/* ===== CSS Variables & Design System ===== */
:root {
    /* Colors */
    --bg-primary: #0a0e27;
    --bg-secondary: #151932;
    --bg-tertiary: #1e2442;
    --bg-glass: rgba(30, 36, 66, 0.7);

    --producer-color: #00d4ff;
    --producer-glow: rgba(0, 212, 255, 0.3);
    --consumer-color: #ff6b35;
    --consumer-glow: rgba(255, 107, 53, 0.3);

    --success-color: #00ff88;
    --warning-color: #ffd700;
    --danger-color: #ff4757;
    --info-color: #5f27cd;

    --text-primary: #ffffff;
    --text-secondary: #b8c1ec;
    --text-muted: #6c7293;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-full: 50%;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 20px;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ===== Reset & Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, var(--bg-primary) 0%, #1a1f3a 100%);
    color: var(--text-primary);
    min-height: 100vh;
    padding: var(--spacing-md);
    overflow-x: hidden;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
}

/* ===== Header ===== */
.header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-lg);
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: var(--shadow-md);
}

.header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--producer-color), var(--consumer-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-sm);
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
    font-weight: 300;
}

/* ===== Control Panel ===== */
.control-panel {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.control-group {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
    font-family: inherit;
}

.btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn:active:not(:disabled) {
    transform: translateY(0);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background: linear-gradient(135deg, #00d4ff, #0099cc);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    box-shadow: 0 4px 16px var(--producer-glow);
}

.btn-secondary {
    background: linear-gradient(135deg, #ff6b35, #cc5529);
    color: white;
}

.btn-secondary:hover:not(:disabled) {
    box-shadow: 0 4px 16px var(--consumer-glow);
}

.btn-tertiary {
    background: linear-gradient(135deg, #5f27cd, #4a1fa8);
    color: white;
}

#speedControl {
    width: 150px;
    height: 6px;
    border-radius: 3px;
    background: var(--bg-tertiary);
    outline: none;
    appearance: none;
    -webkit-appearance: none;
}

#speedControl::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--producer-color);
    cursor: pointer;
    box-shadow: 0 0 10px var(--producer-glow);
}

#speedControl::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--producer-color);
    cursor: pointer;
    border: none;
}

#speedValue {
    min-width: 40px;
    font-weight: 600;
    color: var(--producer-color);
}

/* ===== Main Area ===== */
.main-area {
    display: grid;
    grid-template-columns: 1fr 2fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    align-items: center;
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
    font-weight: 500;
}

/* ===== Agent Cards ===== */
.agent-card {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: var(--spacing-lg);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.agent-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.agent-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-sm);
    animation: float 3s ease-in-out infinite;
}

.producer-icon {
    filter: drop-shadow(0 0 20px var(--producer-glow));
}

.consumer-icon {
    filter: drop-shadow(0 0 20px var(--consumer-glow));
}

@keyframes float {

    0%,
    100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(-10px);
    }
}

.agent-card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.agent-status {
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    background: var(--bg-tertiary);
    margin-bottom: var(--spacing-sm);
    font-size: 0.9rem;
    font-weight: 500;
}

.agent-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--success-color);
}

/* ===== Buffer Section ===== */
.buffer-section {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.buffer-container {
    position: relative;
    margin-bottom: var(--spacing-lg);
}

.buffer-ring {
    position: relative;
    width: 400px;
    height: 400px;
    margin: 0 auto;
}

.buffer-slot {
    position: absolute;
    width: 70px;
    height: 70px;
    border-radius: var(--radius-full);
    background: var(--bg-tertiary);
    border: 3px solid rgba(255, 255, 255, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    transition: background var(--transition-normal),
        border-color var(--transition-normal),
        box-shadow var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.buffer-slot.filled {
    background: linear-gradient(135deg, var(--producer-color), #0099cc);
    border-color: var(--producer-color);
    box-shadow: 0 0 20px var(--producer-glow);
    animation: pulse 1s ease-in-out;
}

@keyframes pulse {

    0%,
    100% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.1);
    }
}

.buffer-slot.consuming {
    animation: consume 0.5s ease-in-out;
}

@keyframes consume {
    0% {
        transform: scale(1);
    }

    50% {
        transform: scale(0.8);
        opacity: 0.5;
    }

    100% {
        transform: scale(1);
    }
}

/* Position slots in a circle - using margin for centering to avoid transform conflicts */
.buffer-slot[data-index="0"] {
    top: 0;
    left: 50%;
    margin-left: -35px;
}

.buffer-slot[data-index="1"] {
    top: 7%;
    right: 18%;
}

.buffer-slot[data-index="2"] {
    top: 50%;
    right: 0;
    margin-top: -35px;
}

.buffer-slot[data-index="3"] {
    bottom: 7%;
    right: 18%;
}

.buffer-slot[data-index="4"] {
    bottom: 0;
    left: 50%;
    margin-left: -35px;
}

.buffer-slot[data-index="5"] {
    bottom: 7%;
    left: 18%;
}

.buffer-slot[data-index="6"] {
    top: 50%;
    left: 0;
    margin-top: -35px;
}

.buffer-slot[data-index="7"] {
    top: 7%;
    left: 18%;
}

.buffer-pointers {
    display: flex;
    justify-content: space-around;
    margin-top: var(--spacing-md);
}

.pointer {
    text-align: center;
    font-weight: 600;
    font-size: 0.9rem;
}

.head-pointer {
    color: var(--producer-color);
}

.tail-pointer {
    color: var(--consumer-color);
}

.pointer-arrow {
    font-size: 1.5rem;
    animation: bounce 1s ease-in-out infinite;
}

@keyframes bounce {

    0%,
    100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(-5px);
    }
}

/* ===== Critical Section ===== */
.critical-section {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    border: 2px solid transparent;
    transition: all var(--transition-normal);
}

.critical-section.locked {
    border-color: var(--danger-color);
    background: rgba(255, 71, 87, 0.1);
    animation: glow 1s ease-in-out infinite;
}

@keyframes glow {

    0%,
    100% {
        box-shadow: 0 0 10px rgba(255, 71, 87, 0.3);
    }

    50% {
        box-shadow: 0 0 20px rgba(255, 71, 87, 0.6);
    }
}

.lock-icon {
    font-size: 1.5rem;
}

/* ===== Semaphores Section ===== */
.semaphores-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.semaphore-card {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.semaphore-card h3 {
    text-align: center;
    margin-bottom: var(--spacing-md);
    font-size: 1.3rem;
}

.semaphore-gauge {
    width: 100%;
    height: 40px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    overflow: hidden;
    margin-bottom: var(--spacing-sm);
    box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.3);
}

.gauge-fill {
    height: 100%;
    transition: width var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
}

.empty-gauge {
    background: linear-gradient(90deg, var(--producer-color), #0099cc);
    box-shadow: 0 0 20px var(--producer-glow);
}

.full-gauge {
    background: linear-gradient(90deg, var(--consumer-color), #cc5529);
    box-shadow: 0 0 20px var(--consumer-glow);
}

.semaphore-value {
    text-align: center;
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
    color: var(--success-color);
}

.semaphore-desc {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ===== Bottom Section ===== */
.bottom-section {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-lg);
}

.stats-panel,
.log-panel {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.stats-panel h3,
.log-panel h3 {
    margin-bottom: var(--spacing-md);
    font-size: 1.3rem;
}

.stat-item {
    display: flex;
    justify-content: space-between;
    padding: var(--spacing-sm);
    margin-bottom: var(--spacing-xs);
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
}

.stat-label {
    color: var(--text-secondary);
}

.stat-value {
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--success-color);
}

.log-container {
    max-height: 300px;
    overflow-y: auto;
    padding: var(--spacing-sm);
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
}

.log-container::-webkit-scrollbar {
    width: 8px;
}

.log-container::-webkit-scrollbar-track {
    background: var(--bg-secondary);
    border-radius: 4px;
}

.log-container::-webkit-scrollbar-thumb {
    background: var(--producer-color);
    border-radius: 4px;
}

.log-entry {
    padding: 0.5rem;
    margin-bottom: 0.5rem;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    border-left: 3px solid;
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.log-producer {
    background: rgba(0, 212, 255, 0.1);
    border-color: var(--producer-color);
}

.log-consumer {
    background: rgba(255, 107, 53, 0.1);
    border-color: var(--consumer-color);
}

.log-info {
    background: rgba(95, 39, 205, 0.1);
    border-color: var(--info-color);
}

.log-warning {
    background: rgba(255, 215, 0, 0.1);
    border-color: var(--warning-color);
}

/* ===== Explanation Section ===== */
.explanation-section {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-lg);
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: var(--shadow-md);
}

.explanation-section h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: var(--spacing-lg);
    background: linear-gradient(135deg, var(--producer-color), var(--consumer-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.explanation-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
}

.explanation-card {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.explanation-card.full-width {
    grid-column: 1 / -1;
}

.explanation-card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.explanation-card h4 {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.explanation-card p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-sm);
}

.explanation-card ul {
    margin-left: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
}

.explanation-card li {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-xs);
}

.explanation-card code {
    background: var(--bg-tertiary);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    color: var(--producer-color);
    font-size: 0.9em;
}

.highlight {
    background: rgba(255, 215, 0, 0.1);
    border-left: 3px solid var(--warning-color);
    padding: var(--spacing-sm);
    border-radius: var(--radius-sm);
    margin-top: var(--spacing-sm);
}

.invariant {
    background: rgba(0, 255, 136, 0.1);
    border-left: 3px solid var(--success-color);
    padding: var(--spacing-sm);
    border-radius: var(--radius-sm);
    margin-top: var(--spacing-sm);
}

.semaphore-explanation {
    margin: var(--spacing-md) 0;
}

.sem-item {
    background: var(--bg-tertiary);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    margin-bottom: var(--spacing-sm);
}

.sem-name {
    display: inline-block;
    background: linear-gradient(135deg, var(--producer-color), var(--consumer-color));
    color: white;
    padding: 0.3rem 0.8rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.algorithm-steps {
    margin-top: var(--spacing-md);
}

.step {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    background: var(--bg-tertiary);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    transition: all var(--transition-normal);
}

.step:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-sm);
}

.step-number {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, var(--producer-color), var(--consumer-color));
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
}

.step-content {
    flex: 1;
}

.step-content strong {
    display: block;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
    font-size: 1.1rem;
}

.step-content code {
    display: block;
    margin: var(--spacing-xs) 0;
}

.step-content p {
    margin-bottom: 0;
    font-size: 0.9rem;
}

.properties-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.property {
    background: var(--bg-tertiary);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    text-align: center;
    transition: all var(--transition-normal);
}

.property:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.property-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.property h4 {
    margin-bottom: var(--spacing-sm);
}

.property p {
    margin-bottom: 0;
    font-size: 0.9rem;
}

.execution-example {
    margin-top: var(--spacing-md);
    overflow-x: auto;
}

.execution-example table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.execution-example th,
.execution-example td {
    padding: var(--spacing-sm);
    text-align: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.execution-example th {
    background: var(--bg-primary);
    color: var(--text-primary);
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.9rem;
}

.execution-example td {
    color: var(--text-secondary);
}

.execution-example tbody tr:hover {
    background: rgba(255, 255, 255, 0.02);
}

.execution-example .producer-row {
    background: rgba(0, 212, 255, 0.05);
}

.execution-example .consumer-row {
    background: rgba(255, 107, 53, 0.05);
}

.note {
    margin-top: var(--spacing-md);
    padding: var(--spacing-sm);
    background: rgba(95, 39, 205, 0.1);
    border-left: 3px solid var(--info-color);
    border-radius: var(--radius-sm);
}

/* ===== Responsive Design ===== */
@media (max-width: 1200px) {
    .main-area {
        grid-template-columns: 1fr;
    }

    .buffer-ring {
        width: 350px;
        height: 350px;
    }

    .buffer-slot {
        width: 60px;
        height: 60px;
        font-size: 1.2rem;
    }

    .explanation-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .header h1 {
        font-size: 1.8rem;
    }

    .semaphores-section,
    .bottom-section {
        grid-template-columns: 1fr;
    }

    .control-panel {
        flex-direction: column;
    }

    .buffer-ring {
        width: 300px;
        height: 300px;
    }

    .buffer-slot {
        width: 50px;
        height: 50px;
        font-size: 1rem;
    }

    .explanation-section h2 {
        font-size: 1.5rem;
    }

    .properties-grid {
        grid-template-columns: 1fr;
    }

    .execution-example {
        font-size: 0.85rem;
    }
}