/* ── Base layout ── */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    background: #f5f5f5;
    line-height: 1.6;
}

h1 { margin-bottom: 5px; }

h2 {
    color: #333;
    border-bottom: 2px solid #2ea2cc;
    padding-bottom: 5px;
    margin-top: 30px;
}

.subtitle {
    color: #666;
    margin-bottom: 20px;
    font-size: 1.1em;
}

.back-link {
    display: inline-block;
    margin-bottom: 20px;
    color: #2ea2cc;
    text-decoration: none;
}

.back-link:hover { text-decoration: underline; }

/* ── Content sections ── */
.feature-section {
    background: #fff;
    padding: 20px;
    margin-bottom: 20px;
    border-radius: 5px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.feature-section h3 {
    margin-top: 0;
    color: #2ea2cc;
}

ul { margin: 0; padding-left: 20px; }
li { margin-bottom: 8px; }

.cta {
    margin-top: 30px;
    padding: 20px;
    background: #e8f5e9;
    border-left: 4px solid #28a745;
    border-radius: 0 5px 5px 0;
}

.cta a { color: #2ea2cc; font-weight: bold; }

/* ── Banner close button ── */
#banner-wrap { position: relative; }

.banner-close {
    position: absolute;
    bottom: -12px;
    right: -12px;
    width: 26px;
    height: 26px;
    background: #fff;
    border: none;
    border-radius: 50%;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
    color: #333;
    font-size: 18px;
    line-height: 26px;
    text-align: center;
    cursor: pointer;
    z-index: 1002;
    padding: 0;
    transition: transform 0.2s, color 0.2s;
}

.banner-close:hover { color: #e74c3c; transform: scale(1.1); }

/* ── Dark mode toggle ── */
.dark-mode-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    padding: 5px;
    z-index: 1000;
}

.dark-mode-toggle:hover { opacity: 0.7; }

/* ── Dark mode ── */
body.dark-mode { background: #1a1a1a; color: #e0e0e0; }

body.dark-mode h1,
body.dark-mode h2 { color: #e0e0e0; border-bottom-color: #0073aa; }

body.dark-mode h3 { color: #4db8e8; }

body.dark-mode .subtitle { color: #b0b0b0; }

body.dark-mode .back-link { color: #4db8e8; }

body.dark-mode .feature-section {
    background: #2d2d2d;
    box-shadow: 0 1px 3px rgba(0,0,0,0.3);
}

body.dark-mode .cta { background: #2d4a2d; border-left-color: #4caf50; }

body.dark-mode .cta a { color: #4db8e8; }