/* ==========================================
   SLIDING PUZZLE - PREMIUM CSS
   ========================================== */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700;800;900&family=Orbitron:wght@400;500;600;700;800;900&display=swap');

/* ---------- CSS Variables / Design Tokens ---------- */
:root {
    /* Colors */
    --bg-primary: #0a0a1a;
    --bg-secondary: #12122a;
    --bg-glass: rgba(255, 255, 255, 0.06);
    --bg-glass-hover: rgba(255, 255, 255, 0.1);
    --bg-glass-strong: rgba(255, 255, 255, 0.12);
    --border-glass: rgba(255, 255, 255, 0.12);
    --border-glass-hover: rgba(255, 255, 255, 0.2);

    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-muted: rgba(255, 255, 255, 0.4);

    --accent-primary: #a855f7;
    --accent-secondary: #6366f1;
    --accent-gold: #fbbf24;
    --accent-emerald: #10b981;
    --accent-rose: #f43f5e;
    --accent-cyan: #06b6d4;

    --glow-primary: rgba(168, 85, 247, 0.4);
    --glow-secondary: rgba(99, 102, 241, 0.4);
    --glow-gold: rgba(251, 191, 36, 0.4);

    /* Tile Colors per theme */
    --tile-bg: linear-gradient(135deg, #6366f1, #a855f7);
    --tile-shadow: rgba(99, 102, 241, 0.5);
    --tile-text: #ffffff;

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

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-2xl: 24px;
    --radius-full: 50%;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);

    /* Fonts */
    --font-primary: 'Outfit', sans-serif;
    --font-display: 'Orbitron', sans-serif;

    /* Z-indexes */
    --z-bg: 0;
    --z-particles: 1;
    --z-content: 10;
    --z-hud: 20;
    --z-modal: 50;
    --z-overlay: 100;
    --z-toast: 200;
}

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

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-primary);
    background: var(--bg-primary);
    color: var(--text-primary);
    overflow: hidden;
    width: 100vw;
    height: 100vh;
    height: 100dvh;
    user-select: none;
    -webkit-user-select: none;
    -webkit-tap-highlight-color: transparent;
}

button {
    font-family: var(--font-primary);
    cursor: pointer;
    border: none;
    outline: none;
    background: none;
    color: inherit;
    font-size: inherit;
}

/* ---------- Background System ---------- */
#game-background {
    position: fixed;
    inset: 0;
    z-index: var(--z-bg);
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    transition: opacity 1s ease;
}

#game-background::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at center, transparent 0%, rgba(0,0,0,0.4) 100%);
}

/* Theme backgrounds */
.theme-cosmic #game-background {
    background-image: url('../assets/images/bg-cosmic.png');
}
.theme-ocean #game-background {
    background-image: url('../assets/images/bg-ocean.png');
}
.theme-forest #game-background {
    background-image: url('../assets/images/bg-forest.png');
}
.theme-volcano #game-background {
    background-color: #1a0505;
    background-image:
        radial-gradient(ellipse at 30% 80%, rgba(255, 60, 0, 0.15) 0%, transparent 60%),
        radial-gradient(ellipse at 70% 20%, rgba(255, 100, 0, 0.1) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(80, 0, 0, 0.3) 0%, transparent 80%);
}
.theme-neon #game-background {
    background-color: #0a001a;
    background-image:
        radial-gradient(ellipse at 20% 80%, rgba(255, 0, 128, 0.12) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(0, 255, 255, 0.12) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(128, 0, 255, 0.08) 0%, transparent 70%);
}
.theme-crystal #game-background {
    background-color: #050a1a;
    background-image:
        radial-gradient(ellipse at 30% 30%, rgba(100, 200, 255, 0.1) 0%, transparent 50%),
        radial-gradient(ellipse at 70% 70%, rgba(200, 220, 255, 0.08) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(150, 180, 255, 0.05) 0%, transparent 80%);
}
.theme-galaxy #game-background {
    background-color: #0a0020;
    background-image:
        radial-gradient(ellipse at 25% 25%, rgba(168, 85, 247, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 75% 75%, rgba(251, 191, 36, 0.1) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(99, 102, 241, 0.08) 0%, transparent 70%);
}
.theme-inferno #game-background {
    background-color: #150000;
    background-image:
        radial-gradient(ellipse at 50% 90%, rgba(255, 0, 0, 0.2) 0%, transparent 60%),
        radial-gradient(ellipse at 30% 30%, rgba(255, 80, 0, 0.1) 0%, transparent 50%),
        radial-gradient(ellipse at 70% 50%, rgba(200, 0, 0, 0.1) 0%, transparent 50%);
}
.theme-ultimate #game-background {
    background-color: #0a0a0a;
    background-image:
        radial-gradient(ellipse at 20% 50%, rgba(255, 0, 100, 0.12) 0%, transparent 40%),
        radial-gradient(ellipse at 80% 50%, rgba(0, 200, 255, 0.12) 0%, transparent 40%),
        radial-gradient(ellipse at 50% 20%, rgba(168, 85, 247, 0.1) 0%, transparent 40%),
        radial-gradient(ellipse at 50% 80%, rgba(251, 191, 36, 0.1) 0%, transparent 40%);
    animation: ultimateBgShift 10s ease infinite;
}

@keyframes ultimateBgShift {
    0%, 100% { filter: hue-rotate(0deg); }
    50% { filter: hue-rotate(60deg); }
}

/* ---------- Particle Canvas ---------- */
#particle-canvas {
    position: fixed;
    inset: 0;
    z-index: var(--z-particles);
    pointer-events: none;
}

/* ---------- Screen System ---------- */
.screen {
    position: fixed;
    inset: 0;
    z-index: var(--z-content);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.5s ease, visibility 0.5s ease;
    padding: var(--gap-md);
}

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

/* ---------- Glass Panel ---------- */
.glass-panel {
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-xl);
    padding: var(--gap-xl);
    position: relative;
    overflow: hidden;
}

.glass-panel::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
}

.glass-panel-strong {
    background: var(--bg-glass-strong);
    border-color: var(--border-glass-hover);
}

/* ---------- Main Menu ---------- */
#menu-screen {
    gap: var(--gap-xl);
}

.menu-icon {
    width: 120px;
    height: 120px;
    border-radius: var(--radius-2xl);
    object-fit: cover;
    box-shadow: 0 20px 60px rgba(168, 85, 247, 0.3), 0 0 80px rgba(168, 85, 247, 0.1);
    animation: iconFloat 3s ease-in-out infinite;
    border: 2px solid rgba(168, 85, 247, 0.3);
}

@keyframes iconFloat {
    0%, 100% { transform: translateY(0) scale(1); }
    50% { transform: translateY(-10px) scale(1.02); }
}

.menu-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 6vw, 3.5rem);
    font-weight: 800;
    text-align: center;
    background: linear-gradient(135deg, #a855f7, #6366f1, #06b6d4);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: none;
    letter-spacing: 2px;
    animation: titleGlow 3s ease-in-out infinite alternate;
}

@keyframes titleGlow {
    0% { filter: brightness(1) drop-shadow(0 0 10px rgba(168, 85, 247, 0.3)); }
    100% { filter: brightness(1.1) drop-shadow(0 0 20px rgba(168, 85, 247, 0.5)); }
}

.menu-subtitle {
    font-size: clamp(0.9rem, 2.5vw, 1.1rem);
    color: var(--text-secondary);
    text-align: center;
    letter-spacing: 4px;
    text-transform: uppercase;
    font-weight: 300;
}

.menu-buttons {
    display: flex;
    flex-direction: column;
    gap: var(--gap-md);
    width: 100%;
    max-width: 320px;
}

/* ---------- Buttons ---------- */
.btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--gap-sm);
    padding: 14px 28px;
    border-radius: var(--radius-lg);
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 1px;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.1), transparent);
    transition: left 0.5s ease;
}

.btn:hover::before {
    left: 100%;
}

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

.btn-primary {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: white;
    box-shadow: 0 4px 20px var(--glow-primary), 0 0 40px rgba(168, 85, 247, 0.1);
}

.btn-primary:hover {
    box-shadow: 0 6px 30px var(--glow-primary), 0 0 60px rgba(168, 85, 247, 0.2);
    transform: translateY(-2px);
}

.btn-secondary {
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    backdrop-filter: blur(10px);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--bg-glass-hover);
    border-color: var(--border-glass-hover);
    transform: translateY(-2px);
}

.btn-gold {
    background: linear-gradient(135deg, #f59e0b, #fbbf24, #f59e0b);
    color: #1a0a00;
    box-shadow: 0 4px 20px var(--glow-gold);
    font-weight: 700;
}

.btn-gold:hover {
    box-shadow: 0 6px 30px var(--glow-gold), 0 0 60px rgba(251, 191, 36, 0.2);
    transform: translateY(-2px);
}

.btn-icon {
    width: 44px;
    height: 44px;
    padding: 0;
    border-radius: var(--radius-full);
    font-size: 1.2rem;
}

.btn-sm {
    padding: 8px 16px;
    font-size: 0.85rem;
    border-radius: var(--radius-md);
}

/* ---------- Level Select Screen ---------- */
#level-screen {
    gap: var(--gap-lg);
}

.level-screen-title {
    font-family: var(--font-display);
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent-gold), #f59e0b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.level-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: var(--gap-sm);
    width: 100%;
    max-width: 400px;
    max-height: 60vh;
    overflow-y: auto;
    padding: var(--gap-sm);
    scrollbar-width: thin;
    scrollbar-color: rgba(255,255,255,0.2) transparent;
}

.level-grid::-webkit-scrollbar {
    width: 4px;
}

.level-grid::-webkit-scrollbar-thumb {
    background: rgba(255,255,255,0.2);
    border-radius: 4px;
}

.level-btn {
    aspect-ratio: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    border-radius: var(--radius-md);
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 700;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.level-btn .stars {
    font-size: 0.5rem;
    letter-spacing: 1px;
    opacity: 0.7;
}

.level-btn.unlocked:hover {
    background: var(--bg-glass-hover);
    border-color: var(--accent-primary);
    transform: scale(1.05);
    box-shadow: 0 0 20px var(--glow-primary);
}

.level-btn.locked {
    opacity: 0.3;
    cursor: not-allowed;
}

.level-btn.locked::after {
    content: '🔒';
    position: absolute;
    font-size: 0.7rem;
}

.level-btn.completed {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.2), rgba(16, 185, 129, 0.05));
    border-color: rgba(16, 185, 129, 0.4);
}

.level-btn.current {
    background: linear-gradient(135deg, rgba(168, 85, 247, 0.2), rgba(99, 102, 241, 0.1));
    border-color: var(--accent-primary);
    box-shadow: 0 0 20px var(--glow-primary);
    animation: currentLevelPulse 2s ease-in-out infinite;
}

@keyframes currentLevelPulse {
    0%, 100% { box-shadow: 0 0 20px var(--glow-primary); }
    50% { box-shadow: 0 0 35px var(--glow-primary); }
}

/* ---------- Game Screen ---------- */
#game-screen {
    justify-content: space-between;
    padding-top: env(safe-area-inset-top, 8px);
    padding-bottom: 6px;
    gap: 4px;
}

/* HUD */
.game-hud {
    width: 100%;
    max-width: 500px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    z-index: var(--z-hud);
    gap: var(--gap-sm);
    flex-shrink: 0;
}

.hud-left, .hud-right {
    display: flex;
    align-items: center;
    gap: var(--gap-sm);
}

.hud-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-md);
    padding: 6px 12px;
    min-width: 60px;
}

.hud-stat-label {
    font-size: 0.6rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    font-weight: 500;
}

.hud-stat-value {
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
}

.hud-stat-value.warning {
    color: var(--accent-rose);
    animation: warningPulse 0.5s ease-in-out infinite;
}

@keyframes warningPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.hud-level-badge {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    padding: 6px 14px;
    border-radius: var(--radius-md);
    font-family: var(--font-display);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 1px;
    box-shadow: 0 2px 10px var(--glow-primary);
}

/* Puzzle Grid Container */
.puzzle-container {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    max-width: 500px;
    position: relative;
    min-height: 0;
    overflow: hidden;
}

.puzzle-grid {
    display: grid;
    gap: 4px;
    padding: 8px;
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-xl);
    box-shadow:
        0 20px 60px rgba(0, 0, 0, 0.5),
        0 0 80px rgba(168, 85, 247, 0.05),
        inset 0 1px 0 rgba(255, 255, 255, 0.05);
    position: relative;
    transition: all var(--transition-slow);
}

/* Puzzle Tiles */
.puzzle-tile {
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    font-family: var(--font-display);
    font-weight: 800;
    cursor: pointer;
    transition: transform 0.2s cubic-bezier(0.25, 0.46, 0.45, 0.94),
                box-shadow 0.2s ease,
                opacity 0.2s ease;
    position: relative;
    overflow: hidden;
    background: var(--tile-bg);
    color: var(--tile-text);
    box-shadow:
        0 4px 12px rgba(0, 0, 0, 0.3),
        0 2px 4px rgba(0, 0, 0, 0.2),
        inset 0 1px 0 rgba(255, 255, 255, 0.2),
        inset 0 -2px 0 rgba(0, 0, 0, 0.15);
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

.puzzle-tile::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 40%;
    background: linear-gradient(180deg, rgba(255,255,255,0.15), transparent);
    border-radius: var(--radius-md) var(--radius-md) 50% 50%;
    pointer-events: none;
}

.puzzle-tile:hover {
    box-shadow:
        0 6px 20px rgba(0, 0, 0, 0.4),
        0 0 20px var(--tile-shadow),
        inset 0 1px 0 rgba(255, 255, 255, 0.25),
        inset 0 -2px 0 rgba(0, 0, 0, 0.15);
    transform: scale(1.02);
}

.puzzle-tile:active {
    transform: scale(0.98);
}

.puzzle-tile.empty {
    background: rgba(0, 0, 0, 0.2) !important;
    box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.3) !important;
    cursor: default;
    border: 1px dashed rgba(255, 255, 255, 0.08);
}

.puzzle-tile.empty::before {
    display: none;
}

.puzzle-tile.sliding {
    z-index: 10;
    transition: transform 0.15s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.puzzle-tile.correct {
    box-shadow:
        0 4px 12px rgba(0, 0, 0, 0.3),
        0 0 15px rgba(16, 185, 129, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.2),
        inset 0 -2px 0 rgba(0, 0, 0, 0.15);
}

.puzzle-tile.hint-highlight {
    animation: hintPulse 1s ease-in-out 3;
}

@keyframes hintPulse {
    0%, 100% { box-shadow: 0 4px 12px rgba(0,0,0,0.3); }
    50% { box-shadow: 0 4px 12px rgba(0,0,0,0.3), 0 0 30px rgba(251, 191, 36, 0.6); }
}

/* Tile themes per level group */
.theme-cosmic .puzzle-tile:not(.empty) {
    --tile-bg: linear-gradient(135deg, #6366f1, #a855f7);
    --tile-shadow: rgba(99, 102, 241, 0.5);
}
.theme-ocean .puzzle-tile:not(.empty) {
    --tile-bg: linear-gradient(135deg, #0891b2, #06b6d4);
    --tile-shadow: rgba(6, 182, 212, 0.5);
}
.theme-forest .puzzle-tile:not(.empty) {
    --tile-bg: linear-gradient(135deg, #059669, #10b981);
    --tile-shadow: rgba(16, 185, 129, 0.5);
}
.theme-volcano .puzzle-tile:not(.empty) {
    --tile-bg: linear-gradient(135deg, #dc2626, #f97316);
    --tile-shadow: rgba(249, 115, 22, 0.5);
}
.theme-neon .puzzle-tile:not(.empty) {
    --tile-bg: linear-gradient(135deg, #ec4899, #8b5cf6);
    --tile-shadow: rgba(236, 72, 153, 0.5);
}
.theme-crystal .puzzle-tile:not(.empty) {
    --tile-bg: linear-gradient(135deg, #7dd3fc, #c4b5fd);
    --tile-shadow: rgba(125, 211, 252, 0.5);
    color: #1e1b4b;
    text-shadow: 0 1px 2px rgba(255, 255, 255, 0.3);
}
.theme-galaxy .puzzle-tile:not(.empty) {
    --tile-bg: linear-gradient(135deg, #7c3aed, #fbbf24);
    --tile-shadow: rgba(124, 58, 237, 0.5);
}
.theme-inferno .puzzle-tile:not(.empty) {
    --tile-bg: linear-gradient(135deg, #be123c, #f97316);
    --tile-shadow: rgba(190, 18, 60, 0.5);
}
.theme-ultimate .puzzle-tile:not(.empty) {
    --tile-bg: linear-gradient(135deg, #a855f7, #ec4899, #f97316);
    --tile-shadow: rgba(168, 85, 247, 0.5);
    background-size: 200% 200%;
    animation: ultimateTile 3s ease infinite;
}

@keyframes ultimateTile {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* ---------- Power-ups Bar ---------- */
.powerups-bar {
    width: 100%;
    max-width: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    flex-shrink: 0;
    padding: 0 4px;
}

.powerup-btn {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 6px 10px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-md);
    font-size: 0.75rem;
    font-weight: 600;
    transition: all var(--transition-normal);
    white-space: nowrap;
}

.powerup-btn:hover:not(:disabled) {
    background: var(--bg-glass-hover);
    border-color: var(--accent-gold);
    box-shadow: 0 0 15px var(--glow-gold);
    transform: translateY(-2px);
}

.powerup-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.powerup-btn .count {
    background: var(--accent-gold);
    color: #1a0a00;
    width: 20px;
    height: 20px;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    font-weight: 800;
}

/* ---------- Game Controls ---------- */
.game-controls {
    width: 100%;
    max-width: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--gap-sm);
    flex-shrink: 0;
    padding-bottom: env(safe-area-inset-bottom, 4px);
}

/* ---------- Modal / Overlay System ---------- */
.modal-overlay {
    position: fixed;
    inset: 0;
    z-index: var(--z-modal);
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(8px);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-slow);
    padding: var(--gap-md);
}

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

.modal {
    background: rgba(15, 15, 35, 0.95);
    backdrop-filter: blur(30px);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-2xl);
    padding: var(--gap-2xl) var(--gap-xl);
    max-width: 400px;
    width: 100%;
    text-align: center;
    transform: scale(0.9) translateY(20px);
    transition: transform var(--transition-bounce);
    position: relative;
    overflow: hidden;
}

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

.modal::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
}

.modal-icon {
    font-size: 3.5rem;
    margin-bottom: var(--gap-md);
    display: block;
    animation: modalIconBounce 0.6s cubic-bezier(0.34, 1.56, 0.64, 1) 0.3s both;
}

@keyframes modalIconBounce {
    from { transform: scale(0) rotate(-20deg); opacity: 0; }
    to { transform: scale(1) rotate(0deg); opacity: 1; }
}

.modal-title {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: var(--gap-sm);
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-gold));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.modal-subtitle {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: var(--gap-lg);
    line-height: 1.5;
}

.modal-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--gap-sm);
    margin-bottom: var(--gap-lg);
}

.modal-stat {
    background: var(--bg-glass);
    border-radius: var(--radius-md);
    padding: var(--gap-sm);
}

.modal-stat-label {
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    margin-bottom: 2px;
}

.modal-stat-value {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 700;
}

.modal-stars {
    font-size: 2rem;
    letter-spacing: 8px;
    margin-bottom: var(--gap-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--gap-sm);
}

.modal-star {
    transition: all 0.3s ease;
    filter: grayscale(1) opacity(0.3);
}

.modal-star.earned {
    filter: none;
    animation: starEarn 0.5s cubic-bezier(0.34, 1.56, 0.64, 1) both;
}

.modal-star:nth-child(1) { animation-delay: 0.5s; }
.modal-star:nth-child(2) { animation-delay: 0.7s; }
.modal-star:nth-child(3) { animation-delay: 0.9s; }

@keyframes starEarn {
    from { transform: scale(0) rotate(-180deg); }
    to { transform: scale(1) rotate(0deg); }
}

.modal-buttons {
    display: flex;
    flex-direction: column;
    gap: var(--gap-sm);
}

/* ---------- Tutorial Overlay ---------- */
.tutorial-overlay {
    position: fixed;
    inset: 0;
    z-index: var(--z-overlay);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(10px);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-slow);
    padding: var(--gap-lg);
}

.tutorial-overlay.active {
    opacity: 1;
    visibility: visible;
}

.tutorial-card {
    background: rgba(15, 15, 35, 0.95);
    backdrop-filter: blur(30px);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-2xl);
    padding: var(--gap-xl);
    max-width: 400px;
    width: 100%;
    text-align: center;
}

.tutorial-step-indicator {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    margin-bottom: var(--gap-lg);
}

.tutorial-dot {
    width: 8px;
    height: 8px;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.2);
    transition: all var(--transition-normal);
}

.tutorial-dot.active {
    background: var(--accent-primary);
    width: 24px;
    border-radius: 4px;
}

.tutorial-icon {
    font-size: 3rem;
    margin-bottom: var(--gap-md);
}

.tutorial-title {
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: var(--gap-sm);
    color: var(--accent-gold);
}

.tutorial-text {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--gap-lg);
}

.tutorial-buttons {
    display: flex;
    gap: var(--gap-sm);
    justify-content: center;
}

/* ---------- Settings Panel ---------- */
.settings-content {
    max-width: 400px;
    width: 100%;
}

.settings-title {
    font-family: var(--font-display);
    font-size: 1.3rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--gap-lg);
    color: var(--accent-primary);
}

.setting-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--gap-md) 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.setting-label {
    font-size: 0.95rem;
    font-weight: 500;
}

/* Toggle switch */
.toggle {
    position: relative;
    width: 48px;
    height: 26px;
    border-radius: 13px;
    background: rgba(255, 255, 255, 0.1);
    cursor: pointer;
    transition: background var(--transition-normal);
    border: 1px solid transparent;
}

.toggle.on {
    background: var(--accent-primary);
}

.toggle::after {
    content: '';
    position: absolute;
    top: 3px;
    left: 3px;
    width: 20px;
    height: 20px;
    border-radius: var(--radius-full);
    background: white;
    transition: transform var(--transition-normal);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.toggle.on::after {
    transform: translateX(22px);
}

/* ---------- Toast Notifications ---------- */
.toast-container {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    z-index: var(--z-toast);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--gap-sm);
    pointer-events: none;
}

.toast {
    background: rgba(15, 15, 35, 0.95);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-lg);
    padding: 10px 20px;
    font-size: 0.9rem;
    font-weight: 600;
    white-space: nowrap;
    animation: toastIn 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.toast.success {
    border-color: rgba(16, 185, 129, 0.4);
    color: var(--accent-emerald);
}

.toast.warning {
    border-color: rgba(251, 191, 36, 0.4);
    color: var(--accent-gold);
}

.toast.error {
    border-color: rgba(244, 63, 94, 0.4);
    color: var(--accent-rose);
}

.toast.info {
    border-color: rgba(168, 85, 247, 0.4);
    color: var(--accent-primary);
}

.toast.fade-out {
    animation: toastOut 0.3s ease forwards;
}

@keyframes toastIn {
    from { transform: translateY(-20px) scale(0.9); opacity: 0; }
    to { transform: translateY(0) scale(1); opacity: 1; }
}

@keyframes toastOut {
    from { transform: translateY(0) scale(1); opacity: 1; }
    to { transform: translateY(-20px) scale(0.9); opacity: 0; }
}

/* ---------- Combo Meter ---------- */
.combo-display {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: var(--z-toast);
    pointer-events: none;
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 900;
    color: var(--accent-gold);
    opacity: 0;
    text-shadow: 0 0 20px var(--glow-gold), 0 0 40px var(--glow-gold);
}

.combo-display.show {
    animation: comboShow 0.8s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

@keyframes comboShow {
    0% { transform: translate(-50%, -50%) scale(0.5); opacity: 0; }
    30% { transform: translate(-50%, -50%) scale(1.3); opacity: 1; }
    100% { transform: translate(-50%, -60%) scale(1); opacity: 0; }
}

/* ---------- Score Popup ---------- */
.score-popup {
    position: absolute;
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--accent-gold);
    pointer-events: none;
    z-index: var(--z-toast);
    animation: scorePopup 0.8s ease-out forwards;
    text-shadow: 0 0 10px var(--glow-gold);
}

@keyframes scorePopup {
    0% { transform: translateY(0) scale(0.5); opacity: 0; }
    20% { transform: translateY(-10px) scale(1.2); opacity: 1; }
    100% { transform: translateY(-50px) scale(1); opacity: 0; }
}

/* ---------- Loading Screen ---------- */
.loading-screen {
    position: fixed;
    inset: 0;
    z-index: 9999;
    background: var(--bg-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--gap-lg);
    transition: opacity 0.5s ease;
}

.loading-screen.hidden {
    opacity: 0;
    pointer-events: none;
}

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 3px solid rgba(168, 85, 247, 0.2);
    border-top-color: var(--accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-text {
    font-family: var(--font-display);
    font-size: 0.9rem;
    color: var(--text-secondary);
    letter-spacing: 3px;
}

/* ---------- Progress Bar (Level transition) ---------- */
.level-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-gold));
    z-index: var(--z-overlay);
    transition: width 0.3s ease;
    box-shadow: 0 0 10px var(--glow-primary);
}

/* ---------- Responsive ---------- */

/* Mobile phones */
@media (max-width: 480px) {
    :root {
        --gap-xl: 16px;
        --gap-2xl: 24px;
    }

    .screen {
        padding: 8px;
    }

    #game-screen {
        padding-top: 6px;
        padding-bottom: 4px;
        gap: 3px;
    }

    .menu-icon {
        width: 80px;
        height: 80px;
    }

    .menu-title {
        font-size: clamp(1.6rem, 8vw, 2.5rem);
    }

    .menu-subtitle {
        font-size: 0.8rem;
        letter-spacing: 3px;
    }

    #menu-screen {
        gap: var(--gap-md);
    }

    .menu-buttons {
        gap: 10px;
        max-width: 280px;
    }

    .btn {
        padding: 12px 20px;
        font-size: 0.9rem;
    }

    .level-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 6px;
    }

    .game-hud {
        gap: 4px;
    }

    .hud-left, .hud-right {
        gap: 4px;
    }

    .hud-stat {
        padding: 3px 6px;
        min-width: 44px;
        border-radius: 8px;
    }

    .hud-stat-value {
        font-size: 0.8rem;
    }

    .hud-stat-label {
        font-size: 0.45rem;
        letter-spacing: 0.5px;
    }

    .hud-level-badge {
        padding: 4px 10px;
        font-size: 0.65rem;
    }

    .powerup-btn {
        padding: 5px 8px;
        font-size: 0.65rem;
        gap: 3px;
    }

    .powerup-btn .count {
        width: 16px;
        height: 16px;
        font-size: 0.6rem;
    }

    .btn-icon {
        width: 38px;
        height: 38px;
        font-size: 1rem;
    }

    .modal {
        padding: var(--gap-lg) var(--gap-md);
        border-radius: var(--radius-xl);
    }

    .modal-icon {
        font-size: 2.5rem;
    }

    .modal-title {
        font-size: 1.2rem;
    }

    .modal-stats {
        grid-template-columns: repeat(3, 1fr);
        gap: 4px;
    }

    .modal-stat {
        padding: 6px;
    }

    .modal-stat-value {
        font-size: 0.95rem;
    }

    .modal-stars {
        font-size: 1.5rem;
        gap: 6px;
        margin-bottom: var(--gap-md);
    }
}

/* Very small phones */
@media (max-width: 360px) {
    .menu-icon {
        width: 64px;
        height: 64px;
    }

    .menu-title {
        font-size: 1.5rem;
    }

    .level-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 4px;
    }

    .level-btn {
        font-size: 0.9rem;
    }

    .hud-stat {
        padding: 2px 5px;
        min-width: 38px;
    }

    .hud-stat-value {
        font-size: 0.7rem;
    }

    .powerup-btn {
        padding: 4px 6px;
        font-size: 0.6rem;
    }

    .btn-icon {
        width: 34px;
        height: 34px;
        font-size: 0.9rem;
    }
}

/* Short phones (viewport height < 700) */
@media (max-height: 700px) and (orientation: portrait) {
    #game-screen {
        gap: 2px;
        padding-top: 4px;
        padding-bottom: 2px;
    }

    .game-hud {
        gap: 3px;
    }

    .hud-stat {
        padding: 2px 6px;
    }

    .powerup-btn {
        padding: 4px 8px;
    }

    .btn-icon {
        width: 36px;
        height: 36px;
    }
}

/* Tablets */
@media (min-width: 768px) {
    .puzzle-grid {
        gap: 6px;
        padding: 12px;
    }

    .modal {
        max-width: 440px;
    }
}

/* Desktop */
@media (min-width: 1024px) {
    .menu-icon {
        width: 140px;
        height: 140px;
    }

    .puzzle-grid {
        gap: 8px;
        padding: 14px;
    }
}

/* ---------- Landscape mode adjustments ---------- */
@media (orientation: landscape) and (max-height: 500px) {
    #game-screen {
        flex-direction: column;
        justify-content: space-between;
        padding: 4px 8px;
        gap: 2px;
    }

    .game-hud {
        max-width: none;
    }

    .puzzle-container {
        max-width: 70vh;
    }

    .powerups-bar {
        gap: 4px;
    }

    .powerup-btn {
        padding: 3px 6px;
        font-size: 0.6rem;
    }

    .btn-icon {
        width: 32px;
        height: 32px;
        font-size: 0.85rem;
    }

    .game-controls {
        gap: 4px;
        padding-bottom: 2px;
    }

    /* Menu in landscape */
    #menu-screen {
        gap: 12px;
    }

    .menu-icon {
        width: 60px;
        height: 60px;
    }

    .menu-title {
        font-size: 1.5rem;
    }

    .menu-subtitle {
        font-size: 0.7rem;
        display: none;
    }

    .menu-buttons {
        flex-direction: row;
        flex-wrap: wrap;
        justify-content: center;
        max-width: 500px;
        gap: 8px;
    }

    .menu-buttons .btn {
        padding: 8px 16px;
        font-size: 0.8rem;
    }
}

/* ---------- Accessibility ---------- */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}

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

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

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

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.25);
}