* {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 2rem 5rem;
    margin-inline: auto;
    font-family:
        system-ui,
        -apple-system,
        BlinkMacSystemFont,
        "Inter",
        "Segoe UI",
        sans-serif;
    color: #222;
    background-color: #fafafa;
}

.site-header {
    margin-bottom: 2rem;
}

.layout {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

input[type="text"],
textarea,
.output-box {
    width: 100%;
    padding: 0.6rem 0.7rem;
    font-family: inherit;
    font-size: 1rem;
    border: 1px solid #ccc;
    border-radius: 6px;
    background: #fff;
}

textarea {
    resize: vertical;
}

.token-grid {
    display: grid;
    grid-auto-flow: column;
    grid-auto-columns: 1ch;
    grid-template-rows: auto auto;
    row-gap: 0.5rem;
    overflow-x: auto;
    padding: 0.5rem 0;
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 1.05rem;
    white-space: nowrap;
}

.char {
    grid-row: 1;
    text-align: center;
}

.char.new-line {
    background: #eef2f6;
    color: #4a6fa5;
    border-radius: 4px;
}

.token {
    grid-row: 2;
    background: #7aa6bf;
    border: 1px solid #5c5c5c;
    border-radius: 4px;
    font-size: 0.7rem;
    text-align: center;
    padding: 0.15rem 0.25rem;
    overflow: hidden;
    text-overflow: ellipsis;
}

.node {
    border-radius: 4px;
    font-size: 0.7rem;
    padding: 0.15rem 0.35rem;
    text-align: center;
    overflow: hidden;
    text-overflow: ellipsis;
    border: 1px solid #5c5c5c;
}

.random-btn {
    margin-top: 0.6rem;
    padding: 0.4rem 0.9rem;
    font-size: 0.9rem;
    background: #f4f4f4;
    border: 1px solid #ccc;
    border-radius: 6px;
    cursor: pointer;
}

.random-btn:hover {
    background: #eaeaea;
}

.error-underline {
    border-bottom: 3px solid #d93025;
}

.error-message {
    color: #d93025;
    font-size: 0.8rem;
    padding-top: 0.15rem;
    white-space: pre-wrap;
}