:root {
    --accent-color: #10b981;
    --bg-neutral: #fafafa;
    /* Neutral 50 */
    --text-muted: #737373;
    /* Neutral 500 */
}

body {
    font-family: 'Inter', sans-serif;
    color: #262626;
    /* Neutral 800 */
    line-height: 1.8;
    background-color: #fff;
}

.article-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 4rem 1.5rem;
}

h1,
h2,
h3,
h4 {
    font-family: 'Playfair Display', serif;
    color: #171717;
    /* Neutral 900 */
    line-height: 1.3;
}

h1 {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

h2 {
    font-size: 2.25rem;
    margin-top: 4rem;
    margin-bottom: 1.5rem;
    border-bottom: 2px solid #f5f5f5;
    /* Neutral 100 */
    padding-bottom: 0.5rem;
}

h3 {
    font-size: 1.75rem;
    margin-top: 3rem;
    margin-bottom: 1.25rem;
    color: #404040;
    /* Neutral 700 */
}

h4 {
    font-size: 1.25rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.meta {
    font-size: 0.9rem;
    color: #737373;
    /* Neutral 500 */
    margin-bottom: 3rem;
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    border-bottom: 1px solid #f5f5f5;
    /* Neutral 100 */
    padding-bottom: 1rem;
}

.meta b {
    color: #171717;
}

.spoiler-box {
    background: #fffbeb;
    border-left: 4px solid #f59e0b;
    padding: 1.5rem;
    margin: 2.5rem 0;
    font-style: italic;
    border-radius: 0 0.5rem 0.5rem 0;
}

.word-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
    margin-top: 1rem;
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid #f5f5f5;
}

.word-tag {
    background: #f5f5f5;
    /* Neutral 100 */
    padding: 0.4rem 0.8rem;
    border-radius: 0.4rem;
    font-weight: 700;
    font-size: 0.85rem;
    color: #404040;
    /* Neutral 700 */
    border: 1px solid #e5e5e5;
    /* Neutral 200 */
}

.bonus-section {
    background: #fafafa;
    /* Neutral 50 */
    border-radius: 1.5rem;
    padding: 3rem;
    margin: 4rem 0;
    border: 1px solid #f5f5f5;
    /* Neutral 100 */
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 2.5rem 0;
    font-size: 0.95rem;
}

th,
td {
    text-align: left;
    padding: 1.25rem;
    border-bottom: 1px solid #f5f5f5;
}

th {
    background: #fafafa;
    font-weight: 800;
    color: #525252;
    /* Neutral 600 */
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.difficulty-bar {
    background: #e3e3e3;
    height: 12px;
    border-radius: 6px;
    margin: 1rem 0;
    overflow: hidden;
}

.difficulty-fill {
    background: var(--accent-color);
    height: 100%;
}

.accordion-item {
    border: 1px solid #f5f5f5;
    border-radius: 0.75rem;
    margin-bottom: 0.75rem;
    overflow: hidden;
}

.accordion-header {
    width: 100%;
    padding: 1.25rem 1.5rem;
    text-align: left;
    background: white;
    border: none;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.2s;
}

.accordion-header:hover {
    background: #fafafa;
}

.accordion-content {
    display: none;
    padding: 2rem;
    border-top: 1px solid #f5f5f5;
    background: #fafafa;
}

.accordion-content.active {
    display: block;
}

.hint-box {
    background: #f0fdf4;
    border-radius: 1rem;
    padding: 2.5rem;
    margin: 2.5rem 0;
    border: 1px solid #dcfce7;
}

.hint-item {
    margin-bottom: 2rem;
}

.hint-item:last-child {
    margin-bottom: 0;
}

.hint-item b {
    color: #065f46;
    display: block;
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.faq-box {
    margin-top: 4rem;
}

.faq-item {
    margin-bottom: 2.5rem;
}

.faq-item b {
    display: block;
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
    color: #171717;
}

footer {
    margin-top: 6rem;
    padding: 5rem 0;
    background: #171717;
    /* Neutral 900 */
    color: #a3a3a3;
    /* Neutral 400 */
}

.footer-logo {
    font-weight: 800;
    color: #fff;
    font-size: 1.5rem;
    text-decoration: none;
    display: block;
    margin-bottom: 2rem;
}
/* Footer Responsive Layout Utilities */
.max-w-6xl { max-width: 1152px; }
.mx-auto { margin-left: auto; margin-right: auto; }
.px-6 { padding-left: 1.5rem; padding-right: 1.5rem; }
.mb-20 { margin-bottom: 5rem; }
.text-left { text-align: left; }

/* Column Logic */
.columns-1 { column-count: 1; }
@media (min-width: 768px) { .md\:columns-2 { column-count: 2; } }
@media (min-width: 1024px) { .lg\:columns-3 { column-count: 3; } }
.gap-12 { column-gap: 3rem; }

/* Themed Footer Links */
footer div[class*="columns-"] a {
    display: block;
    margin-bottom: 0.85rem;
    font-size: 14px;
    font-weight: 500;
    color: #525252;
    text-decoration: none;
    transition: all 0.2s ease;
    break-inside: avoid;
    line-height: 1.5;
}

footer div[class*="columns-"] a:hover {
    color: var(--accent-color);
    transform: translateX(5px);
}