/* ===========================================================
   GLOBAL PAGE STYLE
   =========================================================== */

body {
  margin: 0;
  padding: 0;
  background: #001a33;
  font-family: "Segoe UI", sans-serif;
  color: white;
  text-align: center;
}

/* MAIN TITLE */
.page-title {
  margin-top: 60px;
  font-size: 48px;
  font-weight: 600;
  letter-spacing: 2px;
}

/* 2×2 GRID (HOME PAGE) */
.tile-grid {
  margin: 60px auto;
  width: 90%;
  max-width: 900px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 40px;
}

/* 4×4 GRID (TEACHER TOOLS) */
.tile-grid-4x4 {
  margin: 60px auto;
  width: 90%;
  max-width: 1200px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 30px;
}

/* FROSTED GLASS TILE */
.frost-tile {
  height: 160px;
  border-radius: 22px;
  background: rgba(255, 255, 255, 0.13);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.18);
  box-shadow:
    inset 0 0 25px rgba(255, 255, 255, 0.1),
    0 8px 25px rgba(0, 0, 0, 0.5);
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 20px;
  font-weight: 500;
  cursor: pointer;
  transition: 0.25s ease;
}

.frost-tile:hover {
  transform: scale(1.05);
  background: rgba(255, 255, 255, 0.25);
  box-shadow:
    inset 0 0 25px rgba(255, 255, 255, 0.15),
    0 12px 35px rgba(0, 0, 0, 0.6);
}

/* LINKS INSIDE TILES */
.tile-link {
  text-decoration: none;
  color: white;
  display: flex;
}

/* BACK BUTTON */
.back-box {
  position: absolute;
  top: 20px;
  left: 20px;
  background: rgba(255,255,255,0.18);
  padding: 10px 20px;
  border-radius: 10px;
  font-size: 18px;
  cursor: pointer;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.3);
  transition: 0.25s ease;
}

.back-box:hover {
  background: rgba(255,255,255,0.28);
  transform: scale(1.05);
}