:root {
            --primary: #2c3e50;
            --accent: #3498db;
            --bg: #ecf0f1;
            --card-bg: #ffffff;
            --text: #2c2c2c;
            --shadow: rgba(44, 62, 80, 0.15);
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Outfit', sans-serif;
            background: linear-gradient(135deg, #ecf0f1 0%, #d5dbdd 100%);
            min-height: 100vh;
            overflow-x: hidden;
            position: relative;
        }

        body::before {
            content: '';
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: 
                radial-gradient(circle at 20% 50%, rgba(52, 152, 219, 0.08) 0%, transparent 50%),
                radial-gradient(circle at 80% 80%, rgba(44, 62, 80, 0.08) 0%, transparent 50%);
            pointer-events: none;
            z-index: 0;
        }

        .app-container {
            position: relative;
            z-index: 1;
            max-width: 1200px;
            margin: 0 auto;
            padding: 2rem;
        }

        header {
            text-align: center;
            margin-bottom: 2rem;
            animation: fadeIn 0.8s ease-out;
        }

        h1 {
            font-family: 'DM Serif Display', serif;
            font-size: 3rem;
            color: var(--primary);
            margin-bottom: 0.5rem;
            letter-spacing: -0.02em;
            font-style: italic;
        }

        .subtitle {
            font-size: 1.1rem;
            color: var(--text);
            font-weight: 300;
            letter-spacing: 0.05em;
            text-transform: uppercase;
        }

        .filters-container {
            background: var(--card-bg);
            padding: 1.5rem;
            border: 2px solid var(--primary);
            margin-bottom: 2rem;
            animation: fadeIn 1s ease-out 0.2s both;
        }

        .filter-section {
            margin-bottom: 1.5rem;
        }

        .filter-section:last-child {
            margin-bottom: 0;
        }

        .filter-label {
            font-weight: 600;
            font-size: 0.9rem;
            color: var(--primary);
            text-transform: uppercase;
            letter-spacing: 0.05em;
            margin-bottom: 0.75rem;
            display: block;
        }

        .checkbox-group {
            display: flex;
            flex-wrap: wrap;
            gap: 1rem;
        }

        .checkbox-item {
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .checkbox-item input[type="checkbox"] {
            width: 18px;
            height: 18px;
            cursor: pointer;
        }

        .checkbox-item label {
            cursor: pointer;
            font-size: 0.95rem;
            color: var(--text);
        }

        .filter-warning {
            font-size: 0.75rem;
            color: #888;
            font-style: italic;
            margin-top: 1rem;
            text-align: center;
        }

        .controls {
            display: flex;
            justify-content: center;
            gap: 1rem;
            margin-bottom: 2rem;
            flex-wrap: wrap;
        }

        .btn {
            padding: 0.8rem 2rem;
            border: 2px solid var(--primary);
            background: var(--card-bg);
            color: var(--primary);
            font-family: 'Outfit', sans-serif;
            font-weight: 600;
            font-size: 1rem;
            cursor: pointer;
            transition: all 0.3s ease;
            position: relative;
            overflow: hidden;
            text-transform: uppercase;
            letter-spacing: 0.05em;
        }

        .btn::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: var(--primary);
            transition: left 0.3s ease;
            z-index: -1;
        }

        .btn:hover::before {
            left: 0;
        }

        .btn:hover {
            color: var(--accent);
            border-color: var(--primary);
        }

        .btn.active {
            background: var(--primary);
            color: var(--card-bg);
        }

        .progress {
            text-align: center;
            margin-bottom: 2rem;
            font-size: 1.1rem;
            color: var(--text);
            font-weight: 400;
            animation: fadeIn 1.2s ease-out 0.4s both;
        }

        .progress strong {
            color: var(--accent);
            font-weight: 800;
        }

        .flashcard-container {
            perspective: 1000px;
            margin: 0 auto 2rem;
            max-width: 500px;
            height: 600px;
            animation: slideUp 1s ease-out 0.6s both;
            display: flex;
            align-items: center;
            justify-content: center;
            position: relative;
        }

        .flash-overlay {
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: var(--primary);
            opacity: 0;
            pointer-events: none;
            z-index: 10;
            transition: opacity 0.1s ease;
        }

        .flash-overlay.active {
            opacity: 1;
        }

        .flashcard {
            width: 100%;
            height: 600px;
            position: relative;
            transform-style: preserve-3d;
            transition: transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
            cursor: pointer;
        }

        .flashcard.flipped {
            transform: rotateY(180deg);
        }

        .card-face {
            position: absolute;
            width: 100%;
            height: 100%;
            backface-visibility: hidden;
            background: var(--card-bg);
            border: 3px solid var(--primary);
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            padding: 0;
            box-shadow: 
                0 20px 60px var(--shadow),
                0 0 0 1px rgba(255, 255, 255, 0.5) inset;
            top: 0;
            left: 0;
        }

        .card-front {
            position: relative;
        }

        .card-front::before {
            content: '';
            position: absolute;
            top: 1rem;
            left: 1rem;
            right: 1rem;
            bottom: 1rem;
            border: 1px solid var(--accent);
            opacity: 0.3;
            pointer-events: none;
        }

        .card-back {
            transform: rotateY(180deg);
            background: linear-gradient(135deg, var(--primary) 0%, #34495e 100%);
            color: var(--card-bg);
            border-color: var(--accent);
        }

        .card-back::before {
            content: '';
            position: absolute;
            top: 1rem;
            left: 1rem;
            right: 1rem;
            bottom: 1rem;
            border: 1px solid var(--accent);
            opacity: 0.5;
            pointer-events: none;
        }

        .card-content {
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            height: 100%;
            width: 100%;
            padding: 2rem;
        }

        .faculty-image {
            width: 280px;
            height: 320px;
            object-fit: cover;
            border: 4px solid var(--primary);
            box-shadow: 
                0 10px 30px rgba(0, 0, 0, 0.2),
                0 0 0 8px rgba(52, 152, 219, 0.2);
            margin-bottom: 1.5rem;
            transition: transform 0.3s ease;
        }

        .flashcard:hover .faculty-image {
            transform: translateY(-5px);
        }

        .card-hint {
            font-size: 0.9rem;
            color: var(--text);
            opacity: 0;
            text-transform: uppercase;
            letter-spacing: 0.1em;
            transition: opacity 0.3s ease;
        }

        .flashcard:hover .card-hint {
            opacity: 0.5;
        }

        .faculty-name {
            font-family: 'Outfit', sans-serif;
            font-size: 2rem;
            color: var(--card-bg);
            margin-bottom: 1rem;
            font-weight: 600;
            line-height: 1.2;
            text-align: center;
        }

        .faculty-departments {
            font-size: 1rem;
            line-height: 1.6;
            font-weight: 400;
            text-align: center;
            margin-bottom: 1rem;
        }

        .dept-tag {
            display: inline;
        }

        .dept-biology { color: #27ae60; }
        .dept-chemistry { color: #e74c3c; }
        .dept-cs { color: #9b59b6; }
        .dept-engineering { color: #e67e22; }
        .dept-hixon { color: #1abc9c; }
        .dept-hsa { color: #f39c12; }
        .dept-mathematics { color: #3498db; }
        .dept-physics { color: #00bcd4; }

        .faculty-title {
            font-size: 1.1rem;
            color: var(--card-bg);
            line-height: 1.6;
            font-weight: 300;
            white-space: pre-line;
            opacity: 0.95;
            margin-bottom: 1rem;
            text-align: center;
        }

        .faculty-education {
            font-size: 0.9rem;
            color: var(--card-bg);
            opacity: 0.75;
            font-weight: 300;
            font-style: italic;
            text-align: center;
        }

        .faculty-education::before {
            content: '(';
        }

        .faculty-education::after {
            content: ')';
        }

        .navigation {
            display: flex;
            justify-content: center;
            gap: 1rem;
            animation: fadeIn 1.4s ease-out 0.8s both;
        }

        .nav-btn {
            padding: 1rem 2.5rem;
            border: 2px solid var(--primary);
            background: var(--card-bg);
            color: var(--primary);
            font-family: 'Outfit', sans-serif;
            font-weight: 600;
            font-size: 1.1rem;
            cursor: pointer;
            transition: all 0.3s ease;
            position: relative;
            overflow: hidden;
            text-transform: uppercase;
            letter-spacing: 0.05em;
        }

        .nav-btn::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: var(--primary);
            transition: left 0.3s ease;
            z-index: -1;
        }

        .nav-btn:hover::before {
            left: 0;
        }

        .nav-btn:hover {
            color: var(--accent);
        }

        .nav-btn:disabled {
            opacity: 0.3;
            cursor: not-allowed;
        }

        .nav-btn:disabled:hover {
            color: var(--primary);
            background: var(--card-bg);
        }

        .nav-btn:disabled::before {
            left: -100%;
        }

        @keyframes fadeIn {
            from {
                opacity: 0;
                transform: translateY(-20px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        @keyframes slideUp {
            from {
                opacity: 0;
                transform: translateY(50px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        @media (max-width: 768px) {
            h1 {
                font-size: 2.5rem;
            }

            .flashcard-container {
                height: 550px;
            }

            .flashcard {
                height: 550px;
            }

            .faculty-image {
                width: 220px;
                height: 260px;
            }

            .card-content {
                padding: 1.5rem;
            }

            .faculty-name {
                font-size: 1.6rem;
            }

            .faculty-title {
                font-size: 1rem;
            }
        }

        .no-results {
            text-align: center;
            padding: 3rem;
            color: var(--text);
            font-size: 1.2rem;
        }