/* Data Structures Playground - Enhanced CSS */

:root {
    --ds-primary: #a259ff;
    --ds-secondary: #00f7ff;
    --ds-accent: #ff6b6b;
    --ds-success: #51cf66;
    --ds-warning: #ffd43b;
    --ds-bg-dark: #181a20;
    --ds-bg-medium: #232946;
    --ds-bg-light: #2d3748;
    --ds-text-primary: #ffffff;
    --ds-text-secondary: #e2e8f0;
    --ds-border: #a259ff;
    --ds-shadow: 0 8px 32px rgba(162, 89, 255, 0.25);
    --ds-transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --ds-animation-duration: 0.5s;
}

/* Main Container */
.data-structures-container {
    background: linear-gradient(135deg, var(--ds-bg-dark) 0%, var(--ds-bg-medium) 100%);
    border: 2.5px solid var(--ds-border);
    border-radius: 20px;
    padding: 2rem;
    color: var(--ds-text-primary);
    font-family: 'Orbitron', sans-serif;
    max-width: 900px;
    margin: 2rem auto;
    box-shadow: var(--ds-shadow);
    position: relative;
    overflow: hidden;
}

.data-structures-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--ds-primary), var(--ds-secondary), var(--ds-accent));
    animation: scan-line 3s linear infinite;
}

@keyframes scan-line {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

/* Header Section */
.ds-header {
    text-align: center;
    margin-bottom: 2rem;
    position: relative;
}

.ds-header h2 {
    color: var(--ds-primary);
    font-size: 2.5rem;
    font-weight: 900;
    letter-spacing: 3px;
    margin-bottom: 1rem;
    text-shadow: 0 0 20px var(--ds-primary);
    animation: glow 2s ease-in-out infinite alternate;
}

@keyframes glow {
    from { text-shadow: 0 0 20px var(--ds-primary); }
    to { text-shadow: 0 0 30px var(--ds-primary), 0 0 40px var(--ds-secondary); }
}

.ds-selector {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.ds-selector label {
    color: var(--ds-secondary);
    font-weight: 600;
    font-size: 1.1rem;
}

#ds-type {
    background: var(--ds-bg-medium);
    color: var(--ds-primary);
    border: 2px solid var(--ds-border);
    border-radius: 10px;
    padding: 0.75rem 1.5rem;
    font-family: 'Orbitron', sans-serif;
    font-size: 1rem;
    font-weight: 600;
    outline: none;
    transition: var(--ds-transition);
    cursor: pointer;
    min-width: 150px;
}

#ds-type:focus {
    border-color: var(--ds-secondary);
    box-shadow: 0 0 0 3px rgba(0, 247, 255, 0.3);
    transform: translateY(-2px);
}

#ds-type:hover {
    border-color: var(--ds-secondary);
    transform: translateY(-1px);
}

/* Visualization Area */
.ds-visualization {
    background: var(--ds-bg-medium);
    border-radius: 15px;
    padding: 2rem;
    margin: 1.5rem 0;
    min-height: 200px;
    border: 1px solid rgba(162, 89, 255, 0.3);
    position: relative;
    overflow: hidden;
}

.ds-visualization::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 20% 80%, rgba(162, 89, 255, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.ds-display {
    color: var(--ds-text-primary);
    font-family: 'Orbitron', sans-serif;
    font-size: 1.1rem;
    line-height: 1.6;
    position: relative;
    z-index: 1;
}

/* Controls Section */
.ds-controls {
    display: flex;
    gap: 1rem;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    margin-top: 1.5rem;
}

#ds-input {
    background: var(--ds-bg-medium);
    color: var(--ds-text-primary);
    border: 2px solid var(--ds-border);
    border-radius: 10px;
    padding: 0.75rem 1rem;
    font-family: 'Orbitron', sans-serif;
    font-size: 1rem;
    font-weight: 500;
    outline: none;
    transition: var(--ds-transition);
    min-width: 200px;
    text-align: center;
}

#ds-input:focus {
    border-color: var(--ds-secondary);
    box-shadow: 0 0 0 3px rgba(0, 247, 255, 0.3);
    transform: translateY(-2px);
}

#ds-input::placeholder {
    color: rgba(255, 255, 255, 0.5);
}

.ds-controls button {
    background: linear-gradient(135deg, var(--ds-primary) 0%, var(--ds-secondary) 100%);
    color: var(--ds-bg-dark);
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 10px;
    font-family: 'Orbitron', sans-serif;
    font-weight: 700;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--ds-transition);
    text-transform: uppercase;
    letter-spacing: 1px;
    position: relative;
    overflow: hidden;
}

.ds-controls button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.ds-controls button:hover::before {
    left: 100%;
}

.ds-controls button:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 10px 25px rgba(162, 89, 255, 0.4);
}

.ds-controls button:active {
    transform: translateY(-1px) scale(1.02);
}

/* Data Structure Specific Styles */

/* Stack Visualization */
.stack-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem;
}

.stack-item {
    background: linear-gradient(135deg, var(--ds-primary) 0%, var(--ds-secondary) 100%);
    color: var(--ds-bg-dark);
    padding: 1rem 2rem;
    border-radius: 10px;
    font-weight: 700;
    font-size: 1.2rem;
    min-width: 120px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(162, 89, 255, 0.3);
    transition: var(--ds-transition);
    animation: stack-item-enter 0.5s ease-out;
}

.stack-item.top {
    background: linear-gradient(135deg, var(--ds-accent) 0%, var(--ds-warning) 100%);
    transform: scale(1.1);
    box-shadow: 0 8px 25px rgba(255, 107, 107, 0.4);
    animation: stack-item-top 0.5s ease-out;
}

@keyframes stack-item-enter {
    from {
        opacity: 0;
        transform: translateY(-20px) scale(0.8);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

@keyframes stack-item-top {
    0% { transform: scale(1); }
    50% { transform: scale(1.2); }
    100% { transform: scale(1.1); }
}

/* Queue Visualization */
.queue-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    padding: 1rem;
    flex-wrap: wrap;
}

.queue-item {
    background: linear-gradient(135deg, var(--ds-secondary) 0%, var(--ds-primary) 100%);
    color: var(--ds-bg-dark);
    padding: 1rem 1.5rem;
    border-radius: 10px;
    font-weight: 700;
    font-size: 1.1rem;
    box-shadow: 0 4px 15px rgba(0, 247, 255, 0.3);
    transition: var(--ds-transition);
    animation: queue-item-enter 0.5s ease-out;
    position: relative;
}

.queue-item.front {
    background: linear-gradient(135deg, var(--ds-success) 0%, var(--ds-warning) 100%);
    transform: scale(1.1);
    box-shadow: 0 8px 25px rgba(81, 207, 102, 0.4);
    animation: queue-item-front 0.5s ease-out;
}

.queue-item::after {
    content: '→';
    position: absolute;
    right: -1.5rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--ds-secondary);
    font-size: 1.5rem;
    font-weight: bold;
}

.queue-item:last-child::after {
    display: none;
}

@keyframes queue-item-enter {
    from {
        opacity: 0;
        transform: translateX(-20px) scale(0.8);
    }
    to {
        opacity: 1;
        transform: translateX(0) scale(1);
    }
}

@keyframes queue-item-front {
    0% { transform: scale(1); }
    50% { transform: scale(1.2); }
    100% { transform: scale(1.1); }
}

/* Linked List Visualization */
.linkedlist-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    padding: 1rem;
    flex-wrap: wrap;
}

.list-node {
    background: linear-gradient(135deg, var(--ds-primary) 0%, var(--ds-secondary) 100%);
    color: var(--ds-bg-dark);
    padding: 1rem 1.5rem;
    border-radius: 50px;
    font-weight: 700;
    font-size: 1.1rem;
    box-shadow: 0 4px 15px rgba(162, 89, 255, 0.3);
    transition: var(--ds-transition);
    animation: list-node-enter 0.5s ease-out;
    position: relative;
}

.list-node::after {
    content: '→';
    position: absolute;
    right: -1.5rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--ds-secondary);
    font-size: 1.5rem;
    font-weight: bold;
    animation: arrow-pulse 2s ease-in-out infinite;
}

.list-node:last-child::after {
    content: 'null';
    font-size: 0.8rem;
    color: var(--ds-accent);
    font-style: italic;
}

@keyframes list-node-enter {
    from {
        opacity: 0;
        transform: scale(0.5) rotate(180deg);
    }
    to {
        opacity: 1;
        transform: scale(1) rotate(0deg);
    }
}

@keyframes arrow-pulse {
    0%, 100% { opacity: 0.7; }
    50% { opacity: 1; }
}

/* Binary Tree Visualization */
.tree-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 1rem;
}

.tree-level {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    margin: 0.5rem 0;
    position: relative;
}

.tree-node {
    background: linear-gradient(135deg, var(--ds-primary) 0%, var(--ds-secondary) 100%);
    color: var(--ds-bg-dark);
    padding: 1rem 1.5rem;
    border-radius: 50%;
    font-weight: 700;
    font-size: 1.1rem;
    box-shadow: 0 4px 15px rgba(162, 89, 255, 0.3);
    transition: var(--ds-transition);
    animation: tree-node-enter 0.5s ease-out;
    position: relative;
    min-width: 60px;
    min-height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.tree-children {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.tree-children::before {
    content: '';
    position: absolute;
    top: -1rem;
    left: 50%;
    width: 2px;
    height: 1rem;
    background: var(--ds-secondary);
    transform: translateX(-50%);
}

@keyframes tree-node-enter {
    from {
        opacity: 0;
        transform: scale(0) rotate(360deg);
    }
    to {
        opacity: 1;
        transform: scale(1) rotate(0deg);
    }
}

/* Hash Table Visualization */
.hashtable-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    padding: 1rem;
}

.hash-item {
    background: linear-gradient(135deg, var(--ds-bg-medium) 0%, var(--ds-bg-light) 100%);
    border: 2px solid var(--ds-border);
    border-radius: 10px;
    padding: 1rem;
    transition: var(--ds-transition);
    animation: hash-item-enter 0.5s ease-out;
}

.hash-item:hover {
    border-color: var(--ds-secondary);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 247, 255, 0.3);
}

.hash-item .key {
    color: var(--ds-primary);
    font-weight: 700;
    font-size: 1.1rem;
}

.hash-item .value {
    color: var(--ds-secondary);
    font-weight: 600;
    margin-left: 0.5rem;
}

@keyframes hash-item-enter {
    from {
        opacity: 0;
        transform: translateY(20px) scale(0.8);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

/* Empty State */
.empty-message {
    color: var(--ds-text-secondary);
    font-size: 1.2rem;
    font-style: italic;
    text-align: center;
    padding: 2rem;
    background: rgba(162, 89, 255, 0.1);
    border-radius: 10px;
    border: 2px dashed var(--ds-border);
    animation: empty-pulse 2s ease-in-out infinite;
}

@keyframes empty-pulse {
    0%, 100% { opacity: 0.6; }
    50% { opacity: 1; }
}

/* Message System */
.ds-message {
    position: fixed;
    top: 20px;
    right: 20px;
    background: linear-gradient(135deg, var(--ds-success) 0%, var(--ds-warning) 100%);
    color: var(--ds-bg-dark);
    padding: 1rem 1.5rem;
    border-radius: 10px;
    font-weight: 600;
    box-shadow: 0 8px 25px rgba(81, 207, 102, 0.4);
    z-index: 1000;
    animation: message-slide-in 0.3s ease-out;
    display: none;
}

@keyframes message-slide-in {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* Performance Metrics */
.ds-metrics {
    display: flex;
    justify-content: space-around;
    margin-top: 1.5rem;
    padding: 1rem;
    background: rgba(162, 89, 255, 0.1);
    border-radius: 10px;
    border: 1px solid var(--ds-border);
}

.metric {
    text-align: center;
}

.metric-label {
    color: var(--ds-secondary);
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.metric-value {
    color: var(--ds-text-primary);
    font-size: 1.2rem;
    font-weight: 700;
}

/* Responsive Design */
@media (max-width: 768px) {
    .data-structures-container {
        margin: 1rem;
        padding: 1.5rem;
    }
    
    .ds-header h2 {
        font-size: 2rem;
    }
    
    .ds-controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    #ds-input {
        min-width: auto;
    }
    
    .queue-container,
    .linkedlist-container {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .queue-item::after,
    .list-node::after {
        display: none;
    }
    
    .hashtable-container {
        grid-template-columns: 1fr;
    }
    
    .ds-metrics {
        flex-direction: column;
        gap: 1rem;
    }
}

@media (max-width: 480px) {
    .data-structures-container {
        padding: 1rem;
    }
    
    .ds-header h2 {
        font-size: 1.5rem;
    }
    
    .ds-controls button {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
    
    .stack-item,
    .queue-item,
    .list-node,
    .tree-node {
        padding: 0.75rem 1rem;
        font-size: 1rem;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Educational Content */
.ds-educational {
    margin-top: 2rem;
    padding: 1.5rem;
    background: rgba(162, 89, 255, 0.1);
    border-radius: 15px;
    border: 1px solid var(--ds-border);
}

.educational-content h4 {
    color: var(--ds-primary);
    font-size: 1.3rem;
    margin-bottom: 1rem;
    text-align: center;
}

.educational-content p {
    color: var(--ds-text-secondary);
    text-align: center;
    margin-bottom: 1.5rem;
    font-size: 1rem;
    line-height: 1.6;
}

.operations-info,
.use-cases {
    margin-bottom: 1.5rem;
}

.operations-info h5,
.use-cases h5 {
    color: var(--ds-secondary);
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
    text-align: center;
}

.operations-info ul,
.use-cases ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.operations-info li,
.use-cases li {
    color: var(--ds-text-primary);
    padding: 0.5rem 0;
    text-align: center;
    border-bottom: 1px solid rgba(162, 89, 255, 0.2);
}

.operations-info li:last-child,
.use-cases li:last-child {
    border-bottom: none;
}

.operations-info strong {
    color: var(--ds-accent);
}

/* Message Types */
.ds-message-success {
    background: linear-gradient(135deg, var(--ds-success) 0%, var(--ds-warning) 100%);
}

.ds-message-warning {
    background: linear-gradient(135deg, var(--ds-warning) 0%, var(--ds-accent) 100%);
}

.ds-message-error {
    background: linear-gradient(135deg, var(--ds-accent) 0%, #ff4757 100%);
}

.ds-message-info {
    background: linear-gradient(135deg, var(--ds-primary) 0%, var(--ds-secondary) 100%);
}

/* Button Specific Styles */
.btn-add {
    background: linear-gradient(135deg, var(--ds-success) 0%, var(--ds-warning) 100%) !important;
}

.btn-remove {
    background: linear-gradient(135deg, var(--ds-accent) 0%, #ff4757 100%) !important;
}

.btn-search {
    background: linear-gradient(135deg, var(--ds-secondary) 0%, var(--ds-primary) 100%) !important;
}

.btn-clear {
    background: linear-gradient(135deg, #6c757d 0%, #495057 100%) !important;
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
    .data-structures-container {
        border-width: 3px;
    }
    
    .ds-controls button {
        border: 2px solid var(--ds-text-primary);
    }
    
    #ds-input {
        border-width: 3px;
    }
}