:root {
    --bg: #f5f6f8;
    --card: #ffffff;
    --text: #1f2933;
    --muted: #667085;
    --primary: #2f6f5e;
    --primary-dark: #245748;
    --border: #e2e6ea;
    --warning-bg: #fff7e6;
    --warning-border: #f0b429;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: var(--bg);
    color: var(--text);
}

a {
    color: var(--primary);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.topbar {
    background: linear-gradient(135deg, #2f6f5e, #1f3f37);
    color: white;
    padding: 36px 40px;
}

.topbar h1 {
    margin: 0 0 8px;
    font-size: 30px;
}

.topbar p {
    margin: 0;
    color: #d8eee8;
}

.back-link {
    display: inline-block;
    margin-bottom: 18px;
    color: white;
}

.layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 28px;
    padding: 28px 40px;
}

.sidebar {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 20px;
    height: fit-content;
    position: sticky;
    top: 24px;
}

.sidebar h2 {
    margin-top: 0;
    font-size: 18px;
}

.category-link {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 11px 12px;
    margin-bottom: 6px;
    border-radius: 10px;
    color: var(--text);
}

.category-link:hover,
.category-link.active {
    background: #e9f4f0;
    color: var(--primary-dark);
    text-decoration: none;
}

.category-link small {
    background: #eef1f3;
    border-radius: 20px;
    padding: 2px 8px;
    color: var(--muted);
}

.search-box {
    display: flex;
    gap: 10px;
    margin-bottom: 24px;
}

.search-box input {
    flex: 1;
    padding: 14px 16px;
    border: 1px solid var(--border);
    border-radius: 12px;
    font-size: 15px;
}

.search-box button {
    border: 0;
    background: var(--primary);
    color: white;
    padding: 0 20px;
    border-radius: 12px;
    cursor: pointer;
    font-weight: bold;
}

.search-box button:hover {
    background: var(--primary-dark);
}

.reset-link {
    align-self: center;
    color: var(--muted);
}

.section-heading {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 18px;
}

.section-heading h2 {
    margin: 0;
}

.section-heading p {
    color: var(--muted);
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
}

.card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 20px;
}

.card.important {
    border-color: var(--warning-border);
    background: var(--warning-bg);
}

.card-meta {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 12px;
    color: var(--muted);
    font-size: 13px;
}

.card-meta strong {
    color: #8a5a00;
}

.card h3 {
    margin: 0 0 10px;
    font-size: 20px;
}

.card p {
    color: var(--muted);
    line-height: 1.55;
}

.read-more {
    display: inline-block;
    margin-top: 10px;
    font-weight: bold;
}

.empty {
    background: var(--card);
    border: 1px solid var(--border);
    padding: 30px;
    border-radius: 14px;
    color: var(--muted);
}

.article-container {
    max-width: 900px;
    margin: 30px auto;
    padding: 0 24px;
}

.alert {
    background: var(--warning-bg);
    border: 1px solid var(--warning-border);
    border-radius: 12px;
    padding: 14px 18px;
    margin-bottom: 18px;
}

.article-content {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 28px;
    line-height: 1.75;
    font-size: 17px;
}

.keywords {
    margin-top: 16px;
    color: var(--muted);
}

@media (max-width: 900px) {
    .layout {
        grid-template-columns: 1fr;
        padding: 22px;
    }

    .sidebar {
        position: static;
    }

    .articles-grid {
        grid-template-columns: 1fr;
    }

    .search-box {
        flex-direction: column;
    }

    .search-box button {
        padding: 14px;
    }
}