/* BOOK BACKGROUND */
.bb-scene {
    position: fixed;
    inset: 0;
    z-index: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    perspective: 1400px;
    background: transparent;
    overflow: hidden;
    pointer-events: none;
    user-select: none;
}

.bb-book-wrap {
    position: relative;
    transform-style: preserve-3d;
    animation: bbBookFloat 8s ease-in-out infinite;
}

@keyframes bbBookFloat {

    0%,
    100% {
        transform: rotateX(4deg) rotateY(-2deg) translateY(0px);
    }

    50% {
        transform: rotateX(6deg) rotateY(1deg) translateY(-8px);
    }
}

.bb-book {
    position: relative;
    width: 560px;
    height: 370px;
    transform-style: preserve-3d;
}

.bb-spine {
    position: absolute;
    left: 50%;
    top: 0;
    transform: translateX(-50%);
    width: 10px;
    height: 100%;
    background: linear-gradient(90deg, rgba(224, 242, 254, 0.4), rgba(186, 230, 253, 0.9), rgba(224, 242, 254, 0.4));
    border-left: 1px solid rgba(186, 230, 253, 0.8);
    border-right: 1px solid rgba(186, 230, 253, 0.8);
    z-index: 10;
    border-radius: 5px;
    box-shadow: 0 0 15px rgba(56, 189, 248, 0.2);
}

.bb-page {
    position: absolute;
    top: 0;
    width: 274px;
    height: 370px;
    transform-style: preserve-3d;
    overflow: hidden;
}

.bb-page-left {
    right: 50%;
    margin-right: 5px;
    transform-origin: right center;
    border-radius: 12px 0 0 12px;
    animation: bbLeftBreath 8s ease-in-out infinite;
}

.bb-page-right {
    left: 50%;
    margin-left: 5px;
    transform-origin: left center;
    border-radius: 0 12px 12px 0;
    animation: bbRightBreath 8s ease-in-out infinite;
}

@keyframes bbLeftBreath {

    0%,
    100% {
        transform: perspective(1200px) rotateY(6deg);
    }

    50% {
        transform: perspective(1200px) rotateY(2deg);
    }
}

@keyframes bbRightBreath {

    0%,
    100% {
        transform: perspective(1200px) rotateY(-6deg);
    }

    50% {
        transform: perspective(1200px) rotateY(-2deg);
    }
}

.bb-page-surface {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(240, 249, 255, 0.9) 0%, rgba(224, 242, 254, 0.5) 100%);
    border: 1px solid rgba(186, 230, 253, 0.7);
    box-shadow: 0 8px 32px rgba(14, 165, 233, 0.05);
    display: flex;
    flex-direction: column;
    padding: 24px;
}

.bb-page-left .bb-page-surface {
    background: linear-gradient(225deg, rgba(240, 249, 255, 0.9) 0%, rgba(224, 242, 254, 0.5) 100%);
}

.bb-ghost {
    position: absolute;
    top: 0;
    right: 50%;
    margin-right: 5px;
    width: 274px;
    height: 370px;
    transform-origin: right center;
    background: linear-gradient(225deg, rgba(224, 242, 254, 0.7), transparent);
    border: 1px solid rgba(186, 230, 253, 0.6);
    border-radius: 12px 0 0 12px;
    animation: bbGhostTurn 7s ease-in-out infinite;
    pointer-events: none;
    z-index: 5;
    backface-visibility: hidden;
}

@keyframes bbGhostTurn {

    0%,
    20% {
        transform: perspective(1200px) rotateY(6deg);
        opacity: 0;
    }

    35% {
        transform: perspective(1200px) rotateY(60deg);
        opacity: 0.8;
    }

    50%,
    100% {
        transform: perspective(1200px) rotateY(90deg);
        opacity: 0;
    }
}

.bb-page-lines {
    position: absolute;
    inset: 0;
    z-index: 1;
    pointer-events: none;
    background-image: repeating-linear-gradient(transparent 0px, transparent 21px, rgba(56, 189, 248, 0.15) 21px, rgba(56, 189, 248, 0.15) 22px);
    background-position: 0 36px;
}

.bb-page-header {
    font-family: monospace;
    font-size: 10px;
    font-weight: 800;
    color: rgba(30, 64, 175, 0.6);
    text-align: center;
    letter-spacing: 0.1em;
    margin-bottom: 12px;
    padding-bottom: 6px;
    border-bottom: 1px dashed rgba(59, 130, 246, 0.3);
}

.bb-page-text {
    font-family: monospace;
    color: rgba(30, 64, 175, 0.5);
    font-weight: 600;
    font-size: 9.5px;
    line-height: 22px;
    flex: 1;
}

.bb-text-right {
    text-align: right;
}

.bb-text-left {
    text-align: left;
}

.bb-wl {
    display: block;
    overflow: hidden;
    white-space: nowrap;
    animation: bbTypeReveal 10s linear infinite;
}

@keyframes bbTypeReveal {
    0% {
        max-width: 0;
        opacity: 0;
    }

    10% {
        opacity: 1;
    }

    40%,
    80% {
        max-width: 100%;
        opacity: 1;
    }

    95%,
    100% {
        max-width: 0;
        opacity: 0;
    }
}

.bg-knowledge-icon {
    position: absolute;
    color: rgba(56, 189, 248, 0.25);
    pointer-events: none;
    z-index: 1;
    animation: floatUp 25s linear infinite;
}

@keyframes floatUp {
    0% {
        transform: translateY(110vh) rotate(-15deg) scale(0.8);
        opacity: 0;
    }

    10% {
        opacity: 1;
    }

    85% {
        opacity: 1;
    }

    100% {
        transform: translateY(-20vh) rotate(25deg) scale(1.2);
        opacity: 0;
    }
}

.bg-knowledge-word {
    position: absolute;
    color: var(--word-color, rgba(148, 163, 184, 0.5));
    font-family: monospace;
    font-weight: 700;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    pointer-events: none;
    z-index: 1;
    animation: floatWordBg 15s ease-in-out infinite alternate;
}

@keyframes floatWordBg {
    0% {
        transform: translateY(0px) translateX(0px);
    }

    100% {
        transform: translateY(-40px) translateX(20px);
    }
}

.typewriter-inner {
    display: inline-block;
    overflow: hidden;
    white-space: nowrap;
    border-right: 2px solid;
    width: 0;
    animation: typeBgWord 12s steps(30, end) infinite;
}

@keyframes typeBgWord {

    0%,
    5% {
        width: 0;
        opacity: 0;
        border-right-color: transparent;
    }

    10% {
        opacity: 1;
        border-right-color: var(--word-color);
    }

    35%,
    65% {
        width: 100%;
        opacity: 1;
        border-right-color: transparent;
    }

    70%,
    100% {
        width: 0;
        opacity: 0;
        border-right-color: transparent;
    }
}

@keyframes float3D {

    0%,
    100% {
        transform: translateY(0) rotateX(1deg) rotateY(-1deg);
    }

    50% {
        transform: translateY(-10px) rotateX(3deg) rotateY(1deg);
    }
}

@keyframes cycleWord {

    0%,
    20% {
        opacity: 0;
        transform: translateY(10px) scale(0.9);
    }

    25%,
    45% {
        opacity: 1;
        transform: translateY(0) scale(1);
    }

    50%,
    100% {
        opacity: 0;
        transform: translateY(-10px) scale(1.05);
    }
}

@keyframes confettiFirework {
    0% {
        transform: translate(0, 0) rotate(0deg) scale(1);
        opacity: 1;
    }

    100% {
        transform: translate(var(--tx), var(--ty)) rotate(var(--rot)) scale(0);
        opacity: 0;
    }
}