*, *::before, *::after { box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif; font-size: 16px; line-height: 1.6; color: #1a1a2e; background-color: #EDEDED; background-image: radial-gradient(circle, #d4d4d4 1px, transparent 1px); background-size: 24px 24px; margin: 0; }
img { max-width: 100%; height: auto; display: block; }
a { color: #1F25DB; text-decoration: none; }
a:hover { color: #161BA8; text-decoration: underline; }
h1, h2, h3, h4, h5, h6 { margin: 0 0 16px 0; line-height: 1.3; color: #1a1a2e; }
p { margin: 0 0 16px 0; }
ul, ol { margin: 0 0 16px 0; padding-left: 20px; }
.wrapper { width: 100%; min-height: 100vh; display: flex; flex-direction: column; }
.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 16px; }
@media (min-width: 768px) {
  .container { padding: 0 24px; }
}
@media (min-width: 1200px) {
  .container { padding: 0 32px; }
}
.back-to-top { position: fixed; bottom: 24px; right: 24px; width: 44px; height: 44px; background-color: #1F25DB; color: #ffffff; font-size: 20px; border-radius: 50%; display: flex; align-items: center; justify-content: center; cursor: pointer; opacity: 0; visibility: hidden; transition: all 0.3s; box-shadow: 0 2px 10px rgba(31, 37, 219, 0.3); z-index: 150; }
.back-to-top.visible { opacity: 1; visibility: visible; }
.back-to-top:hover { background-color: #161BA8; transform: translateY(-2px); box-shadow: 0 4px 16px rgba(31, 37, 219, 0.4); }