/* LINHBUI.ART Phase 2 prototypes — Nornorm layout/style (Linh-locked 2026-07-11).
   Not production CSS. Author: CHILLINH.
   Source: https://styles.refero.design/style/0769ff4c-f719-4865-98df-de2f44c694a6 */

:root {
  color-scheme: light;
  --color-canvas: #ffffff;
  --color-bone: #f1efe9;
  --color-ash: #ececec;
  --color-stone: #6a6a6a;
  --color-graphite: #333333;
  --color-ink: #1f1d1e;
  --color-obsidian: #000000;
  --color-cobalt: #1e37a0;
  --color-gold: #ffd700;
  --color-hairline: #e5e5e5;

  --font: "Instrument Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --tracking: -0.03em;

  --text-caption: 0.875rem;
  --text-body-sm: 1rem;
  --text-body: 1.25rem;
  --text-subheading: 1.5rem;
  --text-heading-sm: 2rem;
  --text-heading: 3rem;
  --text-heading-lg: 4rem;
  --text-display: clamp(3rem, 8vw, 7rem);

  --space-4: 4px;
  --space-8: 8px;
  --space-12: 12px;
  --space-16: 16px;
  --space-24: 24px;
  --space-32: 32px;
  --space-48: 48px;
  --space-64: 64px;
  --space-80: 80px;
  --page-max: 1280px;
  --section-gap: 80px;
  --element-gap: 16px;
  --card-pad: 24px;
  --header-h: 72px;
  --proto-offset: 0px;
  --radius-ui: 8px;
  --radius-pill: 9999px;
}

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

html {
  background: var(--color-canvas);
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--color-canvas);
  color: var(--color-ink);
  font-family: var(--font);
  font-size: var(--text-body-sm);
  font-weight: 400;
  line-height: 1.3;
  letter-spacing: var(--tracking);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

img,
video {
  max-width: 100%;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
}

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--color-cobalt);
  outline-offset: 3px;
}

.container {
  width: min(var(--page-max), calc(100% - 48px));
  margin-inline: auto;
}

/* Design-review banners stay in markup for agents, hidden during visual QA. */
.proto-banner {
  display: none;
}

/* —— Header / Nav —— transparent over hero, solid white after —— */
.site-header {
  position: fixed;
  inset: var(--proto-offset, 0px) 0 auto 0;
  z-index: 50;
  height: var(--header-h);
  background: rgba(255, 255, 255, 0.42);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition:
    background 0.28s ease,
    border-color 0.28s ease,
    box-shadow 0.28s ease,
    backdrop-filter 0.28s ease;
}

.site-header.is-scrolled {
  background: var(--color-canvas);
  -webkit-backdrop-filter: none;
  backdrop-filter: none;
  border-bottom-color: var(--color-hairline);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.04);
}

.site-nav {
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-24);
}

.brand {
  display: inline-flex;
  flex-direction: column;
  line-height: 1.05;
  font-size: 1.25rem;
  font-weight: 500;
  letter-spacing: var(--tracking);
  color: var(--color-cobalt);
  text-transform: uppercase;
}

.brand span {
  display: block;
}

/* "ART" is the contrast mark — heavier + gold */
.brand .brand-art {
  font-weight: 800;
  color: var(--color-gold);
}

.nav-links {
  display: none;
  align-items: center;
  gap: var(--space-24);
  font-size: var(--text-body-sm);
  font-weight: 500;
  color: var(--color-obsidian);
}

.nav-links a:hover {
  color: var(--color-cobalt);
}

.nav-links a[aria-current="page"] {
  color: var(--color-cobalt);
}

.nav-cta {
  display: none;
}

.nav-toggle {
  list-style: none;
  cursor: pointer;
  border: 1px solid var(--color-obsidian);
  border-radius: var(--radius-pill);
  padding: 10px 16px;
  font-size: var(--text-caption);
  font-weight: 500;
  background: transparent;
}

.nav-toggle::-webkit-details-marker {
  display: none;
}

.mobile-panel {
  position: absolute;
  right: 24px;
  top: calc(var(--header-h) + 8px);
  width: min(240px, calc(100vw - 32px));
  display: grid;
  gap: 4px;
  padding: 8px;
  border-radius: var(--radius-ui);
  border: 1px solid var(--color-hairline);
  background: var(--color-canvas);
}

.mobile-panel a {
  padding: 12px;
  border-radius: var(--radius-ui);
  font-weight: 500;
}

.mobile-panel a:hover {
  background: var(--color-bone);
}

@media (min-width: 900px) {
  .nav-links,
  .nav-cta {
    display: flex;
  }

  .nav-mobile {
    display: none;
  }
}

/* —— Buttons (Nornorm two-button unit) —— */
.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-16);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-pill);
  padding: 12px 24px;
  font-size: var(--text-body-sm);
  font-weight: 500;
  letter-spacing: var(--tracking);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn-primary {
  background: var(--color-cobalt);
  color: var(--color-canvas);
}

.btn-primary:hover {
  background: #182d86;
}

.btn-ghost {
  background: transparent;
  color: var(--color-obsidian);
  border-color: var(--color-obsidian);
}

.btn-ghost:hover {
  background: var(--color-obsidian);
  color: var(--color-canvas);
}

.btn-ghost.on-dark {
  color: var(--color-canvas);
  border-color: var(--color-canvas);
}

.btn-ghost.on-dark:hover {
  background: var(--color-canvas);
  color: var(--color-obsidian);
}

/* —— Section chrome —— */
.section {
  padding-block: var(--section-gap);
}

.section-bone {
  background: var(--color-bone);
}

.section-head {
  text-align: center;
  max-width: 40rem;
  margin: 0 auto var(--space-64);
}

.section-head h2 {
  margin: 0;
  font-size: clamp(2rem, 4vw, var(--text-heading));
  font-weight: 400;
  line-height: 1;
  letter-spacing: var(--tracking);
  color: var(--color-obsidian);
}

.section-head p {
  margin: var(--space-8) 0 0;
  font-size: var(--text-body);
  font-weight: 400;
  color: var(--color-stone);
  line-height: 1.3;
}

.eyebrow {
  margin: 0 0 var(--space-12);
  font-size: var(--text-caption);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: var(--tracking);
  color: var(--color-cobalt);
}

.muted {
  color: var(--color-stone);
}

.soft {
  color: #8a8a8a;
}

.chip {
  display: inline-flex;
  align-items: center;
  border-radius: var(--radius-pill);
  padding: 4px 10px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: var(--tracking);
  text-transform: uppercase;
  background: var(--color-bone);
  color: var(--color-obsidian);
}

.chip-available {
  background: rgba(30, 55, 160, 0.12);
  color: var(--color-cobalt);
}

.chip-beta {
  background: rgba(30, 55, 160, 0.08);
  color: var(--color-cobalt);
}

.chip-private,
.chip-concept {
  background: #ebe7df;
  color: #333;
  border: 1px solid rgba(17, 17, 17, 0.12);
}

.project-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 12px;
  align-items: center;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font);
  letter-spacing: var(--tracking);
  margin: 0;
  font-weight: 500;
}

/* —— Filters —— */
.filters {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-8);
  margin-bottom: var(--space-48);
}

.filters button {
  appearance: none;
  border: none;
  background: transparent;
  color: var(--color-stone);
  border-radius: var(--radius-pill);
  padding: 8px 16px;
  font-family: var(--font);
  font-size: var(--text-body-sm);
  font-weight: 500;
  letter-spacing: var(--tracking);
  cursor: pointer;
}

.filters button[aria-pressed="true"],
.filters button.active {
  color: var(--color-cobalt);
  background: rgba(30, 55, 160, 0.08);
}

.measure-note {
  font-size: var(--text-caption);
  color: var(--color-stone);
  border-top: 1px dashed var(--color-hairline);
  margin-top: var(--space-48);
  padding-top: var(--space-16);
}

/* Fixed media frames: layout owns the box; media scales inside.
   Orientation is chosen by class — never force landscape into portrait. */
.media-frame {
  position: relative;
  overflow: hidden;
  background: var(--color-ash);
  border-radius: 0;
}

.media-frame > img,
.media-frame > video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center center;
  border-radius: 0;
}

.media-frame.is-contain > img,
.media-frame.is-contain > video {
  object-fit: contain;
  object-position: center center;
}

.media-frame.ratio-4x3 {
  aspect-ratio: 4 / 3;
}

.media-frame.ratio-16x9 {
  aspect-ratio: 16 / 9;
}

.media-frame.ratio-21x9 {
  aspect-ratio: 21 / 9;
}

.media-frame.ratio-3x4 {
  aspect-ratio: 3 / 4;
}

.media-frame.ratio-9x16 {
  aspect-ratio: 9 / 16;
}

/* Anchors clear fixed header + proto banner */
[id] {
  scroll-margin-top: calc(var(--proto-offset, 0px) + var(--header-h) + 16px);
}

html {
  overflow-anchor: none;
}

/* Scroll to top */
.scroll-top {
  position: fixed;
  right: 20px;
  bottom: 24px;
  z-index: 55;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-obsidian);
  background: var(--color-canvas);
  color: var(--color-obsidian);
  font-size: 1.25rem;
  line-height: 1;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.12);
  transition: opacity 0.2s ease, background 0.2s ease, color 0.2s ease;
}

.scroll-top.is-visible {
  opacity: 1;
  pointer-events: auto;
}

.scroll-top:hover {
  background: var(--color-obsidian);
  color: var(--color-canvas);
}