/* ============================================================
   Andrew Yuan - Personal Site - Stylesheet
   Cinematic, project-focused with living portfolio effects.
   ============================================================ */

/* === CUSTOM PROPERTIES ====================================== */
:root {
  /* Dark palette (default) */
  --color-bg:         #0c0a09;
  --color-surface:    #1c1917;
  --color-text:       #fafaf9;
  --color-text-muted: #a8a29e;
  --color-accent:     #60a5fa;
  --color-accent-hover:#93c5fd;
  --color-border:     #292524;
  --color-surface-alt:#1c1917;
  --color-glow:       rgba(96, 165, 250, 0.06);
  --shadow-card:      0 2px 24px rgba(0,0,0,0.2);
  --shadow-card-hover:0 12px 48px rgba(0,0,0,0.4);

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

  /* Typography */
  --font-body: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --duration: 0.35s;
}

/* === RESET & BASE =========================================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

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

body {
  font-family: var(--font-body);
  font-size: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  overflow-x: hidden;
}

img { display: block; max-width: 100%; }
a   { color: inherit; text-decoration: none; }

/* === CURSOR GLOW ============================================ */
.cursor-glow {
  position: fixed;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  pointer-events: none;
  z-index: 9999;
  background: radial-gradient(circle, var(--color-glow), transparent 70%);
  transform: translate(-50%, -50%);
  opacity: 0;
  transition: opacity 0.4s;
  will-change: left, top;
}

@media (hover: none) {
  .cursor-glow { display: none; }
}

/* === FILM GRAIN ============================================= */
.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 9998;
  opacity: 0.035;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-size: 200px;
}

@media (prefers-color-scheme: dark) {
  .grain { mix-blend-mode: screen; opacity: 0.04; }
}

/* === CONTAINER ============================================== */
.container {
  width: 100%;
  max-width: 72rem;
  margin-inline: auto;
  padding-inline: var(--space-md);
}

/* === NAVIGATION ============================================= */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: color-mix(in srgb, var(--color-bg) 80%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: transform var(--duration) var(--ease-out);
}

.nav.hidden { transform: translateY(-100%); }

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 72rem;
  margin-inline: auto;
  padding: var(--space-sm) var(--space-md);
}

.nav-logo {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--color-accent);
}

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

.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  transition: color var(--duration);
}

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

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 2rem;
  height: 1.5rem;
  position: relative;
}

.nav-toggle span {
  display: block;
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  transition: var(--duration) var(--ease-out);
}

.nav-toggle span:nth-child(1) { top: 0; }
.nav-toggle span:nth-child(2) { top: 50%; transform: translateY(-50%); }
.nav-toggle span:nth-child(3) { bottom: 0; }

@media (max-width: 768px) {
  .nav-toggle { display: block; }
  .nav-links {
    position: fixed;
    inset: 0;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--space-lg);
    background: var(--color-bg);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--duration);
  }
  .nav-links.open {
    opacity: 1;
    pointer-events: auto;
  }
  .nav-links a { font-size: 1.25rem; }
}

/* === HERO =================================================== */
.hero {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: var(--space-xl) var(--space-md);
  text-align: center;
  position: relative;
}

.hero-content { max-width: 48rem; }

.hero-greeting {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--color-accent);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: var(--space-xs);
}

.hero-name {
  font-size: clamp(2.5rem, 5vw + 1rem, 5rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-xs);
}

.hero-title {
  font-size: clamp(1.125rem, 1rem + 0.5vw, 1.5rem);
  font-weight: 300;
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
}

.hero-tagline {
  font-family: var(--font-mono);
  font-size: clamp(0.875rem, 0.8rem + 0.35vw, 1.125rem);
  color: var(--color-accent);
  margin-bottom: var(--space-lg);
  min-height: 1.6em;
}

/* Typing cursor */
.hero-tagline .typed-cursor {
  display: inline-block;
  width: 2px;
  height: 1.1em;
  background: var(--color-accent);
  margin-left: 2px;
  vertical-align: text-bottom;
  animation: blink 0.8s step-end infinite;
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50%      { opacity: 0; }
}

/* CTA Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 1.75rem;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 500;
  border-radius: 6px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--duration) var(--ease-out);
}

.btn-primary {
  background: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent);
}
.btn-primary:hover {
  background: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px color-mix(in srgb, var(--color-accent) 30%, transparent);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border);
}
.btn-ghost:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: translateY(-1px);
}

.hero-cta {
  display: flex;
  gap: var(--space-sm);
  justify-content: center;
  flex-wrap: wrap;
}

/* Scroll indicator */
.hero-scroll {
  position: absolute;
  bottom: var(--space-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.hero-scroll-text {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

.hero-scroll-line {
  width: 1px;
  height: 3rem;
  background: var(--color-border);
  animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {
  0%, 100% { opacity: 0.3; transform: scaleY(0.5); }
  50%      { opacity: 1;   transform: scaleY(1);   }
}

/* === SECTIONS =============================================== */
.section {
  padding: var(--space-xl) 0;
}

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

.section-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
}

.section-heading {
  font-size: clamp(1.75rem, 1.5rem + 1vw, 2.75rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-lg);
}

/* === WORK / PROJECTS - CINEMATIC ============================ */
.work-intro {
  color: var(--color-text-muted);
  margin-bottom: var(--space-lg);
  max-width: 40rem;
}

/* Full-width cinematic featured cards */
.project-cinema {
  width: 100%;
  max-width: 72rem;
  margin-inline: auto;
  padding: 0 var(--space-md);
  margin-bottom: var(--space-md);
  perspective: 1200px;
}

.project-hero {
  display: block;
  position: relative;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--shadow-card);
  transition: box-shadow 0.5s var(--ease-out), transform 0.5s var(--ease-out);
  transform-style: preserve-3d;
  will-change: transform;
}

.project-hero:hover {
  box-shadow: var(--shadow-card-hover);
}

.project-hero-img {
  position: relative;
  aspect-ratio: 21 / 9;
  overflow: hidden;
}

.project-hero-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.7s var(--ease-out);
}

.project-hero:hover .project-hero-img img {
  transform: scale(1.03);
}

.project-hero-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: flex-end;
  background: linear-gradient(
    to top,
    rgba(0, 0, 0, 0.92) 0%,
    rgba(0, 0, 0, 0.75) 35%,
    rgba(0, 0, 0, 0.35) 70%,
    rgba(0, 0, 0, 0.1) 100%
  );
  padding: var(--space-lg);
  transition: background 0.5s;
}

.project-hero:hover .project-hero-overlay {
  background: linear-gradient(
    to top,
    rgba(0, 0, 0, 0.95) 0%,
    rgba(0, 0, 0, 0.8) 35%,
    rgba(0, 0, 0, 0.4) 70%,
    rgba(0, 0, 0, 0.15) 100%
  );
}

.project-hero-content {
  max-width: 36rem;
  color: #fff;
}

.project-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-xs);
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  padding: 0.25rem 0.75rem;
  border-radius: 100px;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.project-hero-content h3 {
  font-size: clamp(1.5rem, 1.25rem + 1vw, 2.25rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.6);
}

.project-hero-content p {
  font-size: 0.9375rem;
  color: rgba(255, 255, 255, 0.82);
  line-height: 1.6;
  margin-bottom: var(--space-sm);
  max-width: 32rem;
  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.5);
}

.project-cta {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--color-accent);
  letter-spacing: 0.02em;
  transition: letter-spacing var(--duration), color var(--duration);
}

.project-hero:hover .project-cta {
  letter-spacing: 0.06em;
  color: var(--color-accent-hover);
}

@media (max-width: 768px) {
  .project-hero-img { aspect-ratio: 16 / 10; }
  .project-hero-overlay { padding: var(--space-md); }
  .project-hero-content h3 { font-size: 1.25rem; }
}

/* Secondary project cards - 2-column grid with images */
.project-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
  margin-top: var(--space-md);
  perspective: 1200px;
}

.project-card {
  display: block;
  border-radius: 12px;
  overflow: hidden;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-card);
  transition: box-shadow 0.5s var(--ease-out), transform 0.5s var(--ease-out), border-color 0.3s;
  transform-style: preserve-3d;
  will-change: transform;
}

.project-card:hover {
  box-shadow: var(--shadow-card-hover);
  border-color: var(--color-accent);
}

.project-card-img {
  aspect-ratio: 16 / 10;
  overflow: hidden;
}

.project-card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.7s var(--ease-out);
}

.project-card:hover .project-card-img img {
  transform: scale(1.05);
}

.project-card-body {
  padding: var(--space-md);
}

.project-card-body .project-badge {
  color: var(--color-accent);
  background: color-mix(in srgb, var(--color-accent) 8%, transparent);
  border-color: color-mix(in srgb, var(--color-accent) 20%, transparent);
}

.project-card h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.project-card p {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: var(--space-sm);
}

.project-card .project-cta {
  color: var(--color-accent);
}

.project-card:hover .project-cta {
  letter-spacing: 0.06em;
}

@media (max-width: 640px) {
  .project-grid { grid-template-columns: 1fr; }
}

/* === ABOUT ================================================== */
.about-compact {
  max-width: 42rem;
}

.about-heading {
  font-size: clamp(1.5rem, 1.25rem + 1vw, 2.25rem);
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: var(--space-md);
}

.about-text {
  color: var(--color-text-muted);
  line-height: 1.8;
}

/* === FOCUS ================================================== */
.focus-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

.focus-card {
  padding: var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  transition: border-color var(--duration), box-shadow var(--duration), transform 0.5s var(--ease-out);
}

.focus-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 1px var(--color-accent);
  transform: translateY(-2px);
}

.focus-icon {
  width: 3rem;
  height: 3rem;
  display: grid;
  place-items: center;
  background: color-mix(in srgb, var(--color-accent) 10%, transparent);
  border-radius: 8px;
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
}

.focus-card h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.focus-card p {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}

@media (max-width: 640px) {
  .focus-grid { grid-template-columns: 1fr; }
}

/* === IMPACT ================================================= */
.impact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

.impact-item {
  padding: var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  text-align: center;
  transition: border-color var(--duration), transform 0.4s var(--ease-out);
}

.impact-item:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
}

.impact-metric {
  display: block;
  font-size: clamp(1.75rem, 1.5rem + 1vw, 2.5rem);
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: 0.5rem;
}

.impact-description {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.5;
}

@media (max-width: 768px) {
  .impact-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 480px) {
  .impact-grid { grid-template-columns: 1fr; }
}

/* === CONNECT ================================================ */
.connect-section { text-align: center; }

.connect-text {
  color: var(--color-text-muted);
  max-width: 36rem;
  margin-inline: auto;
  margin-bottom: var(--space-lg);
}

.connect-links {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.connect-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 1.5rem;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: all var(--duration) var(--ease-out);
}

.connect-link:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: translateY(-2px);
}

/* === FOOTER ================================================= */
.footer {
  padding: var(--space-md) 0;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.8125rem;
  border-top: 1px solid var(--color-border);
}

/* === ANIMATIONS ============================================= */
.fade-in {
  opacity: 0;
  transform: translateY(2rem);
  transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger children */
.fade-in.visible > *:nth-child(1) { transition-delay: 0.05s; }
.fade-in.visible > *:nth-child(2) { transition-delay: 0.10s; }
.fade-in.visible > *:nth-child(3) { transition-delay: 0.15s; }
.fade-in.visible > *:nth-child(4) { transition-delay: 0.20s; }
.fade-in.visible > *:nth-child(5) { transition-delay: 0.25s; }
.fade-in.visible > *:nth-child(6) { transition-delay: 0.30s; }

/* Selection */
::selection {
  background: color-mix(in srgb, var(--color-accent) 20%, transparent);
  color: var(--color-text);
}