:root {
    /* Fonts */
    --font-ui: 'Space Grotesk', sans-serif;
    --font-code: 'JetBrains Mono', monospace;
    
    /* Deep Dark Tech Theme */
    --bg-dark: #0f172a;
    --bg-gradient-1: #1e1b4b;
    --bg-gradient-2: #312e81;
    
    /* Glass Surface */
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-highlight: rgba(255, 255, 255, 0.03);
    
    /* Text Colors */
    --text-main: #e2e8f0;
    --text-muted: #64748b;
    --text-ghost: #475569;
    
    /* Accents */
    --accent-primary: #818cf8; /* Indigo-400 */
    --accent-glow: rgba(129, 140, 248, 0.5);
    --accent-secondary: #2dd4bf; /* Teal-400 */
    
    /* Functional */
    --color-success: #34d399;
    --color-error: #f87171;
    
    /* Effects */
    --shadow-glass: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
    --radius-lg: 24px;
    --radius-md: 12px;
    --radius-sm: 6px;
}

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

body {
    font-family: var(--font-ui);
    background-color: var(--bg-dark);
    color: var(--text-main);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    overflow: hidden; /* Prevent scroll during animations */
}

/* Animated Background */
.background-glow {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: radial-gradient(circle at 0% 0%, var(--bg-gradient-1), transparent 50%),
                radial-gradient(circle at 100% 100%, var(--bg-gradient-2), transparent 50%);
    z-index: -1;
    animation: pulse-bg 10s ease-in-out infinite alternate;
}

@keyframes pulse-bg {
    0% { opacity: 0.5; transform: scale(1); }
    100% { opacity: 0.8; transform: scale(1.1); }
}

/* Glass Container */
.container {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    padding: 3rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-glass);
    width: 90%;
    max-width: 960px;
    margin: 2rem;
    position: relative;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--glass-border), transparent);
}

header {
    text-align: center;
    margin-bottom: 3rem;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.05em;
    color: var(--text-main);
}

header h1 .accent {
    color: var(--accent-primary);
    text-shadow: 0 0 20px var(--accent-glow);
}

.icon-btn {
    position: absolute;
    right: 0;
    background: transparent;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 0.5rem;
    transition: color 0.2s, transform 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-btn:hover {
    color: var(--text-main);
    transform: rotate(45deg);
}

/* Stats HUD */
.stats {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 1rem;
    margin-bottom: 2.5rem;
    padding: 1rem;
    background: rgba(15, 23, 42, 0.3);
    border-radius: var(--radius-md);
    border: 1px solid var(--glass-border);
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 0.5rem;
    transition: transform 0.2s;
}

.stat-item.primary {
    background: var(--glass-highlight);
    border-radius: var(--radius-sm);
    border: 1px solid rgba(255,255,255,0.05);
}

.stat-item.highlight .value {
    color: var(--accent-secondary);
}

.stat-item .label {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.stat-item .value {
    font-family: var(--font-code);
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-main);
    line-height: 1;
}

.stat-item .unit {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-left: 2px;
    font-weight: 400;
}

/* Controls & Toggle */
.controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    gap: 1rem;
}

.control-group {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.category-select {
    background: rgba(30, 41, 59, 0.9);
    color: #ffffff;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    padding: 0.5rem 1rem;
    font-family: var(--font-ui);
    font-size: 0.9rem;
    cursor: pointer;
    outline: none;
    transition: border-color 0.2s, background 0.2s;
}

.category-select option {
    background-color: var(--bg-dark);
    color: var(--text-main);
    padding: 10px;
}

.category-select:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--text-muted);
}

.category-select:focus {
    border-color: var(--accent-primary);
}

.toggle-label {
    font-size: 0.85rem;
    color: var(--text-muted);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transition: color 0.2s;
    font-weight: 500;
}

.toggle-label:hover {
    color: var(--text-main);
}

.toggle-label input {
    display: none;
}

.toggle-custom {
    width: 36px;
    height: 20px;
    background: rgba(255,255,255,0.1);
    border-radius: 20px;
    position: relative;
    transition: background 0.3s;
}

.toggle-custom::after {
    content: '';
    position: absolute;
    top: 2px;
    left: 2px;
    width: 16px;
    height: 16px;
    background: var(--text-muted);
    border-radius: 50%;
    transition: transform 0.3s, background 0.3s;
}

input:checked + .toggle-custom {
    background: var(--accent-primary);
}

input:checked + .toggle-custom::after {
    transform: translateX(16px);
    background: #fff;
}

/* Badges */
.mode-badges {
    display: flex;
    gap: 0.5rem;
}

.badge {
    font-size: 0.75rem;
    background: rgba(255, 255, 255, 0.1);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    color: var(--text-muted);
    font-weight: 600;
}

.badge.hidden {
    display: none;
}

/* Typing Area */
.typing-container {
    position: relative;
    margin-bottom: 2.5rem;
}

.quote-display {
    font-family: var(--font-code);
    font-size: 1.5rem;
    line-height: 1.7;
    min-height: 120px;
    color: var(--text-ghost);
    white-space: pre-wrap;
    word-break: break-word;
    user-select: none;
    transition: filter 0.3s ease;
}

.quote-display.blurred {
    filter: blur(5px);
}

/* Text Effects */
.correct {
    color: var(--text-main);
    text-shadow: 0 0 10px rgba(255, 255, 255, 0.2);
}

.incorrect {
    color: var(--color-error);
    text-decoration: underline;
    text-decoration-style: wavy;
    text-decoration-color: var(--color-error);
    text-shadow: 0 0 10px rgba(248, 113, 113, 0.3);
}

.current {
    color: var(--accent-secondary);
    background: rgba(45, 212, 191, 0.15);
    border-radius: 2px;
    position: relative;
}

/* Blinking Caret */
.current::before {
    content: '';
    position: absolute;
    left: 0;
    bottom: -2px;
    width: 100%;
    height: 2px;
    background-color: var(--accent-secondary);
    box-shadow: 0 0 8px var(--accent-secondary);
    animation: blink 1s step-end infinite;
}

@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
}

/* Hidden Input (Overlay) */
.typing-input {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: default;
    z-index: 10; /* Above display to capture clicks */
    resize: none;
}

/* Ghost Cursor */
.ghost-cursor {
    position: absolute;
    top: 0;
    left: 0;
    width: 2px;
    height: 1.5rem;
    background-color: rgba(255, 255, 255, 0.3);
    border: 1px dashed rgba(255, 255, 255, 0.5);
    pointer-events: none;
    opacity: 0;
    transition: transform 0.1s linear; /* Smooth catch-up */
    z-index: 5;
}

/* Button */
.reset-btn {
    background: transparent;
    color: var(--text-muted);
    border: 1px solid var(--glass-border);
    padding: 0.75rem 2rem;
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin: 0 auto;
    font-family: var(--font-ui);
}

.reset-btn:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-main);
    border-color: var(--text-muted);
    transform: translateY(-1px);
}

.reset-btn svg {
    transition: transform 0.4s ease;
}

.reset-btn:hover svg {
    transform: rotate(180deg);
}

footer {
    margin-top: 2rem;
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-ghost);
    text-transform: uppercase;
    letter-spacing: 0.2em;
}

/* Responsive */
@media (max-width: 640px) {
    .container {
        padding: 1.5rem;
        margin: 1rem;
    }
    
    .stats {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .stats .stat-item:nth-child(4),
    .stats .stat-item:nth-child(5) {
        grid-column: span 1; /* adjust if needed */
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .controls {
        flex-direction: column;
        gap: 1rem;
        align-items: stretch;
    }
    
    .control-group {
        justify-content: space-between;
    }
}

/* Focus Mode Effects */
.container.focus-mode header,
.container.focus-mode .stats,
.container.focus-mode .controls,
.container.focus-mode footer {
    opacity: 0.3;
    transition: opacity 0.5s ease;
    pointer-events: none; /* Prevent clicking distracted elements */
}

.container.focus-mode .typing-container {
    transform: scale(1.02);
    transition: transform 0.5s ease;
}

/* Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(8px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
}

.modal-overlay.show {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    padding: 2.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-glass);
    text-align: center;
    max-width: 400px;
    width: 90%;
    transform: scale(0.9);
    transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.modal-overlay.show .modal-content {
    transform: scale(1);
}

.modal-content h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-main);
}

.modal-stats {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
}

.modal-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.modal-stat .label {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.modal-stat .value {
    font-family: var(--font-code);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent-secondary);
}

.modal-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.action-btn {
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    font-family: var(--font-ui);
    border: none;
}

.action-btn.primary {
    background: var(--accent-primary);
    color: white;
}

.action-btn.primary:hover {
    background: var(--accent-glow);
    box-shadow: 0 0 15px var(--accent-glow);
}

.action-btn.secondary {
    background: transparent;
    border: 1px solid var(--text-muted);
    color: var(--text-main);
}

.action-btn.secondary:hover {
    border-color: var(--text-main);
    background: rgba(255, 255, 255, 0.05);
}

/* Settings Modal Specifics */
.settings-content {
    text-align: left;
    width: 100%;
    max-width: 500px;
}

.setting-group {
    margin-bottom: 2rem;
}

.setting-group label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
}

.pill-selector {
    display: flex;
    background: rgba(0, 0, 0, 0.2);
    padding: 4px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--glass-border);
}

.pill {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-muted);
    padding: 0.5rem 1rem;
    border-radius: 4px;
    cursor: pointer;
    font-family: var(--font-ui);
    font-size: 0.9rem;
    transition: all 0.2s;
}

.pill:hover {
    color: var(--text-main);
}

.pill.active {
    background: var(--glass-highlight);
    color: var(--text-main);
    font-weight: 600;
    box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

.toggles-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.hidden {
    display: none !important;
}

/* Chart Container */
.chart-container {
    margin: 2rem 0;
    padding: 1rem;
    background: rgba(0, 0, 0, 0.1);
    border-radius: var(--radius-md);
}

.chart-container h3 {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
    text-transform: uppercase;
}

#progress-chart {
    width: 100%;
    height: 100px;
}

#progress-chart polyline {
    fill: none;
    stroke: var(--accent-secondary);
    stroke-width: 2;
    vector-effect: non-scaling-stroke;
}

#progress-chart circle {
    fill: var(--bg-dark);
    stroke: var(--accent-secondary);
    stroke-width: 2;
    r: 4;
}