/*
 * Hypermilers public site stylesheet.
 *
 * One dependency-free file shared by the marketing home page, the legal
 * policies and the error page. Colors come from the approved brand kit
 * (navy #061B27, green #16E56D, white) and every surface follows the reader's
 * color-scheme preference.
 */

/* Brand palette, spacing and typography tokens used by every rule below. */
:root {
  --navy: #061b27;
  --green: #16e56d;
  --white: #ffffff;

  --bg: var(--white);
  --surface: #f5f8f9;
  --surface-strong: #eaf0f2;
  --text: #0b1f2a;
  --muted: #4b5f6b;
  --border: #d9e3e7;
  --accent: #0d7a41;
  --button-bg: var(--navy);
  --button-text: var(--white);
  --focus: #0b63c5;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 16px;
  --space-4: 24px;
  --space-5: 32px;
  --space-6: 48px;
  --space-7: 72px;

  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
    Arial, "Noto Sans", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;

  --measure: 68ch;
  --content-width: 1120px;
}

/* Dark palette: navy canvas with the green accent kept for interactive states. */
@media (prefers-color-scheme: dark) {
  :root {
    --bg: var(--navy);
    --surface: #0b2432;
    --surface-strong: #0f2d3d;
    --text: #eaf2f5;
    --muted: #a9c0cc;
    --border: #1d3b4b;
    --accent: var(--green);
    --button-bg: var(--green);
    --button-text: var(--navy);
    --focus: var(--green);
  }
}

/* Reset: predictable box model and no unexpected margins or list markers. */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.65;
  overflow-wrap: break-word;
}

/* Long legal pages read better with calm headings and spaced sections. */
h1,
h2,
h3,
h4 {
  line-height: 1.25;
  margin: 0 0 var(--space-3);
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(1.9rem, 4vw, 2.75rem);
}

h2 {
  font-size: clamp(1.35rem, 2.4vw, 1.7rem);
  margin-top: var(--space-6);
}

h3 {
  font-size: 1.15rem;
  margin-top: var(--space-4);
}

p,
ul,
ol,
dl,
table,
blockquote {
  margin: 0 0 var(--space-3);
}

ul,
ol {
  padding-inline-start: 1.35rem;
}

li + li {
  margin-top: var(--space-1);
}

a {
  color: var(--accent);
  text-underline-offset: 3px;
}

a:hover {
  text-decoration-thickness: 2px;
}

strong {
  font-weight: 650;
}

code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--surface-strong);
  border-radius: var(--radius-sm);
  padding: 0.1em 0.35em;
}

/* Focus stays visible for keyboard users on every interactive surface. */
:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* Skip link is hidden until it receives keyboard focus. */
.skip-link {
  position: absolute;
  left: var(--space-3);
  top: -100px;
  z-index: 100;
  padding: var(--space-2) var(--space-3);
  background: var(--surface-strong);
  color: var(--text);
  border-radius: var(--radius-sm);
  text-decoration: none;
}

.skip-link:focus {
  top: var(--space-3);
}

/* Shared centered container with readable gutters on small screens. */
.container {
  width: 100%;
  max-width: var(--content-width);
  margin-inline: auto;
  padding-inline: clamp(1rem, 5vw, 2.5rem);
}

/* Sticky header keeps navigation reachable on long policy pages. */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2) var(--space-4);
  padding-block: var(--space-3);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: inherit;
}

/* The navy artwork is used on light surfaces, the white artwork on dark. */
.brand-logo {
  display: block;
  width: clamp(132px, 18vw, 176px);
  height: auto;
}

.brand-logo--dark {
  display: none;
}

@media (prefers-color-scheme: dark) {
  .brand-logo--light {
    display: none;
  }

  .brand-logo--dark {
    display: block;
  }
}

/* Navigation wraps instead of collapsing, so it works without JavaScript. */
.site-nav ul {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1) var(--space-3);
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-nav li {
  margin: 0;
}

.site-nav a {
  display: inline-block;
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
  color: var(--muted);
  font-size: 0.95rem;
  text-decoration: none;
}

.site-nav a:hover {
  color: var(--text);
  background: var(--surface);
}

.site-nav a[aria-current="page"] {
  color: var(--text);
  font-weight: 650;
}

/* Hero: single column on phones, balanced two-column layout on wide screens. */
.hero {
  padding-block: clamp(2.5rem, 7vw, 5rem);
  border-bottom: 1px solid var(--border);
}

.hero-grid {
  display: grid;
  gap: var(--space-5);
  align-items: center;
}

@media (min-width: 900px) {
  .hero-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  }
}

.hero h1 {
  max-width: 22ch;
}

.hero-lede {
  max-width: 52ch;
  color: var(--muted);
  font-size: clamp(1.02rem, 1.6vw, 1.15rem);
}

.eyebrow {
  display: inline-block;
  margin-bottom: var(--space-3);
  padding: var(--space-1) var(--space-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  font-size: 0.8rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-block: var(--space-4);
}

/* Buttons are real links so they work without scripts and are keyboard reachable. */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  min-height: 48px;
  padding: var(--space-2) var(--space-4);
  border: 1px solid transparent;
  border-radius: 999px;
  background: var(--button-bg);
  color: var(--button-text);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
}

.btn:hover {
  filter: brightness(1.08);
}

.btn--secondary {
  background: transparent;
  border-color: var(--border);
  color: var(--text);
}

.btn--secondary:hover {
  background: var(--surface);
  filter: none;
}

/* Decorative hero mark: approved monogram artwork, never recolored. */
.hero-mark {
  justify-self: center;
  width: min(280px, 60vw);
  height: auto;
  padding: var(--space-4);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--navy);
}

/* Section rhythm shared by every content block. */
.section {
  padding-block: clamp(2.25rem, 5vw, 3.5rem);
}

.section-heading {
  max-width: 60ch;
  margin-bottom: var(--space-4);
}

.section-heading p {
  color: var(--muted);
  margin-bottom: 0;
}

/* Card grid reflows from one column to three without media-query bookkeeping. */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 260px), 1fr));
  gap: var(--space-3);
  margin: 0;
  padding: 0;
  list-style: none;
}

.card {
  padding: var(--space-4);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.card li,
.card {
  margin: 0;
}

.card h3 {
  margin-top: 0;
}

.card p {
  color: var(--muted);
  margin-bottom: 0;
}

.card--link {
  display: block;
  color: inherit;
  text-decoration: none;
}

.card--link:hover {
  border-color: var(--accent);
}

.card--link h3 {
  color: var(--text);
}

.card--link .card-cta {
  display: inline-block;
  margin-top: var(--space-3);
  color: var(--accent);
  font-weight: 650;
}

/* Plan comparison table stays readable on narrow screens by scrolling. */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.97rem;
}

caption {
  padding: var(--space-3);
  color: var(--muted);
  text-align: start;
}

th,
td {
  padding: var(--space-2) var(--space-3);
  border-bottom: 1px solid var(--border);
  text-align: start;
  vertical-align: top;
}

thead th {
  background: var(--surface);
}

tbody tr:last-child th,
tbody tr:last-child td {
  border-bottom: 0;
}

/* FAQ uses native disclosure so it works without scripts. */
.faq {
  display: grid;
  gap: var(--space-2);
}

.faq details {
  padding: var(--space-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.faq summary {
  cursor: pointer;
  font-weight: 650;
}

.faq summary::marker {
  color: var(--accent);
}

.faq p {
  margin: var(--space-2) 0 0;
  color: var(--muted);
}

/* Policy pages: constrained measure, clear metadata and a jump list. */
.prose {
  max-width: var(--measure);
  padding-block: clamp(2rem, 5vw, 3rem);
}

.prose > h2:first-of-type {
  margin-top: var(--space-5);
}

.prose h2 + h3 {
  margin-top: var(--space-3);
}

.meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-3);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.92rem;
}

.toc {
  margin-block: var(--space-4);
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.toc h2 {
  margin: 0 0 var(--space-2);
  font-size: 1rem;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--muted);
}

.toc ol {
  margin: 0;
  padding-inline-start: 1.2rem;
  columns: 2;
  column-gap: var(--space-4);
}

@media (max-width: 640px) {
  .toc ol {
    columns: 1;
  }
}

.toc li {
  margin-block: var(--space-1);
}

.toc a {
  text-decoration: none;
}

.toc a:hover {
  text-decoration: underline;
}

/* Callouts flag limits, retention windows and legal exceptions. */
.callout {
  margin-block: var(--space-4);
  padding: var(--space-3) var(--space-4);
  border-inline-start: 4px solid var(--accent);
  border-radius: var(--radius-sm);
  background: var(--surface);
}

.callout p:last-child {
  margin-bottom: 0;
}

/* Definition list pairs a data category with its purpose and retention. */
dl.data-list {
  display: grid;
  gap: var(--space-2);
}

dl.data-list dt {
  font-weight: 650;
}

dl.data-list dd {
  margin: 0 0 var(--space-2);
  padding-inline-start: var(--space-3);
  border-inline-start: 2px solid var(--border);
  color: var(--muted);
}

/* Footer closes every page with navigation, contact and trademark notices. */
.site-footer {
  margin-top: var(--space-6);
  padding-block: var(--space-5);
  border-top: 1px solid var(--border);
  background: var(--surface);
  color: var(--muted);
  font-size: 0.92rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 210px), 1fr));
  gap: var(--space-4);
}

.footer-grid h2 {
  margin: 0 0 var(--space-2);
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text);
}

.footer-grid ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer-grid li {
  margin-block: var(--space-1);
}

.footer-grid a {
  color: inherit;
  text-decoration: none;
}

.footer-grid a:hover {
  color: var(--text);
  text-decoration: underline;
}

.footer-legal {
  margin-top: var(--space-5);
  padding-top: var(--space-3);
  border-top: 1px solid var(--border);
}

.footer-legal p {
  margin: 0 0 var(--space-1);
}

/* The error page reuses the legal layout with a centered message. */
.error-page {
  max-width: 56ch;
  padding-block: clamp(3rem, 10vw, 6rem);
}

/* Printing a policy drops navigation chrome and forces readable ink. */
@media print {
  .site-header,
  .site-footer,
  .toc,
  .skip-link {
    display: none;
  }

  :root {
    --bg: #ffffff;
    --text: #000000;
    --muted: #333333;
  }

  body {
    font-size: 11pt;
  }

  a {
    color: #000000;
    text-decoration: underline;
  }

  .prose {
    max-width: none;
  }
}

/* Readers who ask for less motion get no smooth scrolling. */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}