/* Βασικά */
* { box-sizing: border-box; }
body { font-family: 'Play', sans-serif; }

/* Background */
.gradient-bg {
  background: linear-gradient(135deg, #E8F4FD 0%, #F0E6FF 50%, #FFF9E6 100%);
}

/* Cards / Hover / Buttons */
.card-hover { transition: all .3s ease; }
.card-hover:hover { transform: translateY(-8px); box-shadow: 0 20px 40px rgba(0,0,0,.1); }

.btn-bounce { transition: all .2s ease; }
.btn-bounce:hover { transform: scale(1.05); }

/* Floating icons */
.floating-animation { animation: float 3s ease-in-out infinite; }
@keyframes float {
  0%,100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* Pages (SPA-like) */
.page { display: none; }
.page.active { display: block; }

/* Filter buttons */
.filter-btn { transition: all .2s ease; }
.filter-btn.active {
  background: linear-gradient(135deg, #3B82F6, #8B5CF6);
  color: #fff;
  transform: scale(1.05);
}

/* Subject borders (προαιρετικά) */
.subject-greek { border-left: 4px solid #EC4899; }     /* Γλώσσα - Ροζ */
.subject-math { border-left: 4px solid #3B82F6; }      /* Μαθηματικά - Μπλε */
.subject-science { border-left: 4px solid #10B981; }   /* Φυσικές Επιστήμες - Πράσινο */
.subject-geography { border-left: 4px solid #F59E0B; } /* Γεωγραφία - Πορτοκαλί */
.subject-history { border-left: 4px solid #EF4444; } /* Ιστορία - Κοκκινωπό */
.subject-english { border-left: 4px solid #06B6D4; }   /* Αγγλικά - Κυανό */