/* Scroll-reactive background */
.sissei-bg {
    position: fixed;
    inset: 0;
    z-index: -10;
    pointer-events: none;
    background: linear-gradient(
    180deg,
    #ffffff 0%,
    #f5f7fa 18%,   /* Apple soft white */
    #e1e9f2 42%,   /* cool blue, very Apple */
    #d2dedc 70%,   /* Hermès mineral sage */
    #c9d6d3 100%   /* muted, elegant, quiet */
  );
    background-size: 100% 300%;
    transition: background-position 0.4s ease-out;
    background-position: 0 0;
  }
  
  /* SECTIONS */
    section {
    padding: 6rem 2rem;
    max-width: 1100px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
  }
  
    section::before {
    content: "";
    position: absolute;
    top: -40px;
    left: 50%;
    transform: translateX(-50%);
    width: 80%;
    height: 120%;
    background: radial-gradient(
      circle,
      rgba(51,102,153,0.10),
      rgba(255,255,255,0) 70%
    );
    opacity: 0;
    transition: opacity 0.8s ease;
    pointer-events: none;
    z-index: -1;
  }
  
  section.in-view::before {
    opacity: 1;
  }
  
  /* Section headers */
  .section-header {
    padding-left: 0;
  }
  
  .section-header h2 {
    font-size: 2.4rem;
    margin-bottom: 0.8rem;
    color: #28507a;
  }
  
  .section-header p {
    margin-bottom: 1rem;
    font-size: 1.1rem;
    color: var(--muted);
    max-width: 640px;
  }