/* ============================================================
   ZHOU YI ART — Design System
   Premium dark-themed portfolio with gallery aesthetics
   ============================================================ */

/* --- Google Fonts Import --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600&family=Playfair+Display:ital,wght@0,400;0,600;0,700;1,400;1,600&display=swap');

/* --- CSS Custom Properties --- */
:root {
  /* Colors */
  --color-bg: #08080c;
  --color-bg-elevated: #111118;
  --color-bg-card: #16161f;
  --color-bg-hover: #1e1e2a;
  --color-surface: #1a1a24;
  --color-border: rgba(255, 255, 255, 0.06);
  --color-border-hover: rgba(255, 255, 255, 0.12);

  --color-text: #e8e6e3;
  --color-text-muted: #8a8a9a;
  --color-text-subtle: #5a5a6e;

  --color-accent: #c9a96e;
  --color-accent-hover: #dbbf88;
  --color-accent-dim: rgba(201, 169, 110, 0.15);

  /* Typography */
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-display: 'Playfair Display', Georgia, serif;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;
  --space-3xl: 8rem;

  /* Layout */
  --max-width: 1200px;
  --max-width-sm: 900px;
  --nav-height: 72px;
  --border-radius: 8px;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --duration: 0.5s;
}

/* --- Reset & Base --- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  font-weight: 300;
  overflow-x: hidden;
}

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

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

/* --- Typography --- */
h1,
h2,
h3 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  color: var(--color-text);
}

h2 {
  font-size: clamp(1.6rem, 3.5vw, 2.4rem);
  color: var(--color-text);
}

h3 {
  font-size: clamp(1.2rem, 2vw, 1.5rem);
  color: var(--color-text);
}

.subtitle {
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 300;
  color: var(--color-text-muted);
  line-height: 1.7;
  max-width: 540px;
}

.label {
  font-family: var(--font-body);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-lg);
  background: rgba(8, 8, 12, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border);
  transition: background var(--duration) var(--ease-out);
}

.nav-brand {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--color-text);
  white-space: nowrap;
}

.nav-brand span {
  color: var(--color-accent);
}

.nav-links {
  display: flex;
  list-style: none;
  gap: var(--space-lg);
}

.nav-links a {
  font-size: 0.82rem;
  font-weight: 400;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  transition: color 0.3s var(--ease-out);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--color-accent);
  transition: width 0.3s var(--ease-out);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-text);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

/* Mobile menu toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: transform 0.3s var(--ease-out), opacity 0.3s;
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* --- Main Content --- */
main {
  padding-top: var(--nav-height);
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.container--narrow {
  max-width: var(--max-width-sm);
}

section {
  padding: var(--space-3xl) 0;
}

/* --- Hero Section (Landing Page) --- */
.hero {
  min-height: calc(100vh - var(--nav-height));
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--space-xl) 0;
  position: relative;
}

.hero-content {
  max-width: 800px;
  margin: 0 auto;
}

.hero h1 {
  margin-bottom: var(--space-sm);
}

.hero .subtitle {
  margin: 0 auto var(--space-xl);
  max-width: 600px;
}

/* --- Dual Gateway Cards (Landing) --- */
.gateway {
  padding: var(--space-xl) 0 var(--space-3xl);
}

.gateway-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.gateway-card {
  position: relative;
  border-radius: var(--border-radius);
  overflow: hidden;
  aspect-ratio: 4/5;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  border: 1px solid var(--color-border);
  transition: border-color var(--duration) var(--ease-out),
    transform var(--duration) var(--ease-out);
}

.gateway-card:hover {
  border-color: var(--color-border-hover);
  transform: translateY(-4px);
}

.gateway-card__image {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.8s var(--ease-out), filter 0.8s var(--ease-out);
  filter: brightness(0.55);
}

.gateway-card:hover .gateway-card__image {
  transform: scale(1.04);
  filter: brightness(0.4);
}

.gateway-card__content {
  position: relative;
  z-index: 2;
  padding: var(--space-xl) var(--space-lg) var(--space-lg);
  background: linear-gradient(transparent, rgba(8, 8, 12, 0.95));
}

.gateway-card__label {
  display: inline-block;
  margin-bottom: var(--space-sm);
}

.gateway-card__title {
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 2.5vw, 2rem);
  font-weight: 600;
  margin-bottom: var(--space-xs);
  line-height: 1.25;
}

.gateway-card__subtitle {
  font-size: 0.9rem;
  font-weight: 300;
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: var(--space-md);
}

.gateway-card__cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent);
  transition: gap 0.3s var(--ease-out);
}

.gateway-card:hover .gateway-card__cta {
  gap: 14px;
}

.gateway-card__cta svg {
  width: 16px;
  height: 16px;
  stroke: var(--color-accent);
}

/* --- Page Header --- */
.page-header {
  padding: var(--space-3xl) 0 var(--space-xl);
  text-align: center;
  border-bottom: 1px solid var(--color-border);
}

.page-header .label {
  margin-bottom: var(--space-sm);
  display: block;
}

.page-header h1 {
  margin-bottom: var(--space-md);
}

.page-header .subtitle {
  margin: 0 auto;
}

/* --- Case Study Card --- */
.case-study {
  padding: var(--space-3xl) 0;
  border-bottom: 1px solid var(--color-border);
}

.case-study:last-child {
  border-bottom: none;
}

.case-study__header {
  margin-bottom: var(--space-xl);
}

.case-study__header .label {
  margin-bottom: var(--space-sm);
  display: block;
}

.case-study__header h2 {
  margin-bottom: var(--space-sm);
}

.case-study__header h2 em {
  font-style: italic;
  color: var(--color-accent);
}

.case-study__description {
  font-size: 1rem;
  color: var(--color-text-muted);
  max-width: 720px;
  line-height: 1.8;
}

/* Image Grids within Case Studies */
.case-images {
  display: grid;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.case-images--two {
  grid-template-columns: 1fr 1fr;
}

.case-images--three {
  grid-template-columns: 1fr 1fr 1fr;
}

.case-images--hero {
  grid-template-columns: 1fr;
}

.case-image-wrapper {
  border-radius: var(--border-radius);
  overflow: hidden;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  position: relative;
}

.case-image-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s var(--ease-out);
}

.case-image-wrapper:hover img {
  transform: scale(1.03);
}

.case-image-caption {
  padding: var(--space-sm) var(--space-md);
  font-size: 0.8rem;
  color: var(--color-text-subtle);
  text-align: center;
  background: var(--color-bg-card);
}

/* --- Panoramic Scroll Container (for横幅连图) --- */
.panoramic-scroll {
  width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  padding: var(--space-md) 0;
  scrollbar-width: thin;
  scrollbar-color: var(--color-accent) var(--color-bg-card);
}

.panoramic-scroll::-webkit-scrollbar {
  height: 4px;
}

.panoramic-scroll::-webkit-scrollbar-track {
  background: var(--color-bg-card);
}

.panoramic-scroll::-webkit-scrollbar-thumb {
  background: var(--color-accent);
  border-radius: 2px;
}

.panoramic-track {
  display: flex;
  gap: var(--space-sm);
  height: 420px;
}

.panoramic-track img {
  height: 100%;
  width: auto;
  border-radius: var(--border-radius);
  border: 1px solid var(--color-border);
  flex-shrink: 0;
}

/* --- Story Synopsis Panel --- */
.synopsis-panel {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  margin-top: var(--space-xl);
  padding: var(--space-xl);
  background: var(--color-bg-elevated);
  border-radius: var(--border-radius);
  border: 1px solid var(--color-border);
}

.synopsis-panel h3 {
  margin-bottom: var(--space-sm);
  color: var(--color-accent);
}

.synopsis-panel p {
  font-size: 0.95rem;
  color: var(--color-text-muted);
  line-height: 1.8;
}

/* --- Game Assets Grid --- */
.assets-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-md);
}

.asset-card {
  border-radius: var(--border-radius);
  overflow: hidden;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  transition: border-color 0.3s var(--ease-out), transform 0.3s var(--ease-out);
}

.asset-card:hover {
  border-color: var(--color-border-hover);
  transform: translateY(-2px);
}

.asset-card img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
}

/* --- About Page --- */
.about-hero {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: var(--space-xl);
  align-items: start;
  padding: var(--space-3xl) 0;
}

.about-photo {
  width: 300px;
  height: 380px;
  border-radius: var(--border-radius);
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: var(--color-bg-card);
}

.about-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.about-bio {
  padding-top: var(--space-sm);
}

.about-bio h1 {
  margin-bottom: var(--space-md);
}

.about-bio .bio-text {
  font-size: 1.05rem;
  line-height: 1.9;
  color: var(--color-text-muted);
  margin-bottom: var(--space-lg);
}

.about-bio .bio-text strong {
  color: var(--color-text);
  font-weight: 500;
}

/* Contact / Download section */
.about-contact {
  padding: var(--space-xl) 0;
  border-top: 1px solid var(--color-border);
}

.contact-row {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  flex-wrap: wrap;
}

.contact-email {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--color-accent);
  transition: color 0.3s;
}

.contact-email:hover {
  color: var(--color-accent-hover);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: var(--border-radius);
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  border: none;
  transition: all 0.3s var(--ease-out);
}

.btn--primary {
  background: var(--color-accent);
  color: var(--color-bg);
}

.btn--primary:hover {
  background: var(--color-accent-hover);
  transform: translateY(-1px);
}

.btn--outline {
  background: transparent;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
}

.btn--outline:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.btn svg {
  width: 16px;
  height: 16px;
}

/* --- Footer --- */
.footer {
  padding: var(--space-xl) 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.footer-email {
  color: var(--color-accent);
  font-size: 0.9rem;
  font-weight: 400;
}

.footer-email:hover {
  color: var(--color-accent-hover);
}

.footer-copy {
  font-size: 0.8rem;
  color: var(--color-text-subtle);
}

/* --- Scroll Animations --- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 {
  transition-delay: 0.1s;
}

.reveal-delay-2 {
  transition-delay: 0.2s;
}

.reveal-delay-3 {
  transition-delay: 0.3s;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .gateway-grid {
    gap: var(--space-md);
  }

  .case-images--three {
    grid-template-columns: 1fr 1fr;
  }

  .synopsis-panel {
    grid-template-columns: 1fr;
  }

  .about-hero {
    grid-template-columns: 240px 1fr;
  }

  .about-photo {
    width: 240px;
    height: 300px;
  }
}

@media (max-width: 768px) {
  :root {
    --space-lg: 1.5rem;
    --space-xl: 2.5rem;
    --space-2xl: 4rem;
    --space-3xl: 5rem;
    --nav-height: 60px;
  }

  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: center;
    padding: var(--space-xl) 0;
    background: #111118;
    border-bottom: 1px solid var(--color-border);
    gap: var(--space-md);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.3s var(--ease-out), opacity 0.3s var(--ease-out);
    z-index: 999;
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .nav-links a {
    font-size: 1rem;
    padding: var(--space-xs) 0;
  }

  .nav-toggle {
    display: flex;
  }
}

.gateway-grid {
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

.gateway-card {
  aspect-ratio: 3/4;
}

.case-images--two,
.case-images--three {
  grid-template-columns: 1fr;
}

.about-hero {
  grid-template-columns: 1fr;
  text-align: center;
}

.about-photo {
  width: 200px;
  height: 260px;
  margin: 0 auto;
}

.contact-row {
  flex-direction: column;
  align-items: flex-start;
}

.panoramic-track {
  height: 280px;
}

.footer-content {
  flex-direction: column;
  text-align: center;
}

/* Add horizontal padding on narrow screens */
.hero-content {
  padding: 0 var(--space-md);
}

.page-header .container,
.case-study {
  padding-left: var(--space-md);
  padding-right: var(--space-md);
}

.panoramic-scroll {
  padding-left: var(--space-md);
  padding-right: var(--space-md);
}

.synopsis-panel {
  margin-left: var(--space-md);
  margin-right: var(--space-md);
}

.assets-grid {
  padding: 0 var(--space-md);
}
}