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

:root {
    font-size: 100%;

    --size-h1: 1.25rem;
    --size-body: 1rem;
    --size-meta: 0.75rem;
    --size-small: 0.625rem;

    --ls-wide: 0.25em;
    --ls-normal: 0.1em;
    --ls-tight: -0.01em;

    --lh-tight: 1.2;
    --lh-normal: 1.6;

    --color-bg: #0d1013;
    --color-text: #f1f1f1;
    --color-point: #e63946;
    --color-point-sub: #a8dadc;
    
    --op-high: rgba(241, 241, 241, 0.85);
    --op-mid: rgba(241, 241, 241, 0.5);
    --op-low: rgba(241, 241, 241, 0.15);
    --op-ghost: rgba(241, 241, 241, 0.05);

    --color-border: rgba(255, 255, 255, 0.06);
    --color-nav-bg: rgba(13, 16, 19, 0.95);

    --font-data: 'JetBrains Mono', monospace;
}

body, html {
    width: 100%;
    height: 100%;
    background-color: var(--color-bg); 
    color: var(--color-text);
    font-family: 'Pretendard', sans-serif;
    overflow: hidden;
}

#text-system-wrapper {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    height: 100%;
    position: relative;
}

#scrolling-message-container {
    width: 80%;
    max-width: 900px;
    text-align: center;
    position: relative;
}

.message-item {
    position: absolute;
    left: 0;
    right: 0;
    top: 50%;
    transform: translateY(3rem);
    opacity: 0;
    font-size: var(--size-body); 
    font-weight: 300;
    line-height: var(--lh-normal);
    letter-spacing: var(--ls-tight);
    text-align: center;
    transition: all 1.2s cubic-bezier(0.16, 1, 0.3, 1);
    pointer-events: none;
}

.message-item span {
    font-weight: 700;
    color: var(--color-point);
    text-decoration: none;
    border-bottom: 1px solid var(--color-point);
    padding-bottom: 2px;
}

.message-item.active {
    opacity: 1;
    transform: translateY(-50%);
    animation: fadeOutUp 1.5s ease-in forwards 4.5s;
}

@keyframes fadeOutUp {
    to {
        opacity: 0;
        transform: translateY(-150%);
    }
}

#final-choice-area {
    position: absolute;
    bottom: 15vh;
    display: flex;
    gap: 1.5rem;
    opacity: 0;
    transition: opacity 1s ease;
}

#final-choice-area.fade-in {
    opacity: 1;
}

#final-choice-area button {
    background: transparent !important;
    border: 1px solid var(--op-low);
    color: var(--op-mid);
    padding: 0.8rem 1.5rem;
    font-size: var(--size-meta);
    font-family: var(--font-data);
    font-weight: 500;
    letter-spacing: var(--ls-normal);
    cursor: pointer;
    text-transform: uppercase;
    transition: all 0.3s ease;
}

#final-choice-area button:hover {
    border-color: var(--color-point);
    color: var(--color-point);
    background-color: var(--op-ghost) !important;
}

#recall-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
    padding: 5rem 2.5rem;
    background-color: rgba(13, 16, 19, 0.98);
    display: flex;
    justify-content: center;
    overflow-y: auto;
}

.recall-content {
    max-width: 800px;
    width: 100%;
}

.recall-content h2 {
    font-size: var(--size-meta);
    font-family: var(--font-data);
    letter-spacing: var(--ls-wide);
    margin-bottom: 3rem;
    text-align: center;
    color: var(--color-point);
}

.recall-content hr {
    border: 0;
    border-top: 1px solid var(--color-border);
    margin: 40px 0;
}

#trace-sentence-result {
    font-size: var(--size-meta);
    font-family: var(--font-data);
    font-weight: 300;
    line-height: 1.2;
    color: var(--op-mid);
    text-align: left;
    word-break: break-all;
    white-space: pre-wrap;
}

#btn-back-to-choice {
    display: block;
    margin: 60px auto 0;
    background: var(--color-text);
    color: var(--color-bg);
    border: none;
    font-size: var(--size-meta);
    font-family: var(--font-data);
    letter-spacing: var(--ls-normal);
    padding: 0.6rem 2.5rem;
    font-weight: 700;
    cursor: pointer;
    transition: opacity 0.2s ease;
}

#btn-back-to-choice:hover {
    opacity: 0.8;
}

.hidden {
    display: none !important;
}