/* ==========================================================================
   Ultra-Light Clean CSS Framework for Nubexis
   ========================================================================== */
:root {
    /* Colors - High Contrast, Accessible */
    --c-primary: #0f172a;      /* Slate-900 */
    --c-secondary: #2563eb;    /* Blue-600 */
    --c-secondary-alt: #1d4ed8;/* Blue-700 */
    --c-text: #1e293b;         /* Slate-800 - improved readability */
    --c-text-light: #475569;   /* Slate-600 - improved readability */
    --c-bg: #ffffff;
    --c-bg-light: #f8fafc;     /* Slate-50 */
    --c-border: #e2e8f0;       /* Slate-200 */

    /* Typography */
    --font-stack: 'Inter', system-ui, -apple-system, sans-serif;
    --fw-normal: 400; --fw-md: 500; --fw-bold: 700; --fw-black: 800;

    /* Spacing & Utilities */
    --space-md: 1.5rem;
    --space-lg: 3rem;
    --space-xl: 5rem;
    --radius-sm: 0.375rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 10px 15px -3px rgba(0,0,0,0.1);
    --transition: border-color 0.2s, background-color 0.2s, color 0.2s, box-shadow 0.2s;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body { margin: 0; font-family: var(--font-stack); color: var(--c-text); background: var(--c-bg); line-height: 1.6; -webkit-font-smoothing: antialiased; }

h1,h2,h3,h4,strong,.brand { color: var(--c-primary); font-weight: var(--fw-bold); margin: 0 0 1rem; line-height: 1.2; letter-spacing: -0.02em; }
h1 { font-size: clamp(2.5rem, 5vw, 4rem); font-weight: var(--fw-black); }
h2 { font-size: clamp(2rem, 3.5vw, 2.5rem); }
h3 { font-size: 1.25rem; }
p { margin: 0 0 1.25rem; }
a { color: var(--c-secondary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--c-secondary-alt); }
ul { margin: 0; padding: 0; list-style: none; }
img, svg { max-width: 100%; display: block; }

/* ==========================================================================
   Layout structure & Utilities
   ========================================================================== */
.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; }
.bg-light { background-color: var(--c-bg-light); }
.bg-dark { background-color: var(--c-primary); color: #f1f5f9; }
.bg-dark h2, .bg-dark strong, .light-text h2 { color: #ffffff; }

section { padding: var(--space-xl) 0; }
.section-title { text-align: center; max-width: 600px; margin: 0 auto var(--space-lg); }
.section-title p { color: var(--c-text-light); font-size: 1.125rem; }

/* Minimal Grids */
.grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: var(--space-lg); }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: var(--space-md); }

/* Buttons */
.btn { display: inline-flex; justify-content: center; align-items: center; padding: 0.75rem 1.5rem; font-weight: var(--fw-md); font-size: 1rem; border-radius: var(--radius-sm); border: 2px solid transparent; cursor: pointer; text-align: center; }
.btn-primary { background: var(--c-secondary); color: white; border-color: var(--c-secondary); }
.btn-primary:hover { background: var(--c-secondary-alt); border-color: var(--c-secondary-alt); color: white; }
.btn-secondary { background: white; color: var(--c-primary); border-color: var(--c-primary); }
.btn-secondary:hover { background: var(--c-bg-light); color: var(--c-primary); }
.btn-outline { background: transparent; color: var(--c-primary); border-color: var(--c-border); }
.btn-outline:hover { border-color: var(--c-primary); background: var(--c-bg-light); color: var(--c-primary); }
.btn-text { padding: 0; background: transparent; color: var(--c-secondary); font-weight: var(--fw-bold); }
.btn-text:hover { color: var(--c-secondary-alt); text-decoration: underline; }
.btn-large { padding: 1rem 2rem; font-size: 1.125rem; }
.btn-block { width: 100%; }

/* ==========================================================================
   Header Navbar
   ========================================================================== */
.site-header { position: fixed; top: 0; width: 100%; background: rgba(255,255,255,0.98); backdrop-filter: blur(8px); border-bottom: 1px solid transparent; z-index: 100; transition: border-color 0.3s; }
.site-header.scrolled { border-color: var(--c-border); box-shadow: var(--shadow-sm); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 4.5rem; }
.brand { font-size: 1.5rem; letter-spacing: -1px; }
.nav-menu { display: flex; align-items: center; gap: 2rem; }
.nav-list { display: flex; gap: 1.5rem; }
.nav-link { color: var(--c-text-light); font-weight: var(--fw-md); font-size: 0.95rem; }
.nav-link:hover { color: var(--c-primary); }
.nav-actions { display: flex; align-items: center; gap: 1rem; }
.login-link { font-weight: var(--fw-md); color: var(--c-text-light); font-size: 0.95rem; }
.login-link:hover { color: var(--c-primary); }
#nav-toggle { display: none; background: transparent; border: none; color: var(--c-primary); cursor: pointer; padding: 0.5rem; }

/* ==========================================================================
   Hero
   ========================================================================== */
.hero { padding: 8rem 0 5rem; background: linear-gradient(180deg, var(--c-bg-light) 0%, var(--c-bg) 100%); }
.hero-container { display: grid; grid-template-columns: 1fr 1fr; gap: 3rem; align-items: center; }
.hero-text p { font-size: 1.125rem; color: var(--c-text-light); margin-bottom: 2rem; max-width: 500px; }
.hero-cta { display: flex; gap: 1rem; flex-wrap: wrap; }

/* Abstract Minimal UI Dashboard (CSS Only) */
.abstract-dashboard { background: white; border: 1px solid var(--c-border); border-radius: var(--radius-md); box-shadow: var(--shadow-md); overflow: hidden; height: 380px; display: flex; flex-direction: column; }
.dash-bar { height: 3rem; background: var(--c-bg-light); border-bottom: 1px solid var(--c-border); }
.dash-grid { padding: 1.5rem; display: grid; gap: 1rem; flex: 1; grid-template-columns: 1fr 1fr; }
.dash-card { background: var(--c-bg-light); border-radius: var(--radius-sm); border: 1px solid var(--c-border); }
.dash-card.blue { background: rgba(37, 99, 235, 0.05); border-color: rgba(37, 99, 235, 0.2); }
.dash-card.long { grid-column: span 2; }

/* ==========================================================================
   Benefits & Modules
   ========================================================================== */
.benefit-card { padding: 1.5rem; border-radius: var(--radius-md); background: white; border: 1px solid var(--c-border); transition: var(--transition); }
.benefit-card:hover { border-color: var(--c-secondary); box-shadow: var(--shadow-sm); }
.benefit-card .icon { width: 3rem; height: 3rem; border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center; font-size: 1.5rem; margin-bottom: 1rem; }
.bg-blue-light { background: #e0e7ff; } .bg-green-light { background: #dcfce3; } .bg-purple-light { background: #f3e8ff; }

/* Use Case specific (forces dark text even inside bg-dark) */
.bg-dark .use-case-card { color: var(--c-text); background: white; }
.bg-dark .use-case-card p { color: var(--c-text-light); }
.bg-dark .use-case-card p strong { color: var(--c-primary); }

.module-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 2rem; }
.module-item { display: flex; border-bottom: 1px solid var(--c-border); padding-bottom: 2rem; }
.module-info h3 { margin-bottom: 0.5rem; }
.module-info p { color: var(--c-text-light); }

/* ==========================================================================
   Pricing
   ========================================================================== */
.pricing-grid { max-width: 900px; margin: 0 auto; align-items: center; }
.price-tier { background: white; border: 1px solid var(--c-border); border-radius: var(--radius-lg); padding: 3rem 2rem; display: flex; flex-direction: column; position: relative; }
.price-tier.popular { border-width: 2px; border-color: var(--c-secondary); box-shadow: var(--shadow-md); transform: scale(1.02); }
.badge { position: absolute; top: -14px; left: 50%; transform: translateX(-50%); background: var(--c-secondary); color: white; padding: 0.25rem 1rem; border-radius: 2rem; font-size: 0.8rem; font-weight: var(--fw-bold); text-transform: uppercase; letter-spacing: 0.05em; }
.tier-header { border-bottom: 1px solid var(--c-border); padding-bottom: 1.5rem; margin-bottom: 1.5rem; }
.price { font-size: 1rem; color: var(--c-text-light); }
.price span { font-size: 3rem; font-weight: var(--fw-black); color: var(--c-primary); letter-spacing: -1px; }
.tier-features { flex: 1; margin-bottom: 2rem; }
.tier-features li { padding-left: 1.5rem; margin-bottom: 1rem; position: relative; font-size: 0.95rem; }
.tier-features li::before { content: '✓'; position: absolute; left: 0; color: var(--c-secondary); font-weight: bold; }

/* ==========================================================================
   Testimonials & FAQ
   ========================================================================== */
.testimonial-card { padding: 2rem; background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1); border-radius: var(--radius-md); }
.testimonial-card blockquote { margin: 0 0 1.5rem; font-style: italic; font-size: 1.125rem; line-height: 1.5; color: #cbd5e1; }
.author strong { display: block; margin-bottom: 0; color: white; }
.author span { font-size: 0.85rem; color: #94a3b8; }

.accordion-list { max-width: 800px; margin: 0 auto; border-top: 1px solid var(--c-border); }
.accordion-item { border-bottom: 1px solid var(--c-border); }
.accordion-trigger { width: 100%; text-align: left; padding: 1.5rem 0; background: none; border: none; font-size: 1.125rem; font-weight: var(--fw-bold); color: var(--c-primary); font-family: inherit; cursor: pointer; display: flex; justify-content: space-between; align-items: center; }
.accordion-trigger::after { content: '+'; font-size: 1.5rem; color: var(--c-secondary); transition: transform 0.2s; }
.accordion-trigger[aria-expanded="true"]::after { transform: rotate(45deg); }
.accordion-content { max-height: 0; overflow: hidden; transition: max-height 0.3s ease; }
.accordion-content p { padding-bottom: 1.5rem; color: var(--c-text-light); }

/* ==========================================================================
   Contact Form B2B
   ========================================================================== */
.contact-box { background: white; border: 1px solid var(--c-border); border-radius: var(--radius-lg); padding: 3rem; display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; box-shadow: var(--shadow-md); }
.form-group { margin-bottom: 1.25rem; }
.form-group label { display: block; font-weight: var(--fw-md); margin-bottom: 0.5rem; font-size: 0.9rem; color: var(--c-primary); }
.lead-form input, .lead-form select { width: 100%; padding: 0.75rem 1rem; border: 1px solid var(--c-border); border-radius: var(--radius-sm); font-family: inherit; font-size: 1rem; color: var(--c-text); background: var(--c-bg-light); transition: var(--transition); }
.lead-form input:focus, .lead-form select:focus { outline: none; border-color: var(--c-secondary); background: white; box-shadow: 0 0 0 3px rgba(37,99,235,0.1); }
.error { color: #dc2626; font-size: 0.8rem; display: none; margin-top: 0.25rem; }
.form-group.invalid input, .form-group.invalid select { border-color: #dc2626; }
.form-group.invalid .error { display: block; }

.form-status { margin-top: 1rem; text-align: center; font-weight: var(--fw-md); font-size: 0.9rem; padding: 0.75rem; border-radius: var(--radius-sm); display: none; }
.form-status.success { background: #dcfce3; color: #166534; display: block; }

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer { border-top: 1px solid var(--c-border); padding: 4rem 0 2rem; background: var(--c-bg-light); }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 3rem; margin-bottom: 3rem; }
.footer-brand p { color: var(--c-text-light); font-size: 0.95rem; margin-top: 0.5rem; max-width: 250px; }
.footer-title { display: block; font-weight: var(--fw-bold); color: var(--c-primary); margin-bottom: 1.25rem; }
.footer-links li { margin-bottom: 0.75rem; }
.footer-links a { color: var(--c-text-light); font-size: 0.95rem; }
.footer-links a:hover { color: var(--c-secondary); }
.footer-copyright { border-top: 1px solid var(--c-border); padding-top: 1.5rem; text-align: center; color: var(--c-text-light); font-size: 0.85rem; }

/* ==========================================================================
   Responsive Mobile Logic
   ========================================================================== */
@media (max-width: 900px) {
    .contact-box, .hero-container { grid-template-columns: 1fr; }
    .hero { padding-top: 7rem; }
    .hero-text { text-align: center; }
    .hero-text p { margin: 0 auto 2rem; }
    .hero-cta { justify-content: center; }
    .price-tier.popular { transform: none; }
    .footer-grid { grid-template-columns: 1fr; gap: 2rem; }
}

@media (max-width: 768px) {
    #nav-toggle { display: block; }
    .nav-menu { position: absolute; top: 4.5rem; left: 0; width: 100%; background: white; border-bottom: 1px solid var(--c-border); padding: 1.5rem; flex-direction: column; gap: 1.5rem; align-items: flex-start; max-height: 0; overflow: hidden; transition: max-height 0.3s ease; opacity: 0; }
    .nav-menu[aria-hidden="false"] { max-height: 500px; opacity: 1; }
    .nav-list { flex-direction: column; gap: 1rem; width: 100%; }
    .nav-actions { width: 100%; flex-direction: column; align-items: stretch; }
    .login-link { padding-bottom: 1rem; text-align: center; }
}