/* =========================================================
   硕博帮 静态站点样式表
   设计原则：移动端优先、语义化、无障碍、纯静态无依赖
   ========================================================= */
:root {
  --primary: #2b6fff;
  --primary-dark: #143a85;
  --primary-soft: #eef4ff;
  --accent: #f59e0b;
  --accent-dark: #d97706;
  --bg: #ffffff;
  --bg-soft: #f5f8ff;
  --text: #1f2937;
  --muted: #5b6472;
  --border: #e5e9f2;
  --shadow: 0 10px 30px rgba(20, 58, 133, 0.08);
  --radius: 14px;
  --maxw: 1140px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", system-ui, -apple-system, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

img, svg { max-width: 100%; display: block; }

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

h1, h2, h3 { line-height: 1.25; margin: 0 0 .5em; font-weight: 800; }

p { margin: 0 0 1em; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
  white-space: nowrap;
}
.btn:focus-visible { outline: 3px solid rgba(43,111,255,.4); outline-offset: 2px; }
.btn-primary { background: var(--primary); color: #fff; box-shadow: 0 8px 20px rgba(43,111,255,.25); }
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-1px); }
.btn-ghost { background: #fff; color: var(--primary); border-color: var(--primary); }
.btn-ghost:hover { background: var(--primary-soft); }
.btn-lg { padding: 14px 30px; font-size: 16px; }
.btn-block { width: 100%; }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255,255,255,.9);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; }
.brand-mark {
  width: 34px; height: 34px;
  display: grid; place-items: center;
  background: var(--primary); color: #fff;
  border-radius: 9px; font-size: 18px;
}
.brand-name { font-size: 20px; color: var(--primary-dark); letter-spacing: .5px; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 22px;
  font-size: 15px;
}
.nav-links a { color: var(--text); font-weight: 500; }
.nav-links a:hover { color: var(--primary); }
.nav-cta { color: #fff !important; padding: 8px 18px; }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none; border: 0; cursor: pointer; padding: 8px;
}
.nav-toggle span { width: 24px; height: 2px; background: var(--text); border-radius: 2px; transition: .2s; }

/* ---------- 通用区块 ---------- */
.section { padding: 64px 0; }
.section-soft { background: var(--bg-soft); }

/* ---------- 板块背景图（AI 生成，已裁掉水印） ---------- */
/* 蒙层保留 18%~20% 透出，既饱满生动又保证卡片与文字清晰可读 */
#services {
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.82), rgba(255, 255, 255, 0.82)),
    url("../images/services-bg.png");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}
#why {
  background-image:
    linear-gradient(rgba(245, 248, 255, 0.80), rgba(245, 248, 255, 0.80)),
    url("../images/why-bg.png");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}
/* 桌面端视差，移动端保持滚动以避免性能与错位问题 */
@media (min-width: 768px) {
  #services, #why { background-attachment: fixed; }
}
.section-head { text-align: center; max-width: 720px; margin: 0 auto 40px; }
.section-eyebrow {
  display: inline-block;
  color: var(--primary);
  font-weight: 700;
  letter-spacing: 2px;
  font-size: 13px;
  margin: 0 0 10px;
}
.section-head h2 { font-size: clamp(24px, 4vw, 34px); color: var(--primary-dark); }
.section-desc { color: var(--muted); }

/* ---------- Hero ---------- */
.hero {
  background: radial-gradient(1200px 500px at 80% -10%, rgba(43,111,255,.12), transparent 60%),
              linear-gradient(180deg, #f7faff 0%, #ffffff 100%);
  padding: 56px 0 72px;
  overflow: hidden;
}
.hero-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  align-items: center;
}
.hero-eyebrow { color: var(--primary); font-weight: 700; letter-spacing: 1px; margin-bottom: 14px; }
.hero-text h1 { font-size: clamp(30px, 6vw, 50px); color: var(--primary-dark); }
.hero-sub { color: var(--muted); font-size: 17px; max-width: 540px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin: 26px 0 30px; }
.hero-stats { list-style: none; display: flex; flex-wrap: wrap; gap: 28px; padding: 0; margin: 0; }
.hero-stats li { display: flex; flex-direction: column; }
.hero-stats strong { font-size: 28px; color: var(--primary); }
.hero-stats span { font-size: 13px; color: var(--muted); }
.hero-visual { display: none; }

/* ---------- 业务卡片 ---------- */
.cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}
.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  box-shadow: var(--shadow);
  transition: transform .18s ease, box-shadow .18s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: 0 18px 40px rgba(20,58,133,.12); }
.card-icon {
  width: 52px; height: 52px;
  display: grid; place-items: center;
  background: var(--primary-soft); color: var(--primary);
  border-radius: 12px; font-size: 24px; font-weight: 800;
  margin-bottom: 16px;
}
.card h3 { font-size: 19px; color: var(--primary-dark); }
.card p { color: var(--muted); margin: 0; font-size: 15px; }

/* ---------- 优势 ---------- */
.features {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}
.feature {
  background: #fff;
  border-radius: var(--radius);
  padding: 24px;
  border: 1px solid var(--border);
}
.feature h3 { font-size: 18px; color: var(--primary-dark); }
.feature p { color: var(--muted); margin: 0; font-size: 15px; }

/* ---------- 资讯 ---------- */
.news-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}
.news-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
}
.news-tag {
  align-self: flex-start;
  font-size: 12px;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 12px;
}
.tag-policy { background: #fde7e7; color: #c0392b; }
.tag-info { background: var(--primary-soft); color: var(--primary); }
.news-card h3 { font-size: 18px; color: var(--text); }
.news-card p { color: var(--muted); font-size: 15px; flex: 1; }
.news-card time { color: #9aa3b2; font-size: 13px; margin-top: 10px; }
.news-note { text-align: center; color: var(--muted); margin-top: 28px; }

/* ---------- 关于 ---------- */
.about { display: grid; grid-template-columns: 1fr; gap: 28px; align-items: start; }
.about-text h2 { font-size: clamp(22px, 4vw, 30px); color: var(--primary-dark); }
.about-slogan { color: var(--primary); font-weight: 700; }
.about-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
  box-shadow: var(--shadow);
}
.about-card h3 { color: var(--primary-dark); }
.about-card ul { margin: 0; padding-left: 20px; color: var(--muted); }
.about-card li { margin-bottom: 10px; }

/* ---------- 联系 ---------- */
.contact { background: linear-gradient(135deg, var(--primary-dark), var(--primary)); color: #fff; }
.contact .section-eyebrow { color: #cfe0ff; }
.contact-inner { display: grid; grid-template-columns: 1fr; gap: 32px; }
.contact-info h2 { color: #fff; font-size: clamp(22px, 4vw, 30px); }
.contact-info p { color: #dbe6ff; }
.contact-list { list-style: none; padding: 0; margin: 20px 0 0; }
.contact-list li { display: flex; flex-direction: column; padding: 12px 0; border-top: 1px solid rgba(255,255,255,.18); }
.contact-list span { font-size: 13px; color: #bcd0ff; }
.contact-list strong { font-size: 17px; }

.contact-form {
  background: #fff;
  color: var(--text);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
}
.field { margin-bottom: 16px; }
.field label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 6px; }
.field input, .field select, .field textarea {
  width: 100%;
  padding: 11px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 15px;
  font-family: inherit;
  background: #fff;
  color: var(--text);
}
.field input:focus, .field select:focus, .field textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(43,111,255,.15);
}
.field textarea { resize: vertical; }
.form-hint { font-size: 14px; margin: 12px 0 0; min-height: 20px; }
.form-hint.ok { color: #15803d; }
.form-hint.err { color: #c0392b; }

/* ---------- 页脚 ---------- */
.site-footer { background: #0f244a; color: #c7d3ec; padding: 40px 0 28px; }
.footer-inner { display: flex; flex-direction: column; gap: 18px; align-items: flex-start; }
.footer-brand .brand-name { color: #fff; }
.footer-brand p { color: #9fb1d6; font-size: 14px; max-width: 360px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 18px; }
.footer-links a { color: #c7d3ec; font-size: 14px; }
.footer-links a:hover { color: #fff; }
.footer-copy { color: #7e90b8; font-size: 13px; margin: 0; }

/* =========================================================
   响应式断点
   ========================================================= */
@media (min-width: 600px) {
  .cards { grid-template-columns: repeat(2, 1fr); }
  .features { grid-template-columns: repeat(2, 1fr); }
  .news-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 768px) {
  .hero-inner { grid-template-columns: 1.1fr .9fr; }
  .hero-visual { display: block; }
  .about { grid-template-columns: 1.2fr .8fr; }
  .contact-inner { grid-template-columns: 1fr 1fr; }
  .news-grid { grid-template-columns: repeat(3, 1fr); }
  .footer-inner { flex-direction: row; flex-wrap: wrap; justify-content: space-between; align-items: center; }
}

@media (min-width: 1024px) {
  .section { padding: 88px 0; }
  .cards { grid-template-columns: repeat(3, 1fr); }
  .features { grid-template-columns: repeat(4, 1fr); }
}

/* 移动端导航：折叠菜单 */
@media (max-width: 767px) {
  .nav-toggle { display: flex; }
  .nav-links {
    position: absolute;
    top: 64px; left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: #fff;
    border-bottom: 1px solid var(--border);
    padding: 8px 20px 16px;
    box-shadow: var(--shadow);
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 0; border-bottom: 1px solid var(--border); }
  .nav-links .nav-cta { margin-top: 10px; text-align: center; border-bottom: 0; }
}

/* 尊重用户的减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; transition: none !important; }
}