/* ========================================
   SPATIAL INVERSE — Design System
   ======================================== */

/* --- CSS Custom Properties --- */
:root {
    /* Colors — Neon Dark Theme */
    --bg-primary: #0a0a1a;
    --bg-secondary: #111128;
    --bg-tertiary: #1a1a3e;
    --bg-card: rgba(20, 20, 50, 0.7);

    --text-primary: #e8e8ff;
    --text-secondary: #9898cc;
    --text-muted: #5a5a8a;

    --neon-cyan: #00f0ff;
    --neon-magenta: #ff00aa;
    --neon-purple: #b44aff;
    --neon-green: #00ff88;
    --neon-yellow: #ffee00;
    --neon-orange: #ff8800;
    --neon-red: #ff3355;

    --glow-cyan: 0 0 20px rgba(0, 240, 255, 0.5);
    --glow-magenta: 0 0 20px rgba(255, 0, 170, 0.5);
    --glow-purple: 0 0 20px rgba(180, 74, 255, 0.5);
    --glow-green: 0 0 20px rgba(0, 255, 136, 0.5);

    /* Glass */
    --glass-bg: rgba(20, 20, 60, 0.6);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-blur: 16px;

    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;

    /* Radius */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --radius-full: 999px;

    /* Typography */
    --font-display: 'Orbitron', sans-serif;
    --font-body: 'Inter', sans-serif;
    --fs-xs: clamp(0.55rem, 1.5vw, 0.7rem);
    --fs-sm: clamp(0.65rem, 1.8vw, 0.8rem);
    --fs-base: clamp(0.8rem, 2.2vw, 1rem);
    --fs-md: clamp(0.9rem, 2.5vw, 1.15rem);
    --fs-lg: clamp(1rem, 3vw, 1.4rem);
    --fs-xl: clamp(1.3rem, 4vw, 2rem);
    --fs-2xl: clamp(1.6rem, 5.5vw, 2.8rem);
    --fs-3xl: clamp(2rem, 7vw, 4rem);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 300ms ease;
    --transition-slow: 500ms ease;

    /* Z-Index */
    --z-bg: 0;
    --z-content: 10;
    --z-hud: 50;
    --z-toolbar: 60;
    --z-modal-overlay: 100;
    --z-modal: 110;
}

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

html,
body {
    width: 100%;
    height: 100%;
    overflow: hidden;
    font-family: var(--font-body);
    font-size: clamp(13px, 2.5vw, 16px);
    color: var(--text-primary);
    background: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    user-select: none;
    -webkit-user-select: none;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

/* --- Utility Classes --- */
.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
}

/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    border: none;
    border-radius: var(--radius-full);
    font-family: var(--font-display);
    font-size: var(--fs-sm);
    font-weight: 600;
    letter-spacing: 0.1em;
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
    text-transform: uppercase;
}

.btn::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.1), transparent);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.btn:hover::after {
    opacity: 1;
}

.btn:active {
    transform: scale(0.96);
}

.btn-primary {
    background: linear-gradient(135deg, var(--neon-cyan), var(--neon-purple));
    color: #fff;
    box-shadow: 0 4px 20px rgba(0, 240, 255, 0.3);
}

.btn-primary:hover {
    box-shadow: 0 6px 30px rgba(0, 240, 255, 0.5);
    transform: translateY(-2px);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.06);
    color: var(--text-primary);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.12);
    border-color: rgba(255, 255, 255, 0.2);
}

.btn-danger {
    background: rgba(255, 51, 85, 0.15);
    color: var(--neon-red);
    border: 1px solid rgba(255, 51, 85, 0.3);
    font-family: var(--font-body);
    font-size: var(--fs-sm);
    width: 100%;
}

.btn-danger:hover {
    background: rgba(255, 51, 85, 0.25);
}

.btn-glow {
    animation: pulseGlow 2s ease-in-out infinite;
}

.btn-icon-only {
    width: 44px;
    height: 44px;
    padding: 0;
    border-radius: 50%;
    font-size: var(--fs-lg);
}

.btn-back {
    background: rgba(255, 255, 255, 0.06);
    color: var(--text-primary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    font-family: var(--font-body);
}

.btn-back:hover {
    background: rgba(255, 255, 255, 0.12);
}

.btn-sm {
    width: 36px;
    height: 36px;
    font-size: var(--fs-base);
}

/* --- Toggle Switch --- */
.toggle {
    position: relative;
    display: inline-block;
    width: 48px;
    height: 26px;
}

.toggle input {
    opacity: 0;
    width: 0;
    height: 0;
}

.toggle-slider {
    position: absolute;
    cursor: pointer;
    inset: 0;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-full);
    transition: var(--transition-normal);
}

.toggle-slider::before {
    content: '';
    position: absolute;
    height: 20px;
    width: 20px;
    left: 3px;
    bottom: 3px;
    background: var(--text-primary);
    border-radius: 50%;
    transition: var(--transition-normal);
}

.toggle input:checked+.toggle-slider {
    background: var(--neon-cyan);
    box-shadow: var(--glow-cyan);
}

.toggle input:checked+.toggle-slider::before {
    transform: translateX(22px);
}

/* --- Screen Base --- */
.screen {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-slow);
    z-index: var(--z-content);
}

.screen.active {
    opacity: 1;
    pointer-events: auto;
}

/* --- Modal --- */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal-overlay);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-normal);
    backdrop-filter: blur(4px);
}

.modal-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.modal {
    width: 90%;
    max-width: 420px;
    padding: var(--space-xl) var(--space-lg);
    text-align: center;
    transform: scale(0.9) translateY(20px);
    transition: transform var(--transition-normal);
}

.modal-overlay.active .modal {
    transform: scale(1) translateY(0);
}

.modal-title {
    font-family: var(--font-display);
    font-size: var(--fs-xl);
    background: linear-gradient(135deg, var(--neon-cyan), var(--neon-green));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--space-lg);
}

.modal-title-lose {
    background: linear-gradient(135deg, var(--neon-orange), var(--neon-red));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.modal-subtitle {
    color: var(--text-secondary);
    font-size: var(--fs-sm);
    margin-bottom: var(--space-xl);
    line-height: 1.5;
}

.modal-buttons {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    margin-top: var(--space-lg);
}

.modal-stats {
    margin: var(--space-lg) 0;
}

.stat-row {
    display: flex;
    justify-content: space-between;
    padding: var(--space-sm) var(--space-md);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.stat-label {
    color: var(--text-secondary);
    font-size: var(--fs-sm);
}

.stat-value {
    color: var(--neon-cyan);
    font-family: var(--font-display);
    font-size: var(--fs-sm);
}

/* --- Stars --- */
.stars-display {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
    margin: var(--space-lg) 0;
}

.star {
    font-size: 2rem;
    color: var(--text-muted);
    transition: all 0.5s ease;
}

.star.earned {
    color: var(--neon-yellow);
    text-shadow: 0 0 15px rgba(255, 238, 0, 0.6);
}

.star-lg {
    font-size: 3rem;
}

/* --- Settings --- */
.settings-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    margin: var(--space-lg) 0;
}

.setting-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-md);
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.03);
}

.setting-row.danger {
    margin-top: var(--space-md);
    background: transparent;
}

.setting-label {
    font-size: var(--fs-sm);
    color: var(--text-secondary);
}

/* --- Scrollbar --- */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.15);
    border-radius: 3px;
}