .req { color: #ef4444; }

.field .val { color: var(--text); font-weight: 600; }

input[type="text"],
select {
  width: 100%;
  padding: 10px 12px;
  font-size: 14px;
  color: var(--text);
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  outline: none;
  transition: border-color 0.15s, box-shadow 0.15s;
}

input[type="text"]:focus,
select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

input[type="range"] { width: 100%; accent-color: var(--primary); }

.colors {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.color-field label { margin-bottom: 6px; }

input[type="color"] {
  width: 100%;
  height: 38px;
  padding: 2px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: #fff;
  cursor: pointer;
}

.switch-field {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  color: var(--muted);
}

.switch { position: relative; display: inline-block; width: 46px; height: 26px; }
.switch input { opacity: 0; width: 0; height: 0; }
.slider {
  position: absolute;
  inset: 0;
  background: #cbd5e1;
  border-radius: 999px;
  transition: background 0.2s;
  cursor: pointer;
}
.slider::before {
  content: "";
  position: absolute;
  height: 20px; width: 20px;
  left: 3px; top: 3px;
  background: #fff;
  border-radius: 50%;
  transition: transform 0.2s;
}
.switch input:checked + .slider { background: var(--primary); }
.switch input:checked + .slider::before { transform: translateX(20px); }

.templates { display: flex; flex-wrap: wrap; gap: 8px; }

.tpl-btn {
  padding: 8px 14px;
  font-size: 13px;
  color: var(--text);
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.15s;
}
.tpl-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.preview-wrap { text-align: center; }

.canvas-box {
  display: flex;
  justify-content: center;
}

#preview {
  width: 100%;
  max-width: 380px;
  height: auto;
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
  background: #fff;
}

.hint { color: var(--muted); font-size: 12px; margin: 12px 0 0; }

.actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-top: 14px;
}

.btn {
  padding: 10px 20px;
  font-size: 14px;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  transition: background 0.15s, transform 0.05s;
}
.btn:active { transform: translateY(1px); }

.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }

.btn-secondary {
  background: #fff;
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover { background: #f0f4ff; border-color: var(--primary); }

.status {
  min-height: 18px;
  margin: 10px 0 0;
  color: var(--primary);
  font-size: 13px;
}

.site-footer {
  text-align: center;
  color: var(--muted);
  font-size: 12px;
  padding: 20px 16px 32px;
}

@media (max-width: 820px) {
  .layout { grid-template-columns: 1fr; }
}