/* ========================================
   CSS Variables & Design System
   ======================================== */
:root {
    /* Colors */
    --bg-primary: #0a0a0f;
    --bg-secondary: #111118;
    --bg-tertiary: #1a1a24;
    --bg-card: rgba(22, 22, 32, 0.95);
    
    --text-primary: #ffffff;
    --text-secondary: #9898a8;
    --text-muted: #5a5a6a;
    
    --accent-cyan: #00d4ff;
    --accent-magenta: #ff00d4;
    --accent-lime: #00ff88;
    --accent-orange: #ff9500;
    --accent-purple: #8b5cf6;
    
    --gradient-primary: linear-gradient(135deg, var(--accent-cyan), var(--accent-magenta));
    
    /* Spacing - compact */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 0.75rem;
    --space-lg: 1rem;
    --space-xl: 1.5rem;
    --space-2xl: 2rem;
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
}

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

html {
    scroll-behavior: smooth;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: var(--font-primary);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
    font-size: 14px;
    min-height: 100vh;
    overflow-x: hidden;
}

/* Custom Scrollbar */
::-webkit-scrollbar { width: 4px; height: 4px; }
::-webkit-scrollbar-track { background: var(--bg-secondary); }
::-webkit-scrollbar-thumb { background: var(--accent-cyan); border-radius: 2px; }

/* ========================================
   Utility Classes
   ======================================== */
.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.accent { color: var(--accent-cyan); }

/* ========================================
   Header
   ======================================== */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    padding: var(--space-md) 0;
    background: rgba(10, 10, 15, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1.1rem;
    font-weight: 700;
}

.logo-icon {
    color: var(--accent-cyan);
}

.nav {
    display: flex;
    gap: var(--space-lg);
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.nav-link:hover, .nav-link:active {
    color: var(--accent-cyan);
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
    padding: var(--space-2xl) 0;
    text-align: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-md);
    background: rgba(0, 212, 255, 0.1);
    border: 1px solid rgba(0, 212, 255, 0.2);
    border-radius: 100px;
    font-size: 0.75rem;
    color: var(--accent-cyan);
    margin-bottom: var(--space-lg);
}

.hero-title {
    font-size: 1.75rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--space-md);
}

.hero-subtitle {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
}

.hero-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    background: var(--gradient-primary);
    color: var(--bg-primary);
    text-decoration: none;
    border-radius: 100px;
    font-weight: 600;
    font-size: 0.875rem;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.hero-btn:active {
    transform: scale(0.98);
}

/* ========================================
   Programs Section
   ======================================== */
.programs {
    padding: var(--space-xl) 0 var(--space-2xl);
}

.section-header {
    margin-bottom: var(--space-lg);
}

.section-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-xs);
}

.section-subtitle {
    color: var(--text-muted);
    font-size: 0.8rem;
}

.programs-grid {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

/* Program Card - Compact List Style */
.program-card {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md);
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: background var(--transition-fast), border-color var(--transition-fast);
}

.program-card:active {
    background: rgba(0, 212, 255, 0.1);
    border-color: rgba(0, 212, 255, 0.3);
}

.card-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background: rgba(0, 212, 255, 0.1);
    border-radius: var(--radius-sm);
    color: var(--accent-cyan);
    flex-shrink: 0;
}

.card-content {
    flex: 1;
    min-width: 0;
}

.card-title {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 2px;
}

.card-desc {
    color: var(--text-muted);
    font-size: 0.75rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.card-arrow {
    color: var(--text-muted);
    flex-shrink: 0;
}

/* ========================================
   Modal - Full Screen Mobile
   ======================================== */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.modal.active {
    opacity: 1;
    visibility: visible;
}

.modal-backdrop {
    position: absolute;
    inset: 0;
    background: var(--bg-primary);
}

.modal-content {
    position: relative;
    display: flex;
    flex-direction: column;
    height: 100%;
    background: var(--bg-primary);
    transform: translateY(20px);
    transition: transform var(--transition-normal);
}

.modal.active .modal-content {
    transform: translateY(0);
}

.modal-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.modal-title-group {
    min-width: 0;
}

.modal-title {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 2px;
}

.modal-desc {
    color: var(--text-muted);
    font-size: 0.75rem;
}

.modal-close {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: rgba(255, 255, 255, 0.05);
    border: none;
    border-radius: 50%;
    color: var(--text-secondary);
    cursor: pointer;
    flex-shrink: 0;
}

.modal-close:active {
    background: rgba(255, 0, 100, 0.2);
}

/* Tab Navigation */
.tab-nav {
    display: flex;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-lg);
    background: var(--bg-secondary);
}

.tab-btn {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-md);
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    font-family: var(--font-primary);
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    transition: background var(--transition-fast), color var(--transition-fast);
}

.tab-btn.active {
    background: rgba(0, 212, 255, 0.15);
    color: var(--accent-cyan);
}

/* Tab Content */
.tab-content {
    display: none;
    flex: 1;
    overflow: auto;
}

.tab-content.active {
    display: flex;
    flex-direction: column;
}

/* Animation Area */
.animation-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-lg);
    min-height: 200px;
}

/* Variables Panel */
.variables-panel {
    padding: var(--space-md) var(--space-lg);
    background: var(--bg-secondary);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.panel-title {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-sm);
}

.variables-display {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.variable {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: var(--space-xs) var(--space-md);
    background: rgba(0, 0, 0, 0.3);
    border-radius: var(--radius-sm);
    min-width: 50px;
}

.variable-name {
    font-size: 0.65rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

.variable-value {
    font-size: 1rem;
    font-weight: 700;
    font-family: var(--font-mono);
    color: var(--accent-cyan);
    transition: color var(--transition-fast), transform var(--transition-fast);
}

.variable-value.updated {
    color: var(--accent-lime);
    transform: scale(1.15);
}

/* Variables Info Panel */
.variables-info {
    padding: var(--space-md);
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.var-item {
    display: grid;
    grid-template-columns: auto auto 1fr;
    gap: var(--space-md);
    align-items: start;
    padding: var(--space-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--accent-cyan);
}

.var-name {
    font-family: var(--font-mono);
    font-weight: 700;
    color: var(--accent-cyan);
    font-size: 0.9rem;
}

.var-type {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--accent-magenta);
    padding: 2px 8px;
    background: rgba(255, 0, 212, 0.1);
    border-radius: 4px;
}

.var-desc {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

@media (max-width: 500px) {
    .var-item {
        grid-template-columns: 1fr;
        gap: var(--space-xs);
    }
    
    .var-type {
        justify-self: start;
    }
}

/* Code Header & Copy Button */
.code-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-tertiary);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.code-header-title {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
}

.copy-btn {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-md);
    background: rgba(0, 212, 255, 0.1);
    border: 1px solid rgba(0, 212, 255, 0.2);
    border-radius: var(--radius-sm);
    color: var(--accent-cyan);
    font-family: var(--font-primary);
    font-size: 0.75rem;
    font-weight: 500;
    cursor: pointer;
    transition: background var(--transition-fast), border-color var(--transition-fast);
}

.copy-btn:hover, .copy-btn:active {
    background: rgba(0, 212, 255, 0.2);
    border-color: var(--accent-cyan);
}

.copy-btn.copied {
    background: rgba(0, 255, 136, 0.2);
    border-color: var(--accent-lime);
    color: var(--accent-lime);
}

/* Code Display */
.code-display {
    padding: var(--space-md);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    line-height: 1.7;
    overflow: auto;
    background: var(--bg-secondary);
    margin: 0;
    max-height: 60vh;
    overflow-x: auto;
    overflow-y: auto;
}

.code-display .line {
    display: block;
    padding: 1px 6px;
    border-radius: 3px;
    white-space: pre;
    min-width: max-content;
}

.code-display .line.active {
    background: rgba(0, 212, 255, 0.2);
    border-left: 2px solid var(--accent-cyan);
}

.code-display .keyword { color: var(--accent-magenta); }
.code-display .type { color: var(--accent-cyan); }
.code-display .number { color: var(--accent-orange); }
.code-display .method { color: var(--accent-lime); }
.code-display .string { color: var(--accent-orange); }
.code-display .comment { color: var(--text-muted); font-style: italic; }

/* Modal Controls */
.modal-controls {
    padding: var(--space-md) var(--space-lg);
    background: var(--bg-tertiary);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.input-group {
    display: flex;
    gap: var(--space-md);
    margin-bottom: var(--space-md);
}

.input-group:empty {
    display: none;
}

.input-group label {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.input-group input[type="number"] {
    width: 70px;
    padding: var(--space-xs) var(--space-sm);
    background: var(--bg-primary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 0.9rem;
}

.input-group input:focus {
    outline: none;
    border-color: var(--accent-cyan);
}

.control-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.control-buttons {
    display: flex;
    gap: var(--space-sm);
}

.control-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    color: var(--text-primary);
    cursor: pointer;
    transition: background var(--transition-fast);
}

.control-btn:active:not(:disabled) {
    background: rgba(0, 212, 255, 0.2);
}

.control-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.control-btn.primary {
    background: var(--accent-lime);
    border-color: var(--accent-lime);
    color: var(--bg-primary);
}

.control-btn.primary:active:not(:disabled) {
    background: #00cc6e;
}

.speed-control {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    color: var(--text-muted);
}

.speed-control input[type="range"] {
    width: 80px;
    accent-color: var(--accent-cyan);
}

#speedValue {
    font-size: 0.75rem;
    font-family: var(--font-mono);
    min-width: 30px;
}

/* ========================================
   Animation Elements
   ======================================== */
.anim-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 32px;
    height: 32px;
    padding: 0 var(--space-sm);
    background: var(--accent-cyan);
    color: var(--bg-primary);
    border-radius: var(--radius-sm);
    font-family: var(--font-mono);
    font-weight: 700;
    font-size: 0.9rem;
    animation: popIn 0.25s ease;
}

.anim-number.secondary { background: var(--accent-magenta); }
.anim-number.success { background: var(--accent-lime); }
.anim-number.warning { background: var(--accent-orange); }

@keyframes popIn {
    0% { transform: scale(0); opacity: 0; }
    70% { transform: scale(1.1); }
    100% { transform: scale(1); opacity: 1; }
}

.anim-row {
    display: flex;
    gap: 3px;
    animation: slideIn 0.2s ease;
}

@keyframes slideIn {
    from { opacity: 0; transform: translateX(-10px); }
    to { opacity: 1; transform: translateX(0); }
}

.anim-char {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 26px;
    height: 26px;
    background: var(--accent-purple);
    color: var(--text-primary);
    border-radius: 4px;
    font-family: var(--font-mono);
    font-weight: 600;
    font-size: 0.8rem;
    animation: popIn 0.15s ease;
}

.anim-operator {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    color: var(--accent-orange);
    font-weight: 600;
}

.result-display {
    padding: var(--space-md) var(--space-xl);
    background: linear-gradient(135deg, rgba(0, 255, 136, 0.15), rgba(0, 212, 255, 0.15));
    border: 1px solid var(--accent-lime);
    border-radius: var(--radius-md);
    font-family: var(--font-mono);
    font-size: 1rem;
    font-weight: 700;
    color: var(--accent-lime);
    text-align: center;
}

.result-display.error {
    background: linear-gradient(135deg, rgba(255, 0, 100, 0.15), rgba(255, 100, 0, 0.15));
    border-color: var(--accent-magenta);
    color: var(--accent-magenta);
}

/* ========================================
   About Section
   ======================================== */
.about {
    padding: var(--space-2xl) 0;
    text-align: center;
}

.about-text {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: var(--space-lg);
    line-height: 1.6;
}

.about-features {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.feature {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-card);
    border-radius: 100px;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.feature svg {
    color: var(--accent-cyan);
}

/* ========================================
   Footer
   ======================================== */
.footer {
    padding: var(--space-lg) 0;
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer p {
    color: var(--text-muted);
    font-size: 0.75rem;
}

/* ========================================
   Desktop Styles (600px+)
   ======================================== */
@media (min-width: 600px) {
    body {
        font-size: 15px;
    }
    
    .container {
        max-width: 800px;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .programs-grid {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space-md);
    }
    
    .program-card {
        padding: var(--space-lg);
    }
    
    .modal-content {
        margin: var(--space-xl);
        height: auto;
        max-height: calc(100vh - var(--space-xl) * 2);
        border-radius: var(--radius-lg);
        border: 1px solid rgba(255, 255, 255, 0.1);
    }
    
    .modal-backdrop {
        background: rgba(0, 0, 0, 0.8);
        backdrop-filter: blur(10px);
    }
    
    .animation-area {
        min-height: 250px;
    }
}

/* Large Desktop (900px+) */
@media (min-width: 900px) {
    .container {
        max-width: 1000px;
    }
    
    .programs-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .modal-content {
        max-width: 900px;
        margin: var(--space-2xl) auto;
    }
}