/* ============================================================
   yfwis 品牌官网样式
   品牌蓝 #007AFF（唯一强调色） · 底色 #F5F6F8
   响应式：桌面 / 平板 / 手机
   ============================================================ */

:root {
  --blue: #007AFF;
  --blue-dark: #0060CC;
  --blue-deep: #004EAB;
  --blue-soft: #E8F2FF;
  --bg: #F5F6F8;
  --ink: #1A1D29;
  --ink-soft: #4A5060;
  --ink-light: #6B7280;
  --white: #FFFFFF;
  --line: #E4E7EC;
  --radius: 16px;
  --shadow: 0 12px 32px rgba(0, 122, 255, 0.10);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* ===== 顶部导航 ===== */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

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

.brand-logo {
  width: 40px; height: 40px;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0, 122, 255, 0.18);
}

.brand-name {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: 0.5px;
}

.brand-dot { color: var(--blue); margin: 0 2px; }

.nav-links { display: flex; align-items: center; gap: 28px; }

.nav-links a {
  font-size: 15px;
  color: var(--ink-soft);
  transition: color 0.2s;
}

.nav-links a:hover { color: var(--blue); }

.nav-links .nav-cta {
  color: var(--white);
  background: var(--blue);
  padding: 8px 18px;
  border-radius: 999px;
  font-weight: 600;
}

.nav-links .nav-cta:hover { background: var(--blue-dark); color: var(--white); }

/* 汉堡按钮（默认隐藏） */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 6px;
}

.nav-toggle span {
  width: 22px; height: 2px;
  background: var(--ink);
  border-radius: 2px;
  transition: 0.25s;
}

/* ===== 首屏 Hero ===== */
.hero {
  position: relative;
  padding: 120px 20px 88px;
  background:
    radial-gradient(1200px 500px at 80% -10%, rgba(0, 122, 255, 0.16), transparent 60%),
    radial-gradient(900px 420px at 10% 110%, rgba(0, 122, 255, 0.10), transparent 60%),
    linear-gradient(180deg, #F8FBFF 0%, var(--bg) 100%);
  text-align: center;
}

.hero-inner { max-width: 880px; margin: 0 auto; }

.hero-mascot {
  width: 260px; height: 260px;
  margin: 0 auto 34px;
}

.hero-eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  color: var(--blue);
  background: var(--blue-soft);
  padding: 7px 20px;
  border-radius: 999px;
  letter-spacing: 3px;
  margin-bottom: 26px;
}

.hero-title {
  font-size: 40px;
  line-height: 1.35;
  font-weight: 800;
  letter-spacing: 2px;
  color: var(--ink);
  margin-bottom: 24px;
}

.hero-sub {
  font-size: 17px;
  color: var(--ink-soft);
  margin-bottom: 16px;
}

.hero-slogan {
  font-size: 14px;
  color: var(--ink-light);
  letter-spacing: 1.5px;
  margin-bottom: 40px;
}

.hero-actions { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }

.btn {
  display: inline-block;
  padding: 14px 34px;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 600;
  transition: all 0.2s;
}

.btn-primary { background: var(--blue); color: var(--white); }
.btn-primary:hover { background: var(--blue-dark); transform: translateY(-1px); }

.btn-ghost {
  background: var(--white);
  color: var(--blue);
  border: 1px solid var(--blue);
}

.btn-ghost:hover { background: var(--blue-soft); }

/* ===== 通用 section ===== */
.section { padding: 88px 20px; }
.section-head { text-align: center; margin-bottom: 52px; }

.section-kicker {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 5px;
  color: var(--blue);
  margin-bottom: 10px;
}

.section-title {
  font-size: 32px;
  font-weight: 800;
  letter-spacing: 1px;
  color: var(--ink);
  margin-bottom: 16px;
}

.section-desc { font-size: 16px; color: var(--ink-light); letter-spacing: 0.5px; }

/* ===== 产品卡片 ===== */
.products { max-width: 1100px; margin: 0 auto; }

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 40px 30px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: transform 0.25s, box-shadow 0.25s;
}

.card:hover { transform: translateY(-4px); box-shadow: 0 18px 40px rgba(0, 122, 255, 0.16); }

.card-icon {
  width: 64px; height: 64px;
  margin: 0 auto 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  color: var(--blue);
  background: var(--blue-soft);
  border-radius: 18px;
}

.card-title { font-size: 20px; font-weight: 700; margin-bottom: 12px; }
.card-text {
  font-size: 14.5px;
  color: var(--ink-light);
  line-height: 1.8;
  letter-spacing: 0.3px;
}

/* ===== 关于我们 ===== */
.about {
  background: var(--white);
  border-top: 1px solid var(--line);
}

.about-body { max-width: 760px; margin: 0 auto; }

.about-text {
  font-size: 16px;
  color: var(--ink-soft);
  line-height: 1.9;
  margin-bottom: 18px;
}

.about-text strong { color: var(--ink); }

/* ===== 页脚 ===== */
.footer {
  background: #12141C;
  color: #C7CBD6;
  padding: 52px 20px 44px;
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 20px;
}

.footer-brand { display: flex; align-items: center; gap: 12px; }
.footer-logo { width: 52px; height: 52px; border-radius: 12px; }
.footer-brand-name { font-size: 18px; font-weight: 700; color: var(--white); }

.footer-contact { font-size: 14px; line-height: 2.1; }

.footer-company { color: #E6E9F0; font-weight: 600; letter-spacing: 0.5px; }

.footer-copyright { color: #9AA0B0; letter-spacing: 0.3px; }

.footer-icp { margin-top: 4px; }

.footer-icp a {
  color: #9AA0B0;
  transition: color 0.2s;
}

.footer-icp a:hover { color: var(--blue); }

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .cards { grid-template-columns: 1fr; max-width: 520px; margin: 0 auto; }
}

@media (max-width: 760px) {
  .hero { padding: 104px 20px 64px; }
  .hero-title { font-size: 27px; letter-spacing: 1px; }
  .hero-sub { font-size: 16px; }
  .hero-mascot { width: 200px; height: 200px; }
  .section { padding: 64px 20px; }
  .section-title { font-size: 26px; }

  .nav-toggle { display: flex; }

  .nav-links {
    position: absolute;
    top: 64px; left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--white);
    border-bottom: 1px solid var(--line);
    padding: 12px 20px 20px;
    gap: 4px;
    display: none;
  }

  .nav-links.open { display: flex; }

  .nav-links a {
    padding: 12px 8px;
    border-radius: 10px;
    font-size: 16px;
  }

  .nav-links a:hover { background: var(--blue-soft); }

  .nav-links .nav-cta {
    text-align: center;
    margin-top: 8px;
  }

  .footer-inner { flex-direction: column; }
  .footer-contact { text-align: center; }
}