/* TerraShift landing page. The colours follow the tool: its link blue, and
   the change colours (blue = new buildings or bare ground, green = plants
   gained, red = plants lost, dark orange = burned, brown = the terrain profile). */
:root {
  --space: #0b1a2b;        /* the dark night-side blue of the hero and footer */
  --space-2: #12304d;
  --ink: #1b2733;          /* body text */
  --muted: #56636f;
  --line: #dde3e8;
  --tint: #f3f6f8;         /* the background of every other section */
  --paper: #ffffff;
  --accent: #1a6fd0;       /* buttons, close to the tool's link blue */
  --accent-dark: #1459a8;
  --link: #1a5fb4;         /* the tool's link colour */
  --sand: #e0b878;         /* desert sand, for small highlights */
  --built: #0074d9;
  --gained: #2ecc40;
  --lost: #ff4136;
  --burned: #a64b00;
  --terrain: #8a5a2b;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(11, 26, 43, 0.12);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 17px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--paper);
  -webkit-text-size-adjust: 100%;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: var(--link);
}

h1,
h2,
h3 {
  line-height: 1.2;
  margin: 0;
}

h2 {
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
  letter-spacing: -0.01em;
  margin-bottom: 12px;
}

h3 {
  font-size: 1.1rem;
}

.wrap {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 20px;
}

.narrow {
  max-width: 760px;
}

/* For keyboard users: a link straight to the content, visible when focused */
.skip-link {
  position: absolute;
  left: 12px;
  top: -60px;
  z-index: 100;
  padding: 8px 14px;
  background: var(--paper);
  border-radius: 8px;
}

.skip-link:focus {
  top: 12px;
}

:focus-visible {
  outline: 3px solid var(--sand);
  outline-offset: 2px;
}

/* --- Buttons --- */
.button {
  display: inline-block;
  font-weight: 600;
  text-decoration: none;
  color: #fff;
  background: var(--accent);
  border-radius: 10px;
  transition: background 0.15s, transform 0.15s;
}

.button:hover {
  background: var(--accent-dark);
  transform: translateY(-1px);
}

.button-large {
  font-size: 1.1rem;
  padding: 14px 28px;
  box-shadow: 0 6px 20px rgba(26, 111, 208, 0.4);
}

.button-small {
  font-size: 0.95rem;
  padding: 7px 16px;
}

/* --- Header --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(11, 26, 43, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.header-row {
  display: flex;
  align-items: center;
  gap: 24px;
  height: 60px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.15rem;
  color: #fff;
  text-decoration: none;
}

.brand-icon {
  width: 30px;
  height: 30px;
}

.site-nav {
  display: flex;
  gap: 22px;
  margin-left: auto;
}

.site-nav a {
  color: rgba(255, 255, 255, 0.8);
  text-decoration: none;
  font-size: 0.95rem;
}

.site-nav a:hover {
  color: #fff;
}

/* --- Hero --- */
.hero {
  color: #fff;
  background:
    radial-gradient(ellipse at 80% 20%, rgba(26, 111, 208, 0.35), transparent 55%),
    radial-gradient(ellipse at 10% 90%, rgba(224, 184, 120, 0.16), transparent 50%),
    linear-gradient(180deg, var(--space) 0%, var(--space-2) 100%);
  padding: 64px 0 72px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
}

.eyebrow {
  margin: 0 0 10px;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--sand);
}

.hero h1 {
  font-size: clamp(2.8rem, 7vw, 4.4rem);
  letter-spacing: -0.03em;
}

.tagline {
  margin: 6px 0 18px;
  font-size: clamp(1.3rem, 3vw, 1.7rem);
  color: rgba(255, 255, 255, 0.92);
}

.lead {
  margin: 0 0 28px;
  max-width: 34em;
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.78);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 22px;
}

.text-link {
  color: #fff;
  font-weight: 500;
}

.hero-note {
  margin: 18px 0 0;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.6);
}

/* --- The before/after slider --- */
.hero-figure {
  margin: 0;
}

.compare {
  --position: 50%;
  position: relative;
  aspect-ratio: 1 / 1;
  overflow: hidden;
  border-radius: var(--radius);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.45);
  background: var(--space-2);
  cursor: ew-resize;
  user-select: none;
  -webkit-user-select: none;
  touch-action: pan-y; /* a sideways drag moves the line; an up-down swipe still scrolls the page */
}

.compare img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  pointer-events: none;
}

/* The before photo is cut off at the line, so the after photo shows to its right */
.compare-before {
  clip-path: inset(0 calc(100% - var(--position)) 0 0);
}

.compare-label {
  position: absolute;
  top: 12px;
  padding: 3px 10px;
  font-size: 0.8rem;
  font-weight: 600;
  color: #fff;
  background: rgba(11, 26, 43, 0.7);
  border-radius: 999px;
  pointer-events: none;
}

.compare-label-before {
  left: 12px;
}

.compare-label-after {
  right: 12px;
}

.compare-handle {
  position: absolute;
  top: 0;
  bottom: 0;
  left: var(--position);
  width: 3px;
  margin-left: -1.5px;
  background: #fff;
  box-shadow: 0 0 6px rgba(0, 0, 0, 0.5);
  pointer-events: none;
}

.compare-handle span {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 42px;
  height: 42px;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.4);
}

/* Two small arrows inside the round handle */
.compare-handle span::before,
.compare-handle span::after {
  content: "";
  position: absolute;
  top: 50%;
  width: 0;
  height: 0;
  margin-top: -6px;
  border: 6px solid transparent;
}

.compare-handle span::before {
  left: 6px;
  border-right-color: var(--space);
}

.compare-handle span::after {
  right: 6px;
  border-left-color: var(--space);
}

/* The slider input is invisible but there for the keyboard and screen readers */
.compare-range {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  margin: 0;
  opacity: 0;
  pointer-events: none;
}

.compare:focus-within .compare-handle span {
  outline: 3px solid var(--sand);
  outline-offset: 2px;
}

.hero-figure figcaption {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-top: 12px;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.7);
}

.chip {
  font: inherit;
  font-weight: 600;
  padding: 6px 14px;
  color: #fff;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 999px;
  cursor: pointer;
}

.chip:hover {
  background: rgba(255, 255, 255, 0.2);
}

.chip[aria-pressed="true"] {
  background: var(--built);
  border-color: var(--built);
}

/* --- Sections --- */
.section {
  padding: 80px 0;
}

.section-tint {
  background: var(--tint);
}

.section-lead {
  margin: 0 0 32px;
  color: var(--muted);
}

/* How it works */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin: 28px 0 48px;
  padding: 0;
  list-style: none;
}

.steps li {
  padding: 26px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.step-number {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  margin-bottom: 14px;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, var(--accent), var(--space-2));
  border-radius: 50%;
}

.steps h3 {
  margin-bottom: 6px;
}

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

.tool-shot {
  margin: 0;
}

.tool-shot img {
  border-radius: var(--radius);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.tool-shot figcaption,
.card-place {
  margin-top: 10px;
  font-size: 0.88rem;
  color: var(--muted);
}

/* What it can show */
.cards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
}

.card {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 2px 8px rgba(11, 26, 43, 0.05);
}

.card img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.card-body {
  padding: 18px 20px 20px;
}

.card h3 {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 8px;
}

.card p {
  margin: 0;
  font-size: 0.95rem;
}

.card .card-place {
  margin-top: 10px;
  font-size: 0.82rem;
}

.swatch {
  flex: none;
  width: 14px;
  height: 14px;
  border-radius: 3px;
}

.swatch-built { background: var(--built); }
.swatch-gained { background: var(--gained); }
.swatch-lost { background: var(--lost); }
.swatch-burned { background: var(--burned); }
.swatch-terrain { background: linear-gradient(135deg, #eee, #555); }

/* Try an example */
.examples {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.example {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 22px 24px;
  text-decoration: none;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 5px solid var(--accent);
  border-radius: var(--radius);
  transition: box-shadow 0.15s, transform 0.15s;
}

.example:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.example strong {
  color: var(--link);
  font-size: 1.05rem;
}

.example strong::after {
  content: " →";
}

.example span {
  color: var(--muted);
  font-size: 0.95rem;
}

/* What it can and can't do */
.limits {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 22px;
}

.limit-box {
  padding: 26px 28px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.limit-box h3 {
  margin-bottom: 10px;
}

.limit-box ul {
  margin: 0;
  padding-left: 20px;
}

.limit-box li + li {
  margin-top: 8px;
}

.limit-can {
  border-top: 4px solid var(--gained);
}

.limit-cannot {
  border-top: 4px solid var(--lost);
}

.limits-link {
  margin: 26px 0 0;
}

.limits-link a {
  font-weight: 600;
}

/* The last call to action */
.cta {
  padding: 56px 0;
  color: #fff;
  background:
    radial-gradient(ellipse at 90% 50%, rgba(26, 111, 208, 0.35), transparent 60%),
    var(--space-2);
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.cta p {
  margin: 0;
  font-size: clamp(1.3rem, 3vw, 1.6rem);
  font-weight: 600;
}

/* --- Footer --- */
.site-footer {
  padding: 40px 0;
  font-size: 0.92rem;
  color: rgba(255, 255, 255, 0.7);
  background: var(--space);
}

.footer-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 24px;
}

.site-footer strong {
  color: #fff;
}

.site-footer p {
  margin: 4px 0 0;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  align-items: center;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.85);
}

.footer-links a:hover {
  color: #fff;
}

/* --- Tablets --- */
@media (max-width: 960px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero-figure {
    max-width: 560px;
  }

  .cards {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* --- Phones --- */
@media (max-width: 720px) {
  body {
    font-size: 16px;
  }

  .wrap {
    padding: 0 16px;
  }

  .site-nav {
    display: none;
  }

  .header-row {
    justify-content: space-between;
  }

  .hero {
    padding: 40px 0 48px;
  }

  .section {
    padding: 56px 0;
  }

  .steps,
  .examples,
  .limits {
    grid-template-columns: 1fr;
  }

  .steps {
    gap: 14px;
    margin-bottom: 32px;
  }

  .cards {
    grid-template-columns: 1fr;
  }

  .button-large {
    width: 100%;
    text-align: center;
  }

  .cta-row {
    flex-direction: column;
    align-items: stretch;
    text-align: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .button,
  .example {
    transition: none;
  }
}