:root {
    --bg-base: #020617;
    --board-bg: #0f172a;
    --cell-bg: #1e293b;
    --text-main: #f8fafc;
    --text-dim: #94a3b8;
    
    --accent: #0ea5e9;
    --glow-cyan: rgba(6, 182, 212, 0.5);
    --glow-purple: rgba(168, 85, 247, 0.5);
    
    --cell-size: min(10vw, 42px);
    --board-gap: 2px;
    --board-padding: 8px;
    --tray-cell-size: min(4vw, 18px);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
    touch-action: none;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-base);
    color: var(--text-main);
    overflow: hidden;
    width: 100vw;
    height: 100vh;
    height: 100dvh;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* Background Effects */
.bg-fx {
    position: fixed;
    inset: 0;
    z-index: -2;
    overflow: hidden;
}
.glow-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
    animation: float 10s infinite alternate ease-in-out;
}
.orb-1 {
    width: 300px;
    height: 300px;
    background: var(--glow-cyan);
    top: -100px;
    left: -100px;
}
.orb-2 {
    width: 400px;
    height: 400px;
    background: var(--glow-purple);
    bottom: -150px;
    right: -150px;
    animation-delay: -5s;
}
.scanlines {
    position: fixed;
    inset: 0;
    background: linear-gradient(to bottom, rgba(255,255,255,0), rgba(255,255,255,0) 50%, rgba(0,0,0,0.1) 50%, rgba(0,0,0,0.1));
    background-size: 100% 4px;
    z-index: -1;
    pointer-events: none;
}

@keyframes float {
    0% { transform: translate(0, 0) scale(1); }
    100% { transform: translate(50px, 30px) scale(1.1); }
}

/* Canvas Effects */
#fx-canvas {
    position: fixed;
    inset: 0;
    z-index: 100;
    pointer-events: none;
}

/* App Container */
#app {
    width: 100%;
    max-width: 500px;
    height: 100%;
    position: relative;
    display: flex;
    flex-direction: column;
}

/* Screens */
.screen {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.4s ease;
    z-index: 10;
}
.screen.active {
    opacity: 1;
    pointer-events: auto;
}

/* Home Screen */
#screen-home {
    justify-content: center;
    align-items: center;
    padding: 2rem;
    text-align: center;
}
.title-container {
    margin-bottom: 4rem;
}
.logo-text {
    font-size: 4rem;
    font-weight: 900;
    line-height: 1;
    letter-spacing: -2px;
    background: linear-gradient(135deg, #fff, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    filter: drop-shadow(0 4px 10px rgba(0,0,0,0.5));
}
.logo-text .accent {
    background: linear-gradient(135deg, #0ea5e9, #a855f7);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}
.logo-subtitle {
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 4px;
    color: var(--text-dim);
    margin-top: 1rem;
}
.home-stats {
    margin-bottom: 3rem;
}
.stat-box {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 1rem 2rem;
    display: flex;
    flex-direction: column;
}
.stat-label {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-dim);
    letter-spacing: 2px;
}
.stat-value {
    font-size: 2rem;
    font-weight: 800;
    color: #fff;
}

/* Buttons */
.action-btn {
    position: relative;
    background: linear-gradient(135deg, #0ea5e9, #6366f1);
    border: none;
    border-radius: 20px;
    padding: 1.25rem 3rem;
    font-size: 1.25rem;
    font-weight: 800;
    color: #fff;
    cursor: pointer;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(14, 165, 233, 0.4);
    transition: transform 0.2s cubic-bezier(0.34, 1.56, 0.64, 1);
}
.action-btn:active {
    transform: scale(0.95);
}
.btn-text {
    position: relative;
    z-index: 2;
    letter-spacing: 1px;
}
.btn-shine {
    position: absolute;
    top: 0;
    left: -100%;
    width: 50%;
    height: 100%;
    background: linear-gradient(to right, rgba(255,255,255,0) 0%, rgba(255,255,255,0.3) 50%, rgba(255,255,255,0) 100%);
    transform: skewX(-20deg);
    z-index: 1;
    animation: shine 3s infinite;
}
@keyframes shine {
    0% { left: -100%; }
    20% { left: 200%; }
    100% { left: 200%; }
}
.text-btn {
    background: none;
    border: none;
    color: var(--text-dim);
    font-size: 1rem;
    font-weight: 600;
    margin-top: 1rem;
    cursor: pointer;
    padding: 0.5rem 1rem;
}

/* Game Screen */
#screen-game {
    display: flex;
    flex-direction: column;
    padding: env(safe-area-inset-top, 1rem) 1rem env(safe-area-inset-bottom, 1rem);
}
.game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
    flex: 0 0 auto;
}
.score-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    padding: 0.5rem 1rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 80px;
}
.score-card .label {
    font-size: 0.65rem;
    font-weight: 700;
    color: var(--text-dim);
    letter-spacing: 1px;
}
.score-card .value {
    font-size: 1.5rem;
    font-weight: 800;
    color: #fff;
}
.score-card.best {
    background: transparent;
    border: none;
    backdrop-filter: none;
}
.score-card.best .value {
    font-size: 1.25rem;
    color: var(--text-dim);
}
.combo-text {
    font-size: 1.5rem;
    font-weight: 900;
    color: #f43f5e;
    text-transform: uppercase;
    font-style: italic;
    text-shadow: 0 0 10px rgba(244, 63, 94, 0.5);
    opacity: 0;
    transform: scale(0.5);
    transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}
.combo-text.show {
    opacity: 1;
    transform: scale(1);
    animation: comboPulse 0.5s alternate infinite;
}
@keyframes comboPulse {
    0% { transform: scale(1); }
    100% { transform: scale(1.1); }
}

/* Board */
.board-wrapper {
    flex: 1 1 auto;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
}
.grid-board {
    display: grid;
    grid-template-columns: repeat(8, var(--cell-size));
    grid-template-rows: repeat(8, var(--cell-size));
    gap: var(--board-gap);
    background: var(--board-bg);
    padding: var(--board-padding);
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5), inset 0 2px 5px rgba(255,255,255,0.05);
}
.grid-cell {
    width: var(--cell-size);
    height: var(--cell-size);
    background: var(--cell-bg);
    border-radius: 6px;
    transition: background 0.2s, box-shadow 0.2s;
    position: relative;
}
.grid-cell.filled {
    /* Style applied via inline background color based on block */
    box-shadow: inset 0 2px 6px rgba(255,255,255,0.35), inset 0 -4px 8px rgba(0,0,0,0.35), 0 2px 5px rgba(0,0,0,0.3);
}
.grid-cell.highlight {
    background: rgba(255, 255, 255, 0.2);
}
.grid-cell.highlight-error {
    background: rgba(244, 63, 94, 0.3);
}
.grid-cell.clearing {
    animation: clearPulse 0.4s ease forwards;
}
@keyframes clearPulse {
    0% { transform: scale(1); filter: brightness(1); opacity: 1; }
    50% { transform: scale(1.1); filter: brightness(2); opacity: 1; }
    100% { transform: scale(0); filter: brightness(0); opacity: 0; }
}

/* Footer / Tray */
.game-footer {
    flex: 0 0 auto;
    padding: 1rem 0 2rem 0;
    display: flex;
    justify-content: center;
}
.block-tray {
    display: flex;
    gap: 1.5rem;
    align-items: center;
    justify-content: center;
}
.tray-slot {
    width: 90px;
    height: 90px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px dashed rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

/* Rendered Blocks */
.block-shape {
    display: grid;
    gap: var(--board-gap);
    cursor: grab;
    pointer-events: auto;
    /* Will setup grid template dynamically in JS */
}
.block-shape.dragging {
    position: fixed;
    z-index: 50;
    pointer-events: none;
    transform-origin: center;
    transition: transform 0.1s;
    cursor: grabbing;
}
.block-cell {
    border-radius: 6px;
    box-shadow: inset 0 2px 6px rgba(255,255,255,0.35), inset 0 -4px 8px rgba(0,0,0,0.35), 0 2px 5px rgba(0,0,0,0.3);
}

/* Game Over Modal */
.glass-modal {
    background: rgba(2, 6, 23, 0.8);
    backdrop-filter: blur(12px);
    justify-content: center;
    align-items: center;
    z-index: 200;
}
.modal-content {
    background: rgba(15, 23, 42, 0.9);
    border: 1px solid rgba(255,255,255,0.1);
    padding: 3rem 2rem;
    border-radius: 24px;
    text-align: center;
    box-shadow: 0 20px 50px rgba(0,0,0,0.5);
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 90%;
    max-width: 350px;
    transform: scale(0.9);
    opacity: 0;
    transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}
.screen.active .modal-content {
    transform: scale(1);
    opacity: 1;
}
.gameover-title {
    font-size: 2rem;
    font-weight: 800;
    color: #fff;
    margin-bottom: 2rem;
}
.final-score-container {
    margin-bottom: 2.5rem;
}
.score-label {
    color: var(--text-dim);
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 2px;
}
.score-value {
    font-size: 4rem;
    font-weight: 900;
    color: var(--accent);
    line-height: 1;
    text-shadow: 0 0 20px var(--glow-cyan);
}