@import url('https://fonts.googleapis.com/css2?family=Merriweather:wght@400;700&display=swap');
:root {
    --bg-color: #0f172a;
    --text-color: #e2e8f0;
    --secondary-text: #94a3b8;
    --card-bg: #1e293b;
    --accent: #7c3aed;
    --accent-color: #38bdf8;
    --accent-hover: #0ea5e9;
    --border-color: #334155;
    --header-bg: #1e293b;
    --footer-bg: #1e293b;
    --table-header-bg: #334155;
    --table-row-hover: #1e40af;
}

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

body {
    font-family: 'Merriweather', serif;
    background: var(--bg-color);
    color: var(--text-color);
    line-height: 1.5;
}

.container {
    max-width: 1200px;
    margin: auto;
    padding: 20px;
}

.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--header-bg);
    padding: 15px 20px;
    border-radius: 8px;
    margin-bottom: 20px;
    gap: 10px;
    flex-wrap: wrap;
}

.group {
    display: flex;
    flex-direction: row;
    gap: 10px;
    align-items: center;
    justify-content: space-between;
    width: 100%;
}

.group h1 {
    font-size: 2rem;
    color: var(--accent-color);
}

.badge {
    display: inline-block;
    padding: 6px 12px;
    border-radius: 999px;
    background: rgba(124, 58, 237, 0.12);
    color: var(--accent);
    font-weight: 600;
    font-size: 20px;
    letter-spacing: 0.3px;
}

.hint {
    font-size: 1.2rem;
    color: var(--secondary-text);
}

.welcome-message {
    margin-top: 30px;
    padding-left: 30px;
    font-size: 1rem;
    color: var(--accent-color);
    font-weight: 500;
    font-style: italic;
}

.btn {
    display: flex;
    flex-direction: row;
    gap: 10px;
    align-items: flex-start;
    justify-content: flex-start;
    width: 100%;
}

#toggle-btn {
    margin-left: 100px;
    padding: 8px 14px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    border: none;
    cursor: pointer;
    transition: background 0.3s;
}

#toggle-btn {
    background: var(--accent-color);
    color: #000;
}

#toggle-btn:hover {
    background: var(--accent-hover);
}

.grid {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    width: 100%;
}

.card {
    background: var(--card-bg);
    border-radius: 8px;
    padding: 20px;
    transition: opacity 0.4s ease, transform 0.4s ease;
    width: 90%;
    max-width: 1000px;
}

.card.hidden {
    display: none;
}

@media (min-width: 1024px) {
    .card {
        width: 80%;
        max-width: 1100px;
    }
}

.section-title {
    font-size: 1.2rem;
    color: var(--accent-color);
    margin-bottom: 15px;
    font-weight: 600;
}

.tree {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 15px;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    color: var(--text-color);
    white-space: pre;
    overflow-x: auto;
}

.table-wrap {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
}

thead {
    background: var(--table-header-bg);
}

thead th {
    padding: 10px;
    text-align: left;
    color: var(--accent-color);
}

tbody tr {
    border-bottom: 1px solid var(--border-color);
}

tbody tr:hover {
    background: var(--table-row-hover);
}

td {
    padding: 10px;
}

.syntax {
    color: var(--accent-color);
    font-family: monospace;
}

.footer {
    background: var(--footer-bg);
    padding: 10px;
    margin-top: 20px;
    border-radius: 6px;
    text-align: center;
    font-size: 0.85rem;
    color: var(--secondary-text);
}

@media (min-width: 768px) {
    .grid {
        grid-template-columns: 1fr 1fr;
        gap: 20px;
    }
}