/* ==========================================================================
   Home / Landing — Gonit Ongon 2.0
   De-slopped: no stock illustration, no glass cards, no purple gradients.
   Bilingual typographic hero + code-drawn geometry figure (Three.js mount),
   crisp bordered feature tiles, solid slate call-to-action.
   Tokens come from design-system.css (via shared.css).
   ========================================================================== */

.container {
    max-width: var(--container);
    margin-inline: auto;
    padding-inline: var(--page-pad);
}

/* ---------------------------------------------------------------- HERO --- */
.hero {
    padding: clamp(2.5rem, 1.5rem + 5vw, 6rem) 0 clamp(2rem, 1rem + 4vw, 5rem);
}

.hero-container {
    max-width: var(--container);
    margin-inline: auto;
    padding-inline: var(--page-pad);
    display: grid;
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: center;
    gap: clamp(2rem, 1rem + 4vw, 4.5rem);
}

.hero-content { max-width: 36rem; }

/* Bilingual headline — English set large, Bangla as the warm second voice */
.hero-content h1 {
    font-size: var(--text-5xl);
    font-weight: var(--weight-black);
    line-height: var(--leading-tight);
    letter-spacing: var(--tracking-display);
    color: var(--color-ink);
    margin-bottom: var(--space-3);
}
.hero-content h1 .hero-accent { color: var(--color-accent); }

.hero-content .hero-bangla {
    display: block;
    font-family: var(--font-bn);
    font-size: clamp(1.5rem, 1rem + 2.4vw, 2.25rem);
    font-weight: var(--weight-semibold);
    line-height: 1.25;
    color: var(--color-ink-2);
    letter-spacing: 0;
    margin-bottom: var(--space-5);
}

.hero-content p {
    font-size: var(--text-lg);
    line-height: var(--leading-normal);
    color: var(--color-ink-2);
    margin-bottom: var(--space-6);
    max-width: 34rem;
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-3);
}

.hero-buttons .btn { padding: 0.85rem 1.6rem; font-size: var(--text-lg); }

/* Trust line under the buttons — real, legible, no fake numbers */
.hero-meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2) var(--space-6);
    margin-top: var(--space-6);
    color: var(--color-muted);
    font-size: var(--text-sm);
}
.hero-meta span { display: inline-flex; align-items: center; gap: var(--space-2); }
.hero-meta i { color: var(--color-accent); }

/* ---- Hero figure: code-drawn geometry (also the Three.js/Manim mount) --- */
.hero-visual {
    position: relative;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    background:
        linear-gradient(180deg, var(--color-surface), var(--color-surface-2));
    padding: var(--space-5);
    min-height: 360px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}
/* subtle graph-paper grid — a field, not a decorative blob */
.hero-visual::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(to right, rgba(15, 23, 42, 0.04) 1px, transparent 1px),
        linear-gradient(to bottom, rgba(15, 23, 42, 0.04) 1px, transparent 1px);
    background-size: 28px 28px;
    mask-image: radial-gradient(ellipse at center, #000 55%, transparent 100%);
    pointer-events: none;
}
.hero-visual svg { position: relative; width: 100%; height: auto; max-width: 420px; }
.hero-visual .hero-figure-tag {
    position: absolute;
    left: var(--space-4);
    bottom: var(--space-4);
    font-size: var(--text-xs);
    font-weight: var(--weight-semibold);
    color: var(--color-muted);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    padding: 0.3rem 0.7rem;
}

/* Edge/stroke roles used by the inline SVG motif */
.geo-grid   { stroke: var(--color-border-strong); stroke-width: 1; }
.geo-edge   { stroke: var(--color-accent); stroke-width: 2.5; fill: none; stroke-linejoin: round; }
.geo-edge-2 { stroke: var(--slate-400); stroke-width: 1.5; fill: none; stroke-dasharray: 4 4; }
.geo-face   { fill: var(--color-accent); opacity: 0.08; }
.geo-curve  { stroke: var(--amber-600); stroke-width: 2.5; fill: none; }
.geo-dot    { fill: var(--color-accent); }
.geo-label  { fill: var(--color-ink-2); font: 600 13px var(--font-sans); }
.geo-formula{ fill: var(--amber-600); font: 700 13px var(--font-sans); }

.feature-bn {
    display: block;
    font-family: var(--font-bn);
    font-weight: var(--weight-semibold);
    font-size: var(--text-sm);
    color: var(--color-muted);
    margin-top: 2px;
    letter-spacing: 0;
}

/* ------------------------------------------------------------ FEATURES --- */
.features { padding: var(--section-gap) 0; }

.section-head { text-align: center; margin-bottom: clamp(2rem, 1rem + 3vw, 3.5rem); }
.section-title {
    font-size: var(--text-4xl);
    font-weight: var(--weight-bold);
    color: var(--color-ink);
    letter-spacing: var(--tracking-tight);
    margin-bottom: var(--space-3);
}
/* a filled brand tick — not a hairline rule */
.section-title::after {
    content: "";
    display: block;
    width: 52px;
    height: 4px;
    margin: var(--space-3) auto 0;
    background: var(--color-accent);
    border-radius: var(--radius-full);
}
.section-sub {
    max-width: 48ch;
    margin-inline: auto;
    color: var(--color-ink-2);
    font-size: var(--text-lg);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-5);
}

.feature-card {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    text-align: left;
    gap: var(--space-3);
    padding: var(--space-6);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    text-decoration: none;
    color: inherit;
    box-shadow: none;
    transition: transform var(--dur) var(--ease-spring),
                box-shadow var(--dur) var(--ease-standard),
                border-color var(--dur) var(--ease-standard);
}
.feature-card:hover {
    transform: translateY(-3px);
    border-color: var(--color-accent);
    box-shadow: var(--shadow-pop);
}

.feature-icon {
    width: 48px;
    height: 48px;
    display: grid;
    place-items: center;
    border-radius: var(--radius-md);
    background: var(--color-accent-soft);
    color: var(--color-accent-active);
    font-size: 1.35rem;
    box-shadow: none;
}
.feature-card:hover .feature-icon { transform: none; }

.feature-card h3 {
    font-size: var(--text-xl);
    font-weight: var(--weight-bold);
    color: var(--color-ink);
    margin: 0;
}
.feature-card p {
    color: var(--color-ink-2);
    font-size: var(--text-base);
    line-height: var(--leading-normal);
    margin: 0;
}
.feature-link {
    margin-top: auto;
    padding-top: var(--space-2);
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    font-weight: var(--weight-semibold);
    color: var(--color-accent);
    font-size: var(--text-sm);
}
.feature-card:hover .feature-link i { transform: translateX(3px); }
.feature-link i { transition: transform var(--dur) var(--ease-spring); }

/* ----------------------------------------------------------------- CTA --- */
.cta {
    margin: var(--section-gap) var(--page-pad) 0;
    border-radius: var(--radius-2xl);
    background: var(--color-header);
    color: var(--white);
    padding: clamp(2.5rem, 1.5rem + 4vw, 4.5rem) var(--page-pad);
    text-align: center;
    overflow: hidden;
}
.cta::before { display: none; }
.cta h2 {
    font-size: var(--text-4xl);
    font-weight: var(--weight-bold);
    color: var(--white);
    letter-spacing: var(--tracking-tight);
    margin-bottom: var(--space-3);
}
.cta p {
    font-size: var(--text-lg);
    color: var(--slate-300);
    max-width: 52ch;
    margin: 0 auto var(--space-6);
}

/* ---------------------------------------------------------- RESPONSIVE --- */
@media (max-width: 992px) {
    .hero-container { grid-template-columns: 1fr; }
    .hero-visual { order: -1; min-height: 280px; }
    .features-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .hero-content { max-width: none; }
    .hero-buttons .btn { flex: 1 1 auto; }
}

@media (max-width: 560px) {
    .features-grid { grid-template-columns: 1fr; }
    .cta { margin-inline: var(--space-3); }
}