:root {
    --bg-color: #0f172a;
    --text-color: #f8fafc;
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --secondary: #8b5cf6;
    --success: #10b981;
    --error: #ef4444;
    --card-bg: rgba(30, 41, 59, 0.7);
    --border-color: rgba(148, 163, 184, 0.2);
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Outfit', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* Background Animated Blobs */
.background-blobs {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
    filter: blur(80px);
    opacity: 0.5;
}

.blob {
    position: absolute;
    border-radius: 50%;
    animation: float 20s infinite ease-in-out alternate;
}

.shape1 {
    width: 400px;
    height: 400px;
    background: var(--primary);
    top: -100px;
    left: -100px;
}

.shape2 {
    width: 500px;
    height: 500px;
    background: var(--secondary);
    bottom: -100px;
    right: -100px;
    animation-delay: -5s;
}

.shape3 {
    width: 300px;
    height: 300px;
    background: var(--success);
    top: 40%;
    left: 40%;
    animation-delay: -10s;
}

@keyframes float {
    0% { transform: translate(0, 0) rotate(0deg) scale(1); }
    100% { transform: translate(100px, 150px) rotate(180deg) scale(1.2); }
}

.app-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

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

header h1 {
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(135deg, #60a5fa, #c084fc);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

header p {
    font-size: 1.1rem;
    color: #cbd5e1;
    margin-bottom: 1.5rem;
}

.score-board {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    margin-top: 1rem;
}

#score {
    font-size: 1.5rem;
    font-weight: 600;
    padding: 0.5rem 1.5rem;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 50px;
    box-shadow: var(--glass-shadow);
    backdrop-filter: blur(10px);
}

button {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 50px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
}

button:hover {
    transform: translateY(-2px) scale(1.05);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.6);
}

.hidden {
    display: none !important;
}

main {
    display: grid;
    grid-template-columns: 1fr;
    gap: 3rem;
    animation: fadeInUp 0.8s ease 0.2s both;
}

.drag-section {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 2rem;
    backdrop-filter: blur(15px);
    box-shadow: var(--glass-shadow);
}

.drag-section h2 {
    margin-bottom: 1.5rem;
    font-weight: 600;
    font-size: 1.2rem;
    text-align: center;
    color: #94a3b8;
}

.items-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    min-height: 120px;
}

/* Draggable Items */
.hardware-item {
    min-width: 130px;
    height: 100px;
    cursor: pointer; /* Ubah dari grab ke pointer agar kursor berbentuk tangan menunjuk */
    user-select: none;
    touch-action: none;
    perspective: 1000px;
    position: relative;
    transition: transform 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.hw-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    transform-style: preserve-3d;
}

.hardware-item.flipped .hw-inner {
    transform: rotateY(180deg);
}

.hw-front, .hw-back {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 12px;
}

.hw-front {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem;
    background: linear-gradient(145deg, #1e293b, #0f172a);
    border: 1px solid #334155;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: all 0.2s;
}

.hw-back {
    transform: rotateY(180deg);
    padding: 8px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
}

.hw-back img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 8px;
}

.remove-btn {
    position: absolute;
    top: -8px;
    right: -8px;
    width: 24px;
    height: 24px;
    background: var(--error);
    color: white;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0,0,0,0.3);
    transition: transform 0.2s;
    z-index: 10;
}
.remove-btn:hover { transform: scale(1.15); }
.remove-btn i { color: white !important; font-size: 0.8rem !important; }

.hardware-item:hover { transform: translateY(-5px); }

.hardware-item:hover .hw-front {
    border-color: var(--primary);
    box-shadow: 0 10px 20px rgba(59, 130, 246, 0.2);
}

.hardware-item:active {
    cursor: grabbing;
    transform: scale(0.95);
}

.hardware-item.dragging .hw-front {
    opacity: 0.7;
    border-color: var(--secondary);
    box-shadow: 0 0 20px rgba(139, 92, 246, 0.5);
    z-index: 100;
}

.hardware-item.dragging { z-index: 100; }

.hardware-item i {
    font-size: 2rem;
    color: #94a3b8;
    transition: color 0.3s ease;
}

.hardware-item:hover i { color: #38bdf8; }

.hardware-item span {
    font-size: 0.9rem;
    font-weight: 500;
    text-align: center;
}

/* Drop Section */
.drop-section {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.category {
    background: var(--card-bg);
    border: 2px dashed #475569;
    border-radius: 20px;
    display: flex;
    flex-direction: column;
    transition: all 0.3s;
    backdrop-filter: blur(10px);
    box-shadow: var(--glass-shadow);
}

.category-header {
    padding: 1rem;
    text-align: center;
    border-bottom: 1px solid rgba(148, 163, 184, 0.1);
    background: rgba(15, 23, 42, 0.5);
    border-radius: 18px 18px 0 0;
}

.category-header i {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--primary);
}

.category-header h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: #e2e8f0;
}

.drop-zone {
    padding: 1rem;
    min-height: 250px;
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
    transition: background 0.3s;
    flex-grow: 1;
}

/* Custom Category Colors */
.category[data-category="input"] { border-color: #3b82f6; }
.category[data-category="input"] .category-header { background: rgba(59, 130, 246, 0.1); border-bottom-color: rgba(59, 130, 246, 0.2); }
.category[data-category="input"] .category-header i, .category[data-category="input"] .category-header h3 { color: #60a5fa; }
.category[data-category="input"].drag-over { background: rgba(59, 130, 246, 0.15); box-shadow: 0 0 20px rgba(59, 130, 246, 0.3); }

.category[data-category="proses"] { border-color: #10b981; }
.category[data-category="proses"] .category-header { background: rgba(16, 185, 129, 0.1); border-bottom-color: rgba(16, 185, 129, 0.2); }
.category[data-category="proses"] .category-header i, .category[data-category="proses"] .category-header h3 { color: #34d399; }
.category[data-category="proses"].drag-over { background: rgba(16, 185, 129, 0.15); box-shadow: 0 0 20px rgba(16, 185, 129, 0.3); }

.category[data-category="output"] { border-color: #f97316; }
.category[data-category="output"] .category-header { background: rgba(249, 115, 22, 0.1); border-bottom-color: rgba(249, 115, 22, 0.2); }
.category[data-category="output"] .category-header i, .category[data-category="output"] .category-header h3 { color: #fb923c; }
.category[data-category="output"].drag-over { background: rgba(249, 115, 22, 0.15); box-shadow: 0 0 20px rgba(249, 115, 22, 0.3); }

.category[data-category="penyimpanan"] { border-color: #ec4899; }
.category[data-category="penyimpanan"] .category-header { background: rgba(236, 72, 153, 0.1); border-bottom-color: rgba(236, 72, 153, 0.2); }
.category[data-category="penyimpanan"] .category-header i, .category[data-category="penyimpanan"] .category-header h3 { color: #f472b6; }
.category[data-category="penyimpanan"].drag-over { background: rgba(236, 72, 153, 0.15); box-shadow: 0 0 20px rgba(236, 72, 153, 0.3); }

.category[data-category="tambahan"] { border-color: #eab308; }
.category[data-category="tambahan"] .category-header { background: rgba(234, 179, 8, 0.1); border-bottom-color: rgba(234, 179, 8, 0.2); }
.category[data-category="tambahan"] .category-header i, .category[data-category="tambahan"] .category-header h3 { color: #facc15; }
.category[data-category="tambahan"].drag-over { background: rgba(234, 179, 8, 0.15); box-shadow: 0 0 20px rgba(234, 179, 8, 0.3); }

/* Generic drag hover effects */
.category.drag-over {
    transform: scale(1.02);
}

.hardware-item.dropped {
    cursor: default;
    width: 100%;
}

.hardware-item.dropped:hover {
    transform: none;
    box-shadow: none;
}

/* Dropped Input - Blue */
.hardware-item.dropped[data-category="input"] .hw-front,
.hardware-item.dropped[data-category="input"] .hw-back {
    background: linear-gradient(145deg, rgba(59, 130, 246, 0.15), rgba(59, 130, 246, 0.05));
    border-color: #3b82f6;
}
.hardware-item.dropped[data-category="input"] i { color: #60a5fa; }

/* Dropped Proses - Green */
.hardware-item.dropped[data-category="proses"] .hw-front,
.hardware-item.dropped[data-category="proses"] .hw-back {
    background: linear-gradient(145deg, rgba(16, 185, 129, 0.15), rgba(16, 185, 129, 0.05));
    border-color: #10b981;
}
.hardware-item.dropped[data-category="proses"] i { color: #34d399; }

/* Dropped Output - Orange */
.hardware-item.dropped[data-category="output"] .hw-front,
.hardware-item.dropped[data-category="output"] .hw-back {
    background: linear-gradient(145deg, rgba(249, 115, 22, 0.15), rgba(249, 115, 22, 0.05));
    border-color: #f97316;
}
.hardware-item.dropped[data-category="output"] i { color: #fb923c; }

/* Dropped Penyimpanan - Pink */
.hardware-item.dropped[data-category="penyimpanan"] .hw-front,
.hardware-item.dropped[data-category="penyimpanan"] .hw-back {
    background: linear-gradient(145deg, rgba(236, 72, 153, 0.15), rgba(236, 72, 153, 0.05));
    border-color: #ec4899;
}
.hardware-item.dropped[data-category="penyimpanan"] i { color: #f472b6; }

/* Dropped Tambahan - Yellow */
.hardware-item.dropped[data-category="tambahan"] .hw-front,
.hardware-item.dropped[data-category="tambahan"] .hw-back {
    background: linear-gradient(145deg, rgba(234, 179, 8, 0.15), rgba(234, 179, 8, 0.05));
    border-color: #eab308;
}
.hardware-item.dropped[data-category="tambahan"] i { color: #facc15; }

.item-wrong {
    animation: shake 0.5s cubic-bezier(.36,.07,.19,.97) both;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(5px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 1;
    transition: opacity 0.3s ease;
}

.modal.hidden {
    opacity: 0;
    pointer-events: none;
}

.modal-content {
    background: linear-gradient(135deg, #1e293b, #0f172a);
    padding: 3rem;
    border-radius: 24px;
    text-align: center;
    border: 1px solid var(--border-color);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5), 0 0 40px rgba(16, 185, 129, 0.2);
    transform: scale(1);
    transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.modal.hidden .modal-content {
    transform: scale(0.8);
}

.modal h2 {
    font-size: 2.5rem;
    color: var(--success);
    margin-bottom: 1rem;
}

.modal p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    color: #cbd5e1;
}

/* Animations */
@keyframes shake {
    10%, 90% { transform: translate3d(-1px, 0, 0); }
    20%, 80% { transform: translate3d(2px, 0, 0); }
    30%, 50%, 70% { transform: translate3d(-4px, 0, 0); }
    40%, 60% { transform: translate3d(4px, 0, 0); }
}

@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-30px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Responsive */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }
    
    .drop-section {
        grid-template-columns: 1fr;
    }
    
    .hardware-item {
        min-width: 100px;
        padding: 0.8rem;
    }
}

.top-controls {
    position: absolute;
    top: 20px;
    right: 20px;
    display: flex;
    gap: 10px;
    z-index: 100;
}

/* Action Button */
.theme-btn {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    color: #eab308;
    font-size: 1.2rem;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    backdrop-filter: blur(10px);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: all 0.3s;
}
.theme-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 12px rgba(0,0,0,0.15);
}

/* --- LIGHT MODE --- */
body.light-mode {
    --bg-color: #f1f5f9;
    --text-color: #0f172a;
    --card-bg: rgba(255, 255, 255, 0.7);
    --border-color: rgba(148, 163, 184, 0.5);
    --glass-shadow: 0 8px 32px 0 rgba(148, 163, 184, 0.2);
}

body.light-mode .background-blobs {
    opacity: 0.4;
}

body.light-mode header p {
    color: #334155;
}

body.light-mode .drag-section h2 {
    color: #475569;
}

body.light-mode .hw-front {
    background: linear-gradient(145deg, #ffffff, #f8fafc);
    border-color: #cbd5e1;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

body.light-mode .hw-back {
    background: #ffffff;
    border-color: #cbd5e1;
}

body.light-mode .hardware-item:hover .hw-front {
    box-shadow: 0 10px 20px rgba(59, 130, 246, 0.15);
}

body.light-mode .hardware-item i {
    color: #475569;
}

body.light-mode .hardware-item span {
    color: #0f172a;
}

body.light-mode .category-header {
    background: rgba(255, 255, 255, 0.6);
}

body.light-mode .category-header h3 {
    color: #0f172a;
}

body.light-mode #header-congrats {
    color: #059669 !important; /* darker green for light mode */
}

/* Global Back Button Style (Materi, Permainan, Aktivitas) */
.back-btn {
    display: inline-block;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s;
}

.back-btn:hover {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

/* Material Page Hardware Cards */
.hardware-card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 2rem;
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
    min-height: 280px;
    justify-content: center;
}

/* Flip Animation */
.flip-card {
    background-color: transparent;
    perspective: 1000px;
    min-height: 280px;
}

.flip-card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.6s;
    transform-style: preserve-3d;
    cursor: pointer;
}

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

.flip-card-front, .flip-card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    border-radius: 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
}

.flip-card-back {
    transform: rotateY(180deg);
    overflow: hidden;
    padding: 0;
}

.flip-card-back img {
    width: 100%;
    height: 100%;
    object-fit: contain; /* Memastikan gambar tidak terpotong (zoom) atau gepeng */
    border-radius: 12px;
    padding: 10px; /* Jarak aman agar gambar tidak menempel ke tepi */
    background: var(--card-bg); /* Menjaga konsistensi warna latar */
}

.flip-card-hint {
    font-size: 0.75rem;
    margin-top: 1rem;
    opacity: 0.6;
    font-style: italic;
}