/* ==========================================================================
   Layout: containers, section rhythm and tones, grids, section headers
   ========================================================================== */
.container { width: 100%; max-width: var(--container); margin-inline: auto; padding-inline: var(--gutter); }
.container--wide { max-width: var(--container-wide); }
.container--narrow { max-width: var(--container-narrow); }

.section { position: relative; padding-block: var(--section-y); }
.section--tight { padding-block: var(--section-y-tight); }
.section--light { background: transparent; }
.section--surface { background: var(--c-surface); }
.section--dark { background: var(--bg-deep); color: var(--c-text-inv); }
.section--dark h1, .section--dark h2, .section--dark h3, .section--dark h4 { color: var(--c-text-inv); }
.section--dark::before { /* faint engineering grid */
	content: ""; position: absolute; inset: 0; pointer-events: none;
	background-image: linear-gradient(var(--grid-line) 1px, transparent 1px), linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
	background-size: var(--grid-size) var(--grid-size);
	mask-image: linear-gradient(to bottom, rgba(0,0,0,.9), rgba(0,0,0,.25));
}
.section--dark > .container { position: relative; }
.section--narrow > .container { max-width: var(--container-narrow); }
.section--cta { padding-block: clamp(3.5rem, 2.5rem + 4vw, 6.5rem); }
.section + .section--light.section--tight { padding-top: 0; }

.section-header { max-width: 760px; margin-bottom: clamp(2rem, 1.5rem + 2vw, 3.5rem); }
.section-header--center { margin-inline: auto; text-align: center; }
.section-header--center .eyebrow::before { display: none; }
.section-header__title { margin-bottom: var(--sp-3); }
.section-header__lead { font-size: var(--fs-lg); color: var(--c-text-2); margin: 0; }
.section-header--row { display: flex; align-items: flex-end; justify-content: space-between; gap: var(--sp-6); max-width: none; flex-wrap: wrap; }
.section-header--row .section-header__lead { max-width: 60ch; }

.grid { display: grid; gap: clamp(1rem, .75rem + 1.2vw, 1.75rem); }
/* grid/flex children must be allowed to shrink below their content min-width (tables, long mono strings) */
.grid > *, .two-col > *, .split > *, .ind-panel > *, .cta-band > *, .hero__inner > *, .page-hero__inner > *, .cap-row > *, .challenge > *, .story__step > *, .contact-grid > *, .rfq-layout > * { min-width: 0; }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid--gap-lg { gap: clamp(1.5rem, 1rem + 2vw, 2.5rem); }
.split { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr); gap: clamp(2rem, 1.5rem + 3vw, 5rem); align-items: center; }
.split--reverse > :first-child { order: 2; }
.two-col { display: grid; grid-template-columns: minmax(0, 2fr) minmax(280px, 1fr); gap: clamp(2rem, 1.5rem + 2vw, 4rem); align-items: start; }
.stack-sm > * + * { margin-top: var(--sp-3); }
.stack-md > * + * { margin-top: var(--sp-6); }
.stack-lg > * + * { margin-top: var(--sp-10); }
.btn-row { display: flex; flex-wrap: wrap; gap: var(--sp-3); align-items: center; }
.text-center { text-align: center; }
.text-muted { color: var(--c-text-2); }

@media (max-width: 1024px) {
	.grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
	.grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
	.two-col { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
	.split { grid-template-columns: 1fr; }
	.split--reverse > :first-child { order: 0; }
	.grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr; }
	.section-header--row { align-items: flex-start; }
}