/* TCC site. The drawing is the hero: deep teal, paper white, one amber accent.
   Inter for words, Plex Mono only for chainages and small labels. 1px rules, no cards. */
:root {
  --deep: #0b2b32;
  --deep-2: #12393f;
  --deep-line: rgba(255, 255, 255, 0.16);
  --on-deep: #e8f0f0;
  --on-deep-2: #9db6b8;
  --ink: #102a2e;
  --ink-2: #4a6467;
  --line: #d6dfe0;
  --paper: #ffffff;
  --alt: #f3f6f6;
  --accent: #f0a23b;
  --accent-dark: #d98a22;
  --sans: Inter, "Segoe UI", system-ui, -apple-system, Arial, sans-serif;
  --mono: "IBM Plex Mono", Consolas, ui-monospace, monospace;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 17px/1.6 var(--sans); -webkit-font-smoothing: antialiased; }
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
code { font: 0.86em var(--mono); background: rgba(16, 42, 46, 0.07); padding: 0.05em 0.3em; }
h1, h2, h3 { margin: 0 0 0.5em; letter-spacing: -0.02em; }
h1 { font-size: clamp(2.3rem, 5.6vw, 4.6rem); line-height: 1.04; font-weight: 700; }
h2 { font-size: clamp(1.7rem, 3.2vw, 2.6rem); line-height: 1.1; font-weight: 700; }
h3 { font-size: 1.1rem; line-height: 1.3; font-weight: 600; letter-spacing: 0; }
p { margin: 0 0 1em; }

.wrap-wide { max-width: 1280px; margin: 0 auto; padding: 0 32px; }
.mono, .micro, .micro-dark { font-family: var(--mono); font-size: 0.75rem; font-weight: 500; letter-spacing: 0.08em; text-transform: uppercase; }
.micro { color: var(--on-deep-2); margin: 0 0 18px; }
.micro-dark { color: var(--ink-2); }

/* Header: a toolbar of thin boxes, like the app */
.site-header { position: sticky; top: 0; z-index: 10; background: var(--deep); color: var(--on-deep); border-bottom: 1px solid var(--deep-line); }
.header-row { display: flex; align-items: center; gap: 24px; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.brand-name { font-weight: 700; letter-spacing: 0.04em; }
.brand-sub { color: var(--on-deep-2); font-size: 0.9rem; }
.nav { display: flex; margin-left: auto; border: 1px solid var(--deep-line); }
.nav a { font: 500 0.72rem/1 var(--mono); letter-spacing: 0.08em; text-transform: uppercase; text-decoration: none; color: var(--on-deep-2); padding: 10px 14px; border-left: 1px solid var(--deep-line); }
.nav a:first-child { border-left: 0; }
.nav a:hover { color: #fff; background: var(--deep-2); }

.btn { display: inline-block; background: var(--accent); color: var(--deep); text-decoration: none; font-weight: 600; padding: 12px 22px; border: 1px solid var(--accent); }
.btn:hover { background: var(--accent-dark); border-color: var(--accent-dark); }
.btn-small { padding: 7px 14px; font-size: 0.88rem; }

/* Hero: one line, one button, the sheet */
.hero { background: var(--deep); color: var(--on-deep); padding: 72px 0 0; }
.hero h1 { color: #fff; }
.hero h1 .pair { color: var(--accent); } /* P6 and A3 read as a pair down the left edge */
.lede { color: var(--on-deep-2); font-size: 1.15rem; max-width: 560px; margin-bottom: 30px; }
.viewport { margin: 64px 0 0; }
.viewport-meta { display: flex; justify-content: space-between; gap: 16px; font: 500 0.72rem/1 var(--mono); letter-spacing: 0.08em; text-transform: uppercase; color: var(--on-deep-2); padding: 12px 0; }
/* Corner ticks around the sheet, drawn as eight 1px strokes */
.viewport-frame { --t: rgba(255, 255, 255, 0.55); padding: 14px; background:
  linear-gradient(var(--t), var(--t)) left top / 14px 1px, linear-gradient(var(--t), var(--t)) left top / 1px 14px,
  linear-gradient(var(--t), var(--t)) right top / 14px 1px, linear-gradient(var(--t), var(--t)) right top / 1px 14px,
  linear-gradient(var(--t), var(--t)) left bottom / 14px 1px, linear-gradient(var(--t), var(--t)) left bottom / 1px 14px,
  linear-gradient(var(--t), var(--t)) right bottom / 14px 1px, linear-gradient(var(--t), var(--t)) right bottom / 1px 14px;
  background-repeat: no-repeat; }
.viewport-frame img { background: #fff; }

/* Separable portions: four columns under the sheet, same order as its panels */
.portions { background: var(--deep); color: var(--on-deep); padding: 56px 0 88px; }
.portions-head { display: grid; grid-template-columns: 5fr 7fr; gap: 48px; align-items: start; margin-bottom: 44px; }
.portions-head h2 { color: #fff; margin: 0; }
.portions-head p { color: var(--on-deep-2); margin: 0; }
.sp-row { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--deep-line); }
.sp-row li { padding: 18px 24px 0 0; border-right: 1px solid var(--deep-line); margin-right: 24px; display: flex; flex-direction: column; gap: 4px; }
.sp-row li:last-child { border-right: 0; margin-right: 0; }
.sp-row .mono:first-child { color: var(--accent); }
.sp-row strong { color: #fff; font-weight: 600; font-size: 1.05rem; }
.sp-row .mono { color: var(--on-deep-2); }
.sp-row p { color: var(--on-deep-2); font-size: 0.95rem; margin: 8px 0 0; }

/* Chainage ruler as a section divider: major tick every 20%, minor every 4% */
.ruler { background: var(--paper); border-top: 1px solid var(--ink); }
.ruler .scale { position: relative; height: 34px; border-right: 1px solid var(--ink); background:
  repeating-linear-gradient(to right, var(--ink) 0 1px, transparent 1px 20%) 0 0 / 100% 10px no-repeat,
  repeating-linear-gradient(to right, #b9c6c8 0 1px, transparent 1px 4%) 0 0 / 100% 5px no-repeat; }
.ruler .scale::after { content: ""; position: absolute; right: -1px; top: 10px; bottom: 0; background: var(--paper); width: 2px; }
.ruler span { position: absolute; top: 15px; transform: translateX(-50%); font: 400 0.68rem/1 var(--mono); color: var(--ink-2); white-space: nowrap; }
.ruler span:first-child { transform: none; }
.ruler span:last-child { transform: translateX(-100%); }

.section { padding: 96px 0; }
.section-alt { background: var(--alt); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section p { color: var(--ink-2); }

.split { display: grid; grid-template-columns: 4fr 8fr; gap: 56px; align-items: start; }
.split-app { grid-template-columns: 5fr 7fr; }
.split-text h2 { max-width: 14ch; }
.sheet { margin: 0; }
.sheet img, .shot img { border: 1px solid var(--line); }
.sheet figcaption { margin-top: 12px; }
.shot { margin: 0; }

.spec { margin: 28px 0 0; border-top: 1px solid var(--ink); }
.spec div { display: grid; grid-template-columns: 112px 1fr; gap: 16px; padding: 12px 0; border-bottom: 1px solid var(--line); }
.spec dt { font: 500 0.72rem/1.9 var(--mono); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-2); }
.spec dd { margin: 0; font-size: 0.97rem; }

.steps { list-style: none; padding: 0; margin: 36px 0 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; border-top: 1px solid var(--ink); }
.steps li { padding: 20px 32px 0 0; }
.steps li + li { padding-left: 32px; border-left: 1px solid var(--line); }
.steps .mono { display: block; color: var(--ink-2); margin-bottom: 10px; }
.steps p { margin: 0; }

.section-dark { background: var(--deep); color: var(--on-deep); }
.section-dark h2 { color: #fff; }
.section-dark p { color: var(--on-deep-2); }
.beta { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: start; }
.spec-dark { border-top-color: rgba(255, 255, 255, 0.6); margin-top: 34px; }
.spec-dark div { border-bottom-color: var(--deep-line); }
.spec-dark dt { color: var(--on-deep-2); }
.spec-dark dd { color: var(--on-deep); }

.faq { display: grid; grid-template-columns: 4fr 8fr; gap: 56px; }
.faq-list { border-top: 1px solid var(--ink); }
.faq details { border-bottom: 1px solid var(--line); padding: 16px 0; }
.faq summary { cursor: pointer; font-weight: 600; list-style: none; position: relative; padding-right: 32px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 4px; top: -2px; font: 400 1.3rem var(--mono); color: var(--ink-2); }
.faq details[open] summary::after { content: "\2212"; }
.faq details p { margin: 8px 0 0; }

.site-footer { background: var(--deep); color: var(--on-deep); padding: 64px 0 0; overflow: hidden; }
.footer-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: end; }
.site-footer a { color: #fff; font-size: 1.25rem; font-weight: 600; text-decoration-color: var(--accent); text-underline-offset: 5px; }
.footer-note { color: var(--on-deep-2); font-size: 0.92rem; max-width: 440px; }
.footer-legal { display: flex; flex-direction: column; gap: 4px; text-align: right; color: var(--on-deep-2); font-size: 0.82rem; padding-bottom: 1em; }
.watermark { font: 700 clamp(8rem, 24vw, 20rem)/0.72 var(--sans); letter-spacing: -0.04em; color: rgba(255, 255, 255, 0.05); text-align: center; margin-top: 32px; height: 0.42em; user-select: none; }

@media (max-width: 960px) {
  .nav, .brand-sub { display: none; }
  .header-row { justify-content: space-between; }
  .portions-head, .split, .beta, .faq, .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .sp-row { grid-template-columns: repeat(2, 1fr); }
  .sp-row li { margin: 0; padding: 18px 20px 20px 0; border-right: 0; border-bottom: 1px solid var(--deep-line); }
  .sp-row li:nth-child(odd) { padding-right: 20px; border-right: 1px solid var(--deep-line); }
  .sp-row li:nth-child(even) { padding-left: 20px; }
  .steps { grid-template-columns: 1fr; }
  .steps li, .steps li + li { padding: 20px 0; border-left: 0; border-bottom: 1px solid var(--line); }
  .split-text h2 { max-width: none; }
  .footer-legal { text-align: left; }
  .section { padding: 64px 0; }
}
@media (max-width: 560px) {
  body { font-size: 16px; }
  .wrap-wide { padding: 0 16px; }
  .hero { padding-top: 44px; }
  .viewport { margin-top: 40px; }
  .viewport-frame { padding: 8px; }
  .viewport-meta span:first-child { max-width: 65%; }
  .sp-row { grid-template-columns: 1fr; }
  .sp-row li, .sp-row li:nth-child(odd), .sp-row li:nth-child(even) { padding: 16px 0; border-right: 0; }
  .spec div { grid-template-columns: 1fr; gap: 2px; }
  .ruler span:nth-child(2n) { display: none; }
  .hide-sm { display: none; }
}