:root {
  --primary: #0066FF;
  --primary-bg: #EFF6FF;
  --primary-hover: #0052CC;
  --success: #10B981;
  --success-bg: #ECFDF5;
  --warn: #F59E0B;
  --warn-bg: #FFFBEB;
  --danger: #EF4444;
  --danger-bg: #FEF2F2;
  --bg: #F8FAFC;
  --card: #FFFFFF;
  --text: #0F172A;
  --text-sec: #64748B;
  --text-muted: #94A3B8;
  --border: #E2E8F0;
  --border-strong: #CBD5E1;
  --radius: 16px;
  --radius-sm: 10px;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

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

body {
  font-family: -apple-system, "PingFang SC", "Helvetica Neue", sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.5;
  display: flex;
  flex-direction: column;
}

a {
  text-decoration: none;
  color: inherit;
}

main {
  flex: 1;
}

/* 顶部品牌条 */
.topbar {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.topbar-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 700;
}

.brand-logo {
  width: 30px;
  height: 30px;
  border-radius: 8px;
  background: linear-gradient(135deg, #0066FF, #3B82F6);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
}

.back-link {
  font-size: 13px;
  color: var(--text-sec);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.back-link:hover {
  color: var(--primary);
}

/* 工具页主容器 */
.tool-page {
  max-width: 1100px;
  margin: 0 auto;
  padding: 32px 24px 40px;
  width: 100%;
}

.tool-page h1 {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.tool-page .lead {
  color: var(--text-sec);
  font-size: 14px;
  margin-top: 6px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  margin-top: 20px;
}

.card-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-sec);
  margin-bottom: 6px;
  display: block;
}

/* 表单元素 */
textarea,
input[type="text"],
input[type="number"],
select {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  font-size: 13px;
  font-family: var(--mono);
  color: var(--text);
  background: #fff;
  outline: none;
  transition: border-color .15s, box-shadow .15s;
}

input[type="text"],
input[type="number"],
select {
  font-family: inherit;
}

textarea {
  resize: vertical;
  min-height: 200px;
  line-height: 1.55;
}

textarea:focus,
input:focus,
select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(0, 102, 255, .12);
}

textarea[readonly] {
  background: #F8FAFC;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all .15s;
  white-space: nowrap;
  font-family: inherit;
}

.btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

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

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

.btn-sm {
  padding: 5px 10px;
  font-size: 12px;
}

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

/* 状态条 */
.status {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 500;
}

.status-ok {
  background: var(--success-bg);
  color: var(--success);
}

.status-err {
  background: var(--danger-bg);
  color: var(--danger);
}

.status-warn {
  background: var(--warn-bg);
  color: var(--warn);
}

.status-info {
  background: var(--primary-bg);
  color: var(--primary);
}

/* 双栏 */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 800px) {
  .split {
    grid-template-columns: 1fr;
  }
}

/* 提示信息 */
.tip {
  background: var(--warn-bg);
  border: 1px solid #FDE68A;
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  font-size: 12px;
  color: #92400E;
  margin-top: 12px;
}

/* 代码输出 */
pre.output {
  background: #0F172A;
  color: #E2E8F0;
  padding: 14px;
  border-radius: var(--radius-sm);
  font-family: var(--mono);
  font-size: 12.5px;
  line-height: 1.6;
  overflow: auto;
  max-height: 420px;
  white-space: pre-wrap;
  word-break: break-all;
}

/* Footer */
.footer {
  text-align: center;
  font-size: 12px;
  color: var(--text-muted);
  padding: 24px 24px 32px;
  border-top: 1px solid var(--border);
  background: var(--card);
}

@media (max-width: 600px) {
  .tool-page {
    padding: 20px 16px 28px;
  }
  .tool-page h1 {
    font-size: 20px;
  }
}

/* 顶部友链导航 */
.topbar-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.topbar-nav .back-link {
  margin-left: 8px;
  padding-left: 12px;
  border-left: 1px solid var(--border);
}

.topbar-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-sec);
  transition: background .15s, color .15s;
}

.topbar-link:hover {
  background: var(--primary-bg);
  color: var(--primary);
}

.topbar-link svg {
  flex-shrink: 0;
}

@media (max-width: 600px) {
  .topbar-link span {
    display: none;
  }
  .topbar-link {
    padding: 7px 10px;
  }
}

/* 页脚友链 */
.footer-links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 8px;
}

.footer-links a {
  color: var(--text-sec);
  transition: color .15s;
}

.footer-links a:hover {
  color: var(--primary);
}

/* 微信浮动球 + 弹窗 */
.wechat-fab {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, #07C160, #10B981);
  color: #fff;
  border: none;
  cursor: pointer;
  box-shadow: 0 6px 20px rgba(7, 193, 96, .35);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform .2s, box-shadow .2s;
  z-index: 50;
}

.wechat-fab:hover {
  transform: translateY(-3px) scale(1.05);
  box-shadow: 0 10px 28px rgba(7, 193, 96, .45);
}

.wechat-popup {
  position: fixed;
  right: 24px;
  bottom: 96px;
  width: 220px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: 0 12px 32px rgba(15, 23, 42, .12);
  z-index: 49;
  text-align: center;
  transform: translateY(8px) scale(.96);
  opacity: 0;
  pointer-events: none;
  transition: transform .2s, opacity .2s;
}

.wechat-popup.show {
  transform: translateY(0) scale(1);
  opacity: 1;
  pointer-events: auto;
}

.wechat-popup::after {
  content: '';
  position: absolute;
  right: 22px;
  bottom: -7px;
  width: 14px;
  height: 14px;
  background: var(--card);
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  transform: rotate(45deg);
}

.wechat-popup img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
  display: block;
}

.wechat-popup-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 10px;
}

.wechat-popup-tip {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 8px;
}

.wechat-popup-fallback {
  display: none;
  padding: 32px 8px;
  color: var(--text-muted);
  font-size: 12px;
  border: 1px dashed var(--border);
  border-radius: 10px;
}