/* Soft Sensor Toolbox — landing page. Static, no build step. */
:root {
  --ink: #0b1c2c;
  --ink-2: #10314a;
  --teal: #2ec4b6;
  --teal-dark: #159a8d;
  --amber: #d4a535;
  --paper: #f6f9fb;
  --card: #ffffff;
  --line: #dce6ee;
  --muted: #5b7186;
  --muted-dark: #9db4c6;
  --radius: 18px;
  --shadow: 0 24px 60px rgba(7, 38, 58, 0.16);
  --font: "Sora", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, monospace;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; font-family: var(--font); color: var(--ink); background: var(--paper); line-height: 1.6; -webkit-font-smoothing: antialiased; }
a { color: inherit; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip-link { position: absolute; left: 16px; top: -60px; z-index: 50; background: var(--ink); color: #fff; padding: 10px 16px; border-radius: 10px; transition: top .2s; }
.skip-link:focus { top: 12px; }
.container { width: min(1160px, calc(100% - 40px)); margin: 0 auto; }
.container.narrow { width: min(840px, calc(100% - 40px)); }

/* Header */
.site-header { position: sticky; top: 0; z-index: 40; background: rgba(246, 249, 251, .9); backdrop-filter: blur(12px); border-bottom: 1px solid var(--line); }
.header-inner { display: flex; align-items: center; gap: 28px; min-height: 72px; }
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; font-weight: 600; letter-spacing: -.01em; }
.brand strong { font-weight: 800; }
.brand-mark { display: inline-flex; }
.site-nav { display: flex; gap: 26px; margin-left: auto; }
.site-nav a { text-decoration: none; font-size: .94rem; font-weight: 500; color: #33506a; }
.site-nav a:hover { color: var(--teal-dark); }
.header-cta { display: flex; gap: 10px; align-items: center; }
.nav-toggle { display: none; margin-left: auto; width: 42px; height: 42px; border: 1px solid var(--line); background: #fff; border-radius: 10px; cursor: pointer; padding: 10px; }
.nav-toggle span:not(.sr-only) { display: block; height: 2px; background: var(--ink); margin: 5px 0; border-radius: 2px; }

.btn { display: inline-flex; align-items: center; gap: 8px; text-decoration: none; font-weight: 600; border-radius: 12px; padding: 10px 18px; font-size: .95rem; border: 1px solid transparent; transition: transform .15s ease, box-shadow .15s ease, background .15s ease; white-space: nowrap; }
.btn-lg { padding: 14px 24px; font-size: 1rem; border-radius: 14px; }
.btn-primary { background: var(--teal); color: #052a3d; box-shadow: 0 10px 26px rgba(46, 196, 182, .35); }
.btn-primary:hover { background: #45d3c5; transform: translateY(-1px); }
.btn-ghost { border-color: var(--line); background: #fff; color: #33506a; }
.btn-ghost:hover { border-color: #b9cfdd; }
.btn-outline { border-color: rgba(255,255,255,.45); color: #fff; background: rgba(255,255,255,.06); }
.btn-outline:hover { background: rgba(255,255,255,.14); }

/* Hero */
.hero { position: relative; overflow: hidden; background: linear-gradient(155deg, #071626 0%, #0b2438 48%, #0d3049 100%); color: #eaf4f9; }
.hero-bg { position: absolute; inset: 0; background: radial-gradient(700px 340px at 12% 0%, rgba(46,196,182,.28), transparent 60%), radial-gradient(640px 320px at 88% 8%, rgba(212,165,53,.16), transparent 55%), radial-gradient(900px 500px at 70% 110%, rgba(46,196,182,.12), transparent 60%); pointer-events: none; }
.hero-grid { position: relative; display: grid; grid-template-columns: 1.02fr 1.1fr; gap: 52px; padding: 84px 0 30px; align-items: center; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; font-family: var(--mono); font-size: .72rem; letter-spacing: .14em; text-transform: uppercase; color: var(--teal); margin: 0 0 18px; font-weight: 600; }
.eyebrow-dark { color: var(--teal-dark); }
.eyebrow-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--teal); box-shadow: 0 0 0 5px rgba(46,196,182,.18); }
.hero h1 { font-size: clamp(2.3rem, 4.6vw, 3.6rem); line-height: 1.08; letter-spacing: -.02em; margin: 0 0 20px; font-weight: 800; }
.hero h1 em { font-style: normal; color: var(--teal); }
.hero-lede { font-size: 1.13rem; color: #c3d7e4; margin: 0 0 30px; max-width: 34rem; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 26px; }
.hero-points { list-style: none; display: flex; flex-wrap: wrap; gap: 8px 22px; padding: 0; margin: 0; color: #a9c2d2; font-size: .92rem; }
.hero-points li::before { content: "✓"; color: var(--teal); font-weight: 700; margin-right: 8px; }

.hero-visual { position: relative; }
.app-window { background: #0a1f31; border: 1px solid rgba(157, 180, 198, .25); border-radius: 20px; box-shadow: var(--shadow); overflow: hidden; }
.app-window-bar { display: flex; align-items: center; gap: 14px; padding: 12px 16px; border-bottom: 1px solid rgba(157,180,198,.18); background: rgba(255,255,255,.03); }
.win-dots { display: inline-flex; gap: 6px; }
.win-dots i { width: 10px; height: 10px; border-radius: 50%; background: #33506a; }
.win-dots i:first-child { background: #e4572e; } .win-dots i:nth-child(2) { background: var(--amber); } .win-dots i:nth-child(3) { background: var(--teal); }
.win-title { font-family: var(--mono); font-size: .72rem; color: var(--muted-dark); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.win-live { margin-left: auto; display: inline-flex; align-items: center; gap: 7px; font-family: var(--mono); font-size: .7rem; letter-spacing: .08em; text-transform: uppercase; color: var(--teal); }
.pulse { width: 8px; height: 8px; border-radius: 50%; background: var(--teal); animation: pulse 1.8s infinite; }
@keyframes pulse { 0% { box-shadow: 0 0 0 0 rgba(46,196,182,.5);} 70% { box-shadow: 0 0 0 8px transparent;} 100% { box-shadow: 0 0 0 0 transparent;} }
.app-window-body { display: grid; grid-template-columns: 118px 1fr; min-height: 330px; }
.app-steps { display: flex; flex-direction: column; gap: 6px; padding: 16px 12px; border-right: 1px solid rgba(157,180,198,.16); }
.app-step { font-size: .78rem; font-weight: 600; color: var(--muted-dark); padding: 8px 10px; border-radius: 9px; }
.app-step.done { color: #d8e9f2; }
.app-step.done::before { content: "✓ "; color: var(--teal); }
.app-step.active { background: rgba(46,196,182,.14); color: #fff; box-shadow: inset 0 0 0 1px rgba(46,196,182,.35); }
.app-main-preview { padding: 16px; display: flex; flex-direction: column; gap: 12px; }
.kpi-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.kpi { background: rgba(255,255,255,.04); border: 1px solid rgba(157,180,198,.16); border-radius: 12px; padding: 10px 12px; display: flex; flex-direction: column; gap: 1px; }
.kpi-label { font-family: var(--mono); font-size: .62rem; letter-spacing: .1em; text-transform: uppercase; color: var(--muted-dark); }
.kpi strong { font-size: 1.25rem; letter-spacing: -.01em; }
.kpi strong.teal { color: var(--teal); }
.kpi-sub { font-size: .7rem; color: var(--muted-dark); }
.chart-card { background: rgba(255,255,255,.03); border: 1px solid rgba(157,180,198,.16); border-radius: 12px; padding: 12px 14px 6px; }
.chart-head { display: flex; justify-content: space-between; gap: 10px; font-size: .78rem; font-weight: 600; color: #d8e9f2; margin-bottom: 4px; }
.chart-legend { font-family: var(--mono); font-size: .66rem; color: var(--muted-dark); display: inline-flex; align-items: center; gap: 6px; }
.chart-legend i { width: 9px; height: 9px; border-radius: 50%; display: inline-block; }
.lg-lab { background: var(--amber); } .lg-est { background: var(--teal); }
.chart { width: 100%; height: auto; display: block; }
.chart-grid path { stroke: rgba(157,180,198,.16); stroke-width: 1; fill: none; }
.chart-band { fill: rgba(46,196,182,.13); }
.chart-est { fill: none; stroke: var(--teal); stroke-width: 3; stroke-linecap: round; }
.chart-points circle { fill: var(--amber); stroke: #0a1f31; stroke-width: 1.6; }
.equation { margin: 0; font-family: var(--mono); font-size: .78rem; color: #cfe6da; background: rgba(46,196,182,.08); border: 1px solid rgba(46,196,182,.22); border-radius: 10px; padding: 9px 12px; overflow-wrap: anywhere; }
.equation span { color: var(--teal); font-weight: 600; }
.hero-card { position: absolute; background: #fff; color: var(--ink); border-radius: 14px; box-shadow: 0 18px 44px rgba(3, 20, 32, .35); padding: 12px 16px; display: flex; flex-direction: column; max-width: 230px; }
.hero-card strong { font-size: .86rem; }
.hero-card span { font-size: .76rem; color: var(--muted); line-height: 1.45; }
.hero-card-a { left: -26px; bottom: 34px; }
.hero-card-b { right: -14px; top: 26px; }
.industry-strip { position: relative; margin: 46px 0 0; padding: 22px 0 30px; border-top: 1px solid rgba(157,180,198,.18); display: flex; flex-wrap: wrap; gap: 12px 28px; align-items: center; }
.industry-strip > span { font-family: var(--mono); font-size: .7rem; letter-spacing: .12em; text-transform: uppercase; color: var(--muted-dark); }
.industry-strip ul { list-style: none; display: flex; flex-wrap: wrap; gap: 8px 20px; margin: 0; padding: 0; font-weight: 600; font-size: .92rem; color: #d8e9f2; }

/* Sections */
.section { padding: 92px 0; }
.section-light { background: #fff; }
.section-dark { background: linear-gradient(160deg, #081a2a, #0c2a42); color: #eaf4f9; }
.section-head { max-width: 720px; margin-bottom: 44px; }
.section-head h2 { font-size: clamp(1.7rem, 3.2vw, 2.45rem); line-height: 1.18; letter-spacing: -.02em; margin: 0 0 14px; font-weight: 800; }
.section-head p:not(.eyebrow) { color: var(--muted); font-size: 1.05rem; margin: 0; }
.section-dark .section-head p:not(.eyebrow) { color: var(--muted-dark); }

.problem-grid, .feature-grid, .use-grid { display: grid; gap: 18px; }
.problem-grid { grid-template-columns: repeat(3, 1fr); }
.feature-grid { grid-template-columns: repeat(3, 1fr); }
.use-grid { grid-template-columns: repeat(2, 1fr); }
.problem-card, .use-card { background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; }
.use-card { background: #fff; }
.problem-num { font-family: var(--mono); font-size: .78rem; color: var(--teal-dark); font-weight: 600; }
.problem-card h3, .use-card h3, .feature-card h3 { margin: 10px 0 8px; font-size: 1.08rem; letter-spacing: -.01em; }
.problem-card p, .use-card p, .feature-card p { margin: 0; color: var(--muted); font-size: .95rem; }
.section-dark .feature-card p { color: var(--muted-dark); }

.workflow { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; counter-reset: step; }
.workflow-step { display: flex; gap: 18px; background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; }
.workflow-num { flex: 0 0 auto; width: 42px; height: 42px; border-radius: 50%; background: var(--ink); color: #fff; display: grid; place-items: center; font-weight: 700; font-family: var(--mono); }
.workflow-step h3 { margin: 4px 0 8px; font-size: 1.08rem; }
.workflow-step p { margin: 0; color: var(--muted); font-size: .95rem; }

.feature-card { background: rgba(255,255,255,.045); border: 1px solid rgba(157,180,198,.2); border-radius: var(--radius); padding: 26px; }
.feature-icon { width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center; background: rgba(46,196,182,.14); color: var(--teal); font-size: 1.15rem; border: 1px solid rgba(46,196,182,.3); }
.deploy-panel { margin-top: 20px; display: grid; grid-template-columns: 1.1fr .9fr; gap: 34px; background: rgba(255,255,255,.045); border: 1px solid rgba(157,180,198,.2); border-radius: 22px; padding: 34px; }
.deploy-panel h3 { font-size: 1.5rem; margin: 0 0 12px; letter-spacing: -.01em; }
.deploy-panel p:not(.eyebrow) { color: var(--muted-dark); margin: 0; }
.deploy-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 10px; }
.deploy-list li { display: flex; flex-direction: column; padding: 13px 16px; border-radius: 12px; background: rgba(7, 30, 46, .55); border: 1px solid rgba(157,180,198,.16); }
.deploy-list strong { font-size: .95rem; }
.deploy-list span { font-size: .84rem; color: var(--muted-dark); }

/* FAQ */
.faq-list { display: flex; flex-direction: column; gap: 12px; }
.faq-item { background: #fff; border: 1px solid var(--line); border-radius: 14px; overflow: hidden; }
.faq-q { width: 100%; display: flex; justify-content: space-between; align-items: center; gap: 16px; text-align: left; background: none; border: none; cursor: pointer; font: inherit; font-weight: 600; font-size: 1rem; color: var(--ink); padding: 20px 22px; }
.faq-q span { color: var(--teal-dark); font-size: 1.3rem; line-height: 1; transition: transform .2s ease; }
.faq-item.open .faq-q span { transform: rotate(45deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .25s ease; }
.faq-a p { margin: 0; padding: 0 22px 20px; color: var(--muted); font-size: .95rem; }

/* CTA + footer */
.cta-section { background: linear-gradient(140deg, #0a2439, #0e3a52); color: #fff; padding: 72px 0; }
.cta-inner { display: flex; align-items: center; justify-content: space-between; gap: 34px; flex-wrap: wrap; }
.cta-inner h2 { font-size: clamp(1.6rem, 3vw, 2.3rem); margin: 0 0 10px; letter-spacing: -.02em; }
.cta-inner p:not(.eyebrow) { color: #b9cfdd; margin: 0; max-width: 36rem; }
.site-footer { background: #06141f; color: #c3d7e4; padding: 58px 0 0; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 34px; padding-bottom: 42px; }
.brand-footer { color: #fff; }
.footer-note { color: var(--muted-dark); font-size: .92rem; max-width: 19rem; }
.site-footer h4 { color: #fff; font-size: .85rem; letter-spacing: .06em; text-transform: uppercase; margin: 4px 0 14px; font-family: var(--mono); font-weight: 600; }
.site-footer nav { display: flex; flex-direction: column; gap: 9px; }
.site-footer nav a { color: #a9c2d2; text-decoration: none; font-size: .93rem; }
.site-footer nav a:hover { color: var(--teal); }
.footer-bottom { border-top: 1px solid rgba(157,180,198,.16); padding: 18px 0 24px; display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-family: var(--mono); font-size: .76rem; color: var(--muted-dark); }

/* Reveal */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity .6s ease, transform .6s ease; }
.reveal.visible { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } html { scroll-behavior: auto; } .pulse { animation: none; } }

/* Responsive */
@media (max-width: 1020px) {
  .hero-grid { grid-template-columns: 1fr; padding-top: 60px; }
  .hero-card-a { left: 8px; } .hero-card-b { right: 8px; }
  .feature-grid, .problem-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 760px) {
  .site-nav { display: none; position: absolute; top: 72px; left: 16px; right: 16px; background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 12px; flex-direction: column; gap: 4px; box-shadow: var(--shadow); }
  .site-nav.open { display: flex; }
  .site-nav a { padding: 10px 12px; }
  .nav-toggle { display: block; }
  .header-cta .btn-ghost { display: none; }
  .header-cta .btn { padding: 9px 13px; font-size: .86rem; }
  .workflow, .use-grid, .feature-grid, .problem-grid, .deploy-panel { grid-template-columns: 1fr; }
  .app-window-body { grid-template-columns: 1fr; }
  .app-steps { flex-direction: row; flex-wrap: wrap; border-right: none; border-bottom: 1px solid rgba(157,180,198,.16); }
  .hero-card { display: none; }
  .section { padding: 64px 0; }
  .footer-grid { grid-template-columns: 1fr; }
  .win-title { display: none; }
}