:root{
    --bg: #f4f7fb;
    --bg-alt: #ffffff;
    --card: #ffffff;
    --card-alt: #f8fbff;
    --text: #18202a;
    --muted: #5f6b7a;
    --border: #d9e2ec;
    --accent: #4ea1ff;
    --accent-hover: #7abaff;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

body.dark{
    --bg: #0f141a;
    --bg-alt: #151c24;
    --card: #1b2430;
    --card-alt: #202b38;
    --text: #e7edf5;
    --muted: #a7b4c3;
    --border: #2b3745;
    --accent: #67b3ff;
    --accent-hover: #94caff;
    --shadow: 0 14px 40px rgba(0, 0, 0, 0.35);
}

*{
    box-sizing: border-box;
}

html{
    scroll-behavior: smooth;
}

body{
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background:
        linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0)),
        var(--bg);
    color: var(--text);
    line-height: 1.5;
    transition: background 0.2s ease, color 0.2s ease;
}

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

a:hover{
    color: var(--accent-hover);
    text-decoration: underline;
}

.page{
    max-width: 1300px;
    margin: 0 auto;
    padding: 24px;
}

.topbar{
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 24px;
    padding: 20px 24px;
    background: linear-gradient(135deg, var(--card), var(--card-alt));
    border: 1px solid var(--border);
    border-radius: 18px;
    box-shadow: var(--shadow);
}

.title-wrap h1{
    margin: 0;
    font-size: 2rem;
    line-height: 1.1;
}

.title-wrap p{
    margin: 8px 0 0;
    color: var(--muted);
}

.theme-toggle{
    border: 1px solid var(--border);
    background: var(--bg-alt);
    color: var(--text);
    padding: 10px 14px;
    border-radius: 10px;
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: bold;
}

.theme-toggle:hover{
    border-color: var(--accent);
}

.grid{
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 18px;
}

.card{
    background: linear-gradient(180deg, var(--card), var(--card-alt));
    border: 1px solid var(--border);
    border-radius: 18px;
    padding: 18px 20px;
    box-shadow: var(--shadow);
}

.card h2{
    margin-top: 0;
    margin-bottom: 12px;
    font-size: 1.2rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 8px;
}

.card ul{
    margin: 0;
    padding-left: 18px;
}

.card li{
    margin-bottom: 10px;
}

.meta{
    color: var(--muted);
}

.single-column{
    margin-top: 18px;
    display: grid;
    gap: 18px;
}

.link-list{
    display: grid;
    gap: 8px;
}

.link-list .row{
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 12px;
    background: rgba(255,255,255,0.02);
}

.footer-note{
    margin-top: 22px;
    color: var(--muted);
    font-size: 0.9rem;
    text-align: center;
}

@media (max-width: 640px){
    .page{
        padding: 16px;
    }

    .topbar{
        padding: 16px;
    }

    .title-wrap h1{
        font-size: 1.6rem;
    }
}