* { margin: 0; padding: 0; box-sizing: border-box; }
html, body { width: 100%; }
body {
    font-family: Arial, Helvetica, sans-serif;
    background: #eceff1;
    color: #263238;
}
#app {
    max-width: 1000px;
    margin: 0 auto;
    padding: 16px 18px 24px;
}
.title {
    font-size: 24px;
    color: #1a3a6c;
    text-align: center;
    margin-bottom: 6px;
}
.subtitle {
    font-size: 13px;
    color: #546e7a;
    text-align: center;
    margin-bottom: 18px;
}
.cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}
@media (max-width: 720px) {
    .cards { grid-template-columns: 1fr; }
}
.card {
    background: #fff;
    border-radius: 12px;
    border-top: 6px solid var(--accent);
    box-shadow: 0 2px 8px rgba(0,0,0,0.10);
    padding: 16px 16px 18px;
    position: relative;
    transition: box-shadow 0.2s, transform 0.2s;
    overflow: hidden;
}
.card:hover {
    box-shadow: 0 6px 18px rgba(0,0,0,0.18);
    transform: translateY(-3px);
}
.card .icon {
    font-size: 34px;
    text-align: center;
    margin-bottom: 6px;
}
.card .warn {
    position: absolute;
    top: 12px;
    right: 14px;
    font-size: 18px;
}
.card h3 {
    font-size: 17px;
    color: var(--accent-dark);
    text-align: center;
    margin-bottom: 10px;
}
.card .label { font-size: 11px; font-weight: bold; color: #78909c; text-transform: uppercase; letter-spacing: 0.04em; }
.card .problem { font-size: 13.5px; margin: 2px 0 10px; }
.card .example {
    background: var(--accent-light);
    border-left: 4px solid var(--accent);
    border-radius: 4px;
    padding: 8px 10px;
    font-size: 12.5px;
    cursor: pointer;
    margin-bottom: 4px;
}
.card .example .ex-hint { font-size: 11px; color: var(--accent-dark); font-weight: bold; display: block; margin-top: 6px; }
.card .example .ex-detail {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
    font-size: 12px;
    color: #37474f;
}
.card .example.open .ex-detail { max-height: 260px; margin-top: 8px; }
.card .impact { font-size: 12.5px; margin-top: 10px; }
.card .impact .label { color: #b71c1c; }

/* Mitigation overlay revealed on hover */
.card .mitigation {
    margin-top: 12px;
    border-top: 1px dashed #cfd8dc;
    padding-top: 10px;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 0.3s ease, opacity 0.3s ease;
}
.card:hover .mitigation { max-height: 220px; opacity: 1; }
.card .mitigation .label { color: #2e7d32; }
.card .mitigation ul { margin: 6px 0 0 18px; font-size: 12.5px; }
.card .mitigation li { margin-bottom: 4px; }

.next-section {
    margin-top: 22px;
    background: linear-gradient(135deg, #4a148c, #6a1b9a);
    color: #fff;
    border-radius: 12px;
    padding: 18px 22px;
    text-align: center;
}
.next-section h2 { font-size: 19px; margin-bottom: 8px; }
.next-section p { font-size: 13.5px; line-height: 1.6; max-width: 760px; margin: 0 auto 12px; }
.next-arrow {
    display: inline-block;
    background: #fff;
    color: #4a148c;
    font-weight: bold;
    font-size: 13.5px;
    text-decoration: none;
    padding: 9px 18px;
    border-radius: 24px;
    transition: background 0.2s;
}
.next-arrow:hover { background: #f3e5f5; }