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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #2d3436 0%, #000000 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 24px 24px;
    margin: 0;
    overflow-x: hidden;
    transition: background 0.5s ease;
}

.container {
    text-align: center;
    width: 100%;
    max-width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 30px;
    overflow-x: hidden;
}

.display-board {
    background: #2c2c2c;
    padding: clamp(15px, 4vw, 40px);
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255, 255, 255, 0.05);
    display: inline-block;
    border: 3px solid #1a1a1a;
    box-sizing: border-box;
    max-width: 100%;
    overflow: hidden;
}

.display-row {
    display: flex;
    gap: clamp(3px, 0.6vw, 8px);
    margin-bottom: 10px;
    justify-content: center;
}

.display-row:last-child {
    margin-bottom: 0;
}

.display-container {
    position: relative;
    padding-bottom: 120px; /* leave space so QR overlay doesn't cover text */
}

.flap-container {
    width: clamp(20px, 4.2vw, 60px);
    height: clamp(32px, 6vw, 80px);
    position: relative;
    perspective: 1000px;
}

.flap {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
}

.flap-half {
    position: absolute;
    width: 100%;
    height: 50%;
    overflow: hidden;
    background: #1a1a1a;
    border: 2px solid #0a0a0a;
}

.flap-top {
    top: 0;
    border-radius: 4px 4px 0 0;
    background: linear-gradient(to bottom, #1f1f1f 0%, #1a1a1a 100%);
}

.flap-bottom {
    bottom: 0;
    border-radius: 0 0 4px 4px;
    background: linear-gradient(to bottom, #1a1a1a 0%, #0f0f0f 100%);
}

.flap-content {
    position: absolute;
    width: 100%;
    height: 200%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: clamp(20px, 4vw, 52px);
    font-weight: 600;
    color: #ffffff;
    text-shadow: 0 0 1px rgba(0, 0, 0, 0.3);
    font-family: 'Menlo', 'SF Mono', 'Roboto Mono', 'Consolas', monospace;
    line-height: 1;
    left: 0;
    letter-spacing: 0;
}

.flap-top .flap-content {
    top: 1px;
}

.flap-bottom .flap-content {
    top: calc(-100% - 1px);
}

/* Animated flipping flap */
.flap-flip {
    position: absolute;
    top: 0;
    width: 100%;
    height: 50%;
    overflow: hidden;
    transform-origin: bottom;
    background: linear-gradient(to bottom, #1f1f1f 0%, #1a1a1a 100%);
    border: 2px solid #0a0a0a;
    border-radius: 4px 4px 0 0;
    backface-visibility: hidden;
    z-index: 10;
}

.flap-flip .flap-content {
    top: 0;
}

.flap-flip.flipping {
    animation: flip 0.05s ease-in-out;
}

@keyframes flip {
    0% {
        transform: rotateX(0deg);
        filter: brightness(1);
    }
    50% {
        transform: rotateX(-90deg);
        filter: brightness(0.6);
    }
    100% {
        transform: rotateX(-180deg);
        filter: brightness(1);
        opacity: 0;
    }
}

/* Shadow between flaps */
.flap-container::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: 2px;
    background: rgba(0, 0, 0, 0.8);
    z-index: 5;
    transform: translateY(-1px);
}

.controls {
    display: flex;
    gap: 12px;
    justify-content: center;
    align-items: flex-start;
    flex-wrap: wrap;
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    padding: 30px;
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    width: 100%;
    max-width: 600px;
    box-sizing: border-box;
}

/* Display: tap-to-enable-sound overlay */
#audioPrompt {
    position: fixed;
    inset: 0;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    pointer-events: auto;
    background: transparent;
    z-index: 90; /* below QR overlay (100) */
}

#audioPrompt span {
    margin-bottom: 24px;
    padding: 8px 16px;
    border-radius: 999px;
    background: rgba(0, 0, 0, 0.7);
    color: rgba(255, 255, 255, 0.9);
    font-size: 13px;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    backdrop-filter: blur(14px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.55);
    cursor: pointer;
}

#audioPrompt.hidden {
    display: none;
}

/* Display: small-screen message overlay */
#smallScreenMessage {
    position: fixed;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    pointer-events: auto;
    background: transparent;
    z-index: 90; /* similar layer as audio prompt */
}

#smallScreenMessage span {
    margin-bottom: 0;
    padding: 8px 16px;
    border-radius: 999px;
    background: rgba(0, 0, 0, 0.7);
    color: rgba(255, 255, 255, 0.9);
    font-size: 13px;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    backdrop-filter: blur(14px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.55);
}

#smallScreenMessage.hidden {
    display: none;
}

/* Display page QR overlay */
#qr-container {
    position: fixed;
    right: 24px;
    bottom: 24px;
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: center;
    gap: 0;
    padding: 8px 10px;
    border-radius: 14px;
    background: rgba(0, 0, 0, 0.75);
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(12px);
    z-index: 100;
}

#qrcode {
    width: 112px;
    height: 112px;
    background: #ffffff;
    border-radius: 8px;
}

.display-container {
    position: relative;
}

#textInput {
    padding: 16px 20px;
    font-size: 17px;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    width: 100%;
    font-family: 'Courier New', monospace;
    background: rgba(255, 255, 255, 0.98);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.15);
    resize: vertical;
    transition: all 0.3s ease;
}

#textInput:focus {
    outline: none;
    border-color: rgba(102, 126, 234, 0.5);
    box-shadow: 0 4px 20px rgba(102, 126, 234, 0.3);
    transform: translateY(-1px);
}

button {
    padding: 14px 32px;
    font-size: 15px;
    font-weight: 600;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    color: white;
    letter-spacing: 0.3px;
    flex: 1;
    min-width: 140px;
}

button:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(102, 126, 234, 0.45);
}

button:active {
    transform: translateY(-1px);
}

/* Remote buttons: subtle, modern color scheme */
#displayBtn {
    background: linear-gradient(135deg, #3d4f5f 0%, #5a7186 100%); /* slate blue */
    box-shadow: 0 3px 12px rgba(61, 79, 95, 0.4);
}

#displayBtn:hover {
    box-shadow: 0 6px 18px rgba(61, 79, 95, 0.5);
}

#displayBtn:active {
    box-shadow: 0 3px 12px rgba(61, 79, 95, 0.4);
}

#randomBtn {
    background: linear-gradient(135deg, #2d5a5a 0%, #4a7c7c 100%); /* muted teal */
    box-shadow: 0 3px 12px rgba(45, 90, 90, 0.4);
}

#randomBtn:hover {
    box-shadow: 0 6px 18px rgba(45, 90, 90, 0.5);
}

#randomBtn:active {
    box-shadow: 0 3px 12px rgba(45, 90, 90, 0.4);
}

#funnyBtn {
    background: linear-gradient(135deg, #7a5c1e 0%, #a67c28 100%); /* warm amber */
    box-shadow: 0 3px 12px rgba(122, 92, 30, 0.4);
}

#funnyBtn:hover {
    box-shadow: 0 6px 18px rgba(122, 92, 30, 0.5);
}

#funnyBtn:active {
    box-shadow: 0 3px 12px rgba(122, 92, 30, 0.4);
}

#clearBtn {
    background: linear-gradient(135deg, #6b3a3a 0%, #8f5050 100%); /* muted burgundy */
    box-shadow: 0 3px 12px rgba(107, 58, 58, 0.4);
}

#clearBtn:hover {
    box-shadow: 0 6px 18px rgba(107, 58, 58, 0.5);
}

#clearBtn:active {
    box-shadow: 0 3px 12px rgba(107, 58, 58, 0.4);
}

/* Controller page specifics */
.controller-container {
    max-width: 640px;
}

.controller-title {
    color: #ffffff;
    margin-bottom: 6px;
    font-size: 26px;
}

.controller-subtitle {
    color: rgba(255, 255, 255, 0.75);
    margin-bottom: 12px;
}

.controller-room-id {
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.room-error {
    color: #ff6b6b;
    margin-bottom: 16px;
    font-size: 14px;
}

.remote-qr-wrapper {
    margin-top: 20px;
    display: flex;
    justify-content: center;
}

#remote-qrcode {
    width: 72px;
    height: 72px;
}


@media (min-width: 1400px) {
    body {
        padding: 16px 24px;
    }

    .display-container {
        padding-bottom: 80px;
    }
}


@media (max-width: 768px) {
    body {
        padding: 20px 10px;
    }
    
    .controls {
        padding: 20px;
        flex-direction: column;
    }
    
    button {
        width: 100%;
        margin-top: 0;
    }
}

@media (max-width: 480px) {
    body {
        padding: 15px 5px;
    }
    
    .controls {
        padding: 15px;
    }
}