/* ========================================
   公共样式 - 全站通用
   ======================================== */

:root {
  /* 品牌色系 */
  --color-primary: #1f66b3;
  --color-primary-dark: #175aa1;

  /* 基础色系 */
  --color-white: #fff;
  --color-text: #0f172a;
  --color-muted: #64748b;
  --color-dark: #0b1220;

  /* 背景与卡片 */
  --color-bg: #ffffff;
  --color-surface: #ffffff;
  --color-light-gray: #f8f9fa;

  /* 边框 */
  --color-border: #e5e7eb;

  /* 透明色系 */
  --color-white-65: rgba(255, 255, 255, .65);
  --color-white-25: rgba(255, 255, 255, .25);
  --color-white-40: rgba(255, 255, 255, .4);
  --color-dark-28: rgba(2, 6, 23, .28);
  --color-dark-35: rgba(2, 6, 23, .35);
  --color-dark-10: rgba(2, 6, 23, .10);
  --color-black-45: rgba(0, 0, 0, .45);
  --color-black-12: rgba(0, 0, 0, .12);

  /* 效果系 */
  --effect-shadow-lg: 0 10px 30px rgba(2, 6, 23, .12);
  --effect-shadow-md: 0 8px 24px rgba(0, 0, 0, .12);
  --effect-shadow-sm: 0 2px 8px rgba(0, 0, 0, .25);
  --effect-text-shadow: 0 6px 16px rgba(0, 0, 0, .35);
  --effect-blur-md: blur(8px);

  /* 布局尺寸 */
  --layout-max: 85%;
  --layout-header-h: 0px;
}

* {
  box-sizing: border-box
}

body {
  margin: 0;
  padding-top: var(--layout-header-h);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, "PingFang SC", "Noto Sans SC", Arial;
  color: var(--color-text);
  background: var(--color-bg);
}

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

.container {
  max-width: var(--layout-max);
  margin: 0 auto;
  padding: 0 16px
}

/* ========================================
   头部导航 Header
   ======================================== */
.header {
  background: transparent;
  color: var(--color-white);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  border-bottom: 1px solid var(--color-white-65);
}

.header.is-solid {
  background: var(--color-primary);
  color: var(--color-white);
  border-bottom: 1px solid var(--color-white-25);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px
}

.logo img {
  height: 48px;
  display: block;
}

.nav {
  display: flex;
  gap: 30px;
  font-size: 18px
}

.nav a {
  opacity: .95
}

.nav a:hover {
  opacity: 1;
  text-decoration: underline
}

/* ========================================
   页脚 Footer
   ======================================== */
.footer {
  background: var(--color-primary-dark);
  color: var(--color-white);
  padding-top: 26px;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 20px;
  padding-bottom: 18px;
}

.footer-brand {
  font-weight: 900;
  font-size: 16px;
  margin-bottom: 10px
}

.footer-item {
  opacity: .92;
  margin: 8px 0;
  font-size: 13px
}

.footer-title {
  font-weight: 900;
  margin-bottom: 10px
}

.footer-link {
  display: block;
  opacity: .92;
  font-size: 13px;
  margin: 8px 0;
}

.footer-link:hover {
  text-decoration: underline;
  opacity: 1
}

.footer-bottom {
  border-top: 1px solid var(--color-white-25);
  padding: 12px 0;
  font-size: 12px;
  opacity: .95;
}

.footer-bottom-inner {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
}

.float {
  position: fixed;
  right: 16px;
  bottom: 16px;
  top: auto;
  transform: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  z-index: 90;
}

.to-top {
  width: 44px;
  height: 44px;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  background: var(--color-white);
  box-shadow: var(--effect-shadow-lg);
  font-size: 18px;
}