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

html, body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background-color: #f7f7f9;
  color: #111827;
}

/* ---- Layout ---- */
body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

main {
  flex: 1;
  max-width: 1040px;       
  width: 100%;
  margin: 7.5rem auto 3rem;
  padding: 0 1.75rem;       
}

.main-wide {
  max-width: 1200px;
}

/* ---- Navbar ---- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 72px;
  background-color: #111827;
  color: white;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 8rem;
  z-index: 100;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.navbar .logo a {
  text-decoration: none;
  font-weight: 600;
  font-size: 1.1rem;
  color: white;
}

.nav-links {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 4rem;
}

.nav-links a,
.nav-links button {
  color: #e5e7eb;
  text-decoration: none;
  font-size: 0.95rem;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.3rem 0;
}

.nav-links a:hover,
.nav-links button:hover {
  color: white;
}

/* ---- Dropdown ---- */
.dropdown {
  position: relative;
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  background-color: #111827;
  padding: 0.5rem 0;
  min-width: 100px;
  border-radius: 0.5rem;
  display: none;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
}

.dropdown:hover .dropdown-menu {
  display: block;
  padding: 0.55rem 1.25rem;
  font-size: 0.95rem;
}

.dropdown-menu a {
  display: block;
  padding: 0.5rem 1rem;
  font-size: 0.9rem;
}

.dropdown-menu a:hover {
  background-color: #1f2937;
}

/* ---- 通用页面标题 ---- */
.page-header {
  margin-bottom: 2rem;
}

.page-header h1 {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

.page-header p {
  font-size: 0.95rem;
  color: #6b7280;
}

/* ---- Cards ---- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.25rem;
  margin-top: 1rem;
}

.card {
  background-color: white;
  border-radius: 0.75rem;
  padding: 1.25rem 1.3rem;
  box-shadow: 0 1px 6px rgba(15, 23, 42, 0.06);
  margin: 3rem 0;  
}

.card h2 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

.card p {
  font-size: 0.95rem;
  color: #4b5563;
}

/* ---- Lists ---- */
ul.simple-list {
  margin-top: 0.5rem;
  padding-left: 1.2rem;
  font-size: 0.95rem;
  color: #4b5563;
}

ul.simple-list li + li {
  margin-top: 0.25rem;
}

/* ---- Footer ---- */
footer {
  text-align: center;
  font-size: 0.8rem;
  color: #9ca3af;
  padding: 1.5rem 0 2rem;
}

/* ---- Mobile Navbar ---- */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: #e5e7eb;
  font-size: 1.4rem;
  cursor: pointer;
}

@media (max-width: 720px) {
  .nav-links {
    position: fixed;
    top: 64px;
    right: 0;
    left: 0;
    background-color: #111827;
    flex-direction: column;
    align-items: flex-start;
    padding: 0.75rem 1.5rem 1.25rem;
    gap: 0.5rem;
    display: none;
  }

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

  .dropdown-menu {
    position: static;
    box-shadow: none;
    padding-left: 0.5rem;
  }

  .dropdown:hover .dropdown-menu {
    display: none; 
  }

  .menu-toggle {
    display: block;
  }
}