/* ============================================================
   Layout — 栅格、容器、章节头
   ============================================================ */

.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--gutter);
}

.container-narrow {
    max-width: var(--container-narrow);
    margin: 0 auto;
    padding: 0 var(--gutter);
}

.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* Section Head (centered) */
.section-head {
    text-align: center;
    margin-bottom: 48px;
}
.section-head .section-kicker { margin-bottom: 12px; }
.section-head h2 {
    font-size: clamp(1.75rem, 3.5vw, 2.5rem);
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 14px;
    letter-spacing: -0.02em;
    line-height: 1.25;
}
.section-head h2 .gradient-text {
    background: linear-gradient(135deg, var(--primary-700), var(--primary-500));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.section-head p {
    font-size: 1rem;
    color: var(--gray-600);
    line-height: 1.7;
    max-width: 640px;
    margin: 0 auto;
}