body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; }
        
        /* --- EFEKTLER --- */
        .card-perspective { perspective: 1000px; }
        
        .card-inner {
            position: relative;
            width: 100%;
            height: 100%;
            text-align: center;
            transition: transform 0.6s cubic-bezier(0.4, 0.0, 0.2, 1);
            transform-style: preserve-3d;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
        }
        /* --- EZBER KARTLARI DÜZELTME (YENİ) --- */
        .flashcard-scene {
            perspective: 1000px;
            width: 100%;
            height: 320px;
            display: flex;
            justify-content: center;
        }

        .flashcard-inner {
            width: 100%;
            max-width: 600px;
            height: 100%;
            position: relative;
            transition: transform 0.8s;
            transform-style: preserve-3d;
            cursor: pointer;
        }

        /* JavaScript bu class'ı eklediğinde kart dönecek */
        .flashcard-inner.is-flipped {
            transform: rotateY(180deg);
        }

        .flashcard-face {
            position: absolute;
            width: 100%;
            height: 100%;
            -webkit-backface-visibility: hidden; /* Safari için */
            backface-visibility: hidden;
            border-radius: 1rem;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            padding: 2rem;
            box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
        }

        .flashcard-front {
            background-color: white;
            border: 2px solid #e9d5ff; /* Morumsu sınır */
            color: #333;
            transform: rotateY(0deg); /* Ön yüz düz durur */
            z-index: 2;
        }

        .flashcard-back {
            background-color: #9333ea; /* Koyu Mor arka plan */
            color: white;
            transform: rotateY(180deg); /* Arka yüz baştan ters durur */
            z-index: 1;
        }

        .card-flipped .card-inner { transform: rotateY(180deg); }

        .card-front, .card-back {
            position: absolute;
            width: 100%;
            height: 100%;
            -webkit-backface-visibility: hidden;
            backface-visibility: hidden;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            border-radius: 0.75rem;
            padding: 1.5rem;
            top: 0;
            left: 0;
            user-select: none;
        }

        .card-front { z-index: 2; transform: rotateY(0deg); }
        .card-back { transform: rotateY(180deg); overflow-y: auto; z-index: 1; }
        .card-flipped .card-back { z-index: 3; }

        .chart-container {
            position: relative;
            width: 100%;
            max-width: 500px;
            height: 300px;
            max-height: 300px;
            margin: 0 auto;
        }

        /* Animasyonlar */
        @keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
        .quiz-anim { animation: fadeIn 0.4s ease-out forwards; }
        
        @keyframes slideIn { from { transform: translateX(-20px); opacity: 0; } to { transform: translateX(0); opacity: 1; } }
        .anim-slide { animation: slideIn 0.3s ease-out forwards; }

        @keyframes pulse-green { 0% { box-shadow: 0 0 0 0 rgba(74, 222, 128, 0.7); } 70% { box-shadow: 0 0 0 10px rgba(74, 222, 128, 0); } 100% { box-shadow: 0 0 0 0 rgba(74, 222, 128, 0); } }
        .pulse-success { animation: pulse-green 0.5s; }

        @keyframes shake { 0%, 100% { transform: translateX(0); } 25% { transform: translateX(-5px); } 75% { transform: translateX(5px); } }
        .anim-shake { animation: shake 0.3s; }

        .custom-scrollbar::-webkit-scrollbar { width: 4px; }
        .custom-scrollbar::-webkit-scrollbar-thumb { background: #444; }