/* ==========================================================================
   Chilverstone Engineering — design options overview page
   Standalone stylesheet for the presentation sheet only.
   ========================================================================== */

:root {
  --black: #0a0a0a;
  --charcoal: #17181b;
  --charcoal-2: #1f2125;
  --charcoal-3: #26292e;
  --silver: #c7c9ce;
  --blue: #2977ff;
  --white: #ffffff;
  --text: #e8e9ec;
  --text-dim: #a9adb5;
  --text-faint: #7d828b;
  --hairline: rgba(199, 201, 206, 0.16);
  --hairline-strong: rgba(199, 201, 206, 0.32);
  --font-display: "Barlow Condensed", "Oswald", "Arial Narrow", Arial, sans-serif;
  --font-body: "Inter", "Segoe UI", system-ui, Arial, sans-serif;
  --font-mono: "IBM Plex Mono", Consolas, "Courier New", monospace;
  --radius: 3px;
  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
}

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

body {
  margin: 0;
  background: var(--black);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--silver);
  text-decoration: none;
}

a:hover {
  color: var(--white);
}

h1,
h2,
h3 {
  font-family: var(--font-display);
  font-weight: 700;
  text-transform: uppercase;
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--white);
  margin: 0 0 0.6rem;
}

p {
  margin: 0 0 1rem;
  color: var(--text-dim);
}

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

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

.wrap {
  width: min(100% - 3rem, 1180px);
  margin-inline: auto;
}

.kicker {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--blue);
}

.kicker::before {
  content: "";
  width: 28px;
  height: 2px;
  background: var(--blue);
}

.site-head {
  padding: 3rem 0 2rem;
  border-bottom: 1px solid var(--hairline);
  background: var(--charcoal);
  background-image:
    linear-gradient(to right, rgba(199, 201, 206, 0.055) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(199, 201, 206, 0.055) 1px, transparent 1px);
  background-size: 72px 72px;
}

.brandline {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 2rem;
}

.brandline img {
  width: 44px;
  height: 44px;
}

.brandline strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.5rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--white);
  line-height: 1;
}

.brandline__text span {
  display: block;
  font-size: 0.6rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--silver);
}

.site-head h1 {
  font-size: clamp(2rem, 1.2rem + 3vw, 3.4rem);
  max-width: 22ch;
}

.site-head p {
  max-width: 68ch;
  font-size: 1.0625rem;
}

.section {
  padding: 3.5rem 0;
  border-bottom: 1px solid var(--hairline);
}

.section h2 {
  font-size: clamp(1.6rem, 1.1rem + 1.6vw, 2.4rem);
}

.lede {
  max-width: 70ch;
  font-size: 1.0625rem;
}

.options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(330px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.option {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  padding: 1.5rem;
  background: var(--charcoal-2);
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  transition: border-color 250ms var(--ease), transform 250ms var(--ease);
}

.option:hover {
  border-color: var(--blue);
  transform: translateY(-3px);
}

.option__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
}

.option__num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  color: var(--blue);
}

.option h3 {
  font-size: 1.6rem;
  margin: 0;
}

.option__tag {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.option p {
  font-size: 0.9375rem;
  margin: 0;
}

.option ul {
  display: grid;
  gap: 0.4rem;
  font-size: 0.875rem;
  color: var(--text-dim);
}

.option ul li {
  position: relative;
  padding-left: 1.1rem;
}

.option ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 7px;
  height: 7px;
  border: 2px solid var(--blue);
}

.option__link {
  margin-top: auto;
  padding-top: 0.75rem;
  border-top: 1px solid var(--hairline);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--blue);
}

.option__link::after {
  content: " \2192";
}

/* Mini previews ------------------------------------------------------------ */
.preview {
  border: 1px solid var(--hairline-strong);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--black);
}

.preview__bar {
  display: flex;
  gap: 4px;
  padding: 6px 8px;
  background: rgba(199, 201, 206, 0.1);
}

.preview__bar span {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: rgba(199, 201, 206, 0.4);
}

.preview__canvas {
  position: relative;
  height: 128px;
  padding: 8px;
}

.preview__nav {
  height: 8px;
  margin-bottom: 8px;
  background: rgba(199, 201, 206, 0.3);
}

.preview__hero {
  height: 42px;
  margin-bottom: 8px;
}

.preview__row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
}

.preview__row span {
  height: 24px;
  background: rgba(199, 201, 206, 0.16);
}

/* Forge: dark, blue banner */
.preview--forge .preview__canvas {
  background: #0a0a0a;
}

.preview--forge .preview__hero {
  background: linear-gradient(100deg, #1b1d21, #0d0e10), #0a0a0a;
  border-left: 3px solid var(--blue);
}

/* Blueprint: light, technical */
.preview--blueprint .preview__canvas {
  background: #f4f5f7;
  background-image:
    linear-gradient(to right, rgba(41, 119, 255, 0.12) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(41, 119, 255, 0.12) 1px, transparent 1px);
  background-size: 16px 16px;
}

.preview--blueprint .preview__nav {
  background: #22252a;
}

.preview--blueprint .preview__hero {
  background: #ffffff;
  border: 1px solid #c7c9ce;
}

.preview--blueprint .preview__row span {
  background: #ffffff;
  border: 1px solid #c7c9ce;
}

/* Steel Edge: split screen */
.preview--steel-edge .preview__canvas {
  background: #0a0a0a;
}

.preview--steel-edge .preview__hero {
  background: linear-gradient(90deg, #17181b 0 50%, #2b2f36 50% 100%);
  border-bottom: 2px solid var(--blue);
}

.preview--steel-edge .preview__row span:first-child {
  background: var(--blue);
}

/* Precision: minimal */
.preview--precision .preview__canvas {
  background: #050506;
}

.preview--precision .preview__nav {
  width: 60%;
  margin-inline: auto;
  background: rgba(199, 201, 206, 0.2);
}

.preview--precision .preview__hero {
  width: 70%;
  margin-inline: auto;
  background: rgba(255, 255, 255, 0.9);
}

.preview--precision .preview__row span {
  background: transparent;
  border-top: 1px solid rgba(199, 201, 206, 0.3);
}

/* Workshop: light cards */
.preview--workshop .preview__canvas {
  background: #f7f8fa;
}

.preview--workshop .preview__nav {
  background: #ffffff;
  border: 1px solid #dfe1e6;
}

.preview--workshop .preview__hero {
  background: #17181b;
  border-radius: 6px;
}

.preview--workshop .preview__row span {
  background: #ffffff;
  border: 1px solid #dfe1e6;
  border-radius: 6px;
  border-bottom: 3px solid var(--blue);
}

/* Shared content lists ----------------------------------------------------- */
.cols {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

.checklist {
  display: grid;
  gap: 0.5rem;
  font-size: 0.9375rem;
  color: var(--text-dim);
}

.checklist li {
  position: relative;
  padding-left: 1.4rem;
}

.checklist li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.5em;
  width: 8px;
  height: 8px;
  border: 2px solid var(--blue);
}

.panel {
  padding: 1.5rem;
  background: var(--charcoal-2);
  border: 1px solid var(--hairline);
  border-left: 3px solid var(--blue);
  border-radius: var(--radius);
}

.panel h3 {
  font-size: 1.25rem;
}

.panel--warn {
  border-left-color: #e0a33c;
}

.panel--warn h3 {
  color: #f0c26b;
}

.todo {
  display: grid;
  gap: 0.4rem;
  font-size: 0.9375rem;
  color: var(--text-dim);
  counter-reset: todo;
}

.todo li {
  position: relative;
  padding-left: 2rem;
  counter-increment: todo;
}

.todo li::before {
  content: counter(todo, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--blue);
  border: 1px solid var(--hairline-strong);
  width: 20px;
  height: 20px;
  display: grid;
  place-items: center;
}

.note {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-faint);
}

footer.site-foot {
  padding: 2.5rem 0 3.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-faint);
}

footer.site-foot p {
  font-size: inherit;
  color: inherit;
}

@media (max-width: 600px) {
  .wrap {
    width: min(100% - 2rem, 1180px);
  }
}