/* ============================================================
   Ruo Sheng — Bauhaus Bold Primary Design System
   ############################################################ */

/* --- CSS Custom Properties --- */
:root {
  --white: #FAFAFA;
  --red: #DC2626;
  --yellow: #F59E0B;
  --blue: #2563EB;
  --text: #111827;
  --footer: #1F2937;
  --alt: #F3F4F6;
  --red-dark: #B91C1C;
  --yellow-dark: #D97706;
  --blue-dark: #1D4ED8;

  --font-sans: 'Inter', 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  --max-width: 1200px;
  --header-h: 72px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  background: var(--white);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

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

ul {
  list-style: none;
}

/* --- Utility --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}

/* --- Geometric Decor Elements --- */
.geo-circle {
  border-radius: 50%;
  position: absolute;
  pointer-events: none;
}

.geo-square {
  position: absolute;
  pointer-events: none;
  transform: rotate(15deg);
}

.geo-dot {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
}

/* ============================================================
   HEADER / NAVIGATION
   ############################################################ */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-h);
  background: var(--white);
  border-bottom: 4px solid var(--text);
  z-index: 1000;
  display: flex;
  align-items: center;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--text);
  letter-spacing: -0.02em;
}

.logo svg {
  width: 40px;
  height: 40px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-links a {
  font-weight: 700;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.25rem 0;
  border-bottom: 3px solid transparent;
  transition: border-color 0.2s;
  color: var(--text);
}

.nav-links a:hover,
.nav-links a:focus-visible {
  border-bottom-color: var(--red);
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  z-index: 1001;
}

.hamburger span {
  display: block;
  width: 28px;
  height: 3px;
  background: var(--text);
  transition: transform 0.3s, opacity 0.3s;
}

.hamburger.active span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

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

.hamburger.active span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* ============================================================
   SECTION 1 — HERO (Red Band)
   ############################################################ */

.hero {
  position: relative;
  background: var(--red);
  color: var(--white);
  padding: 140px 0 100px;
  overflow: hidden;
  min-height: 90vh;
  display: flex;
  align-items: center;
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
  position: relative;
  z-index: 2;
}

.hero-badge {
  display: inline-block;
  background: var(--white);
  color: var(--red);
  font-weight: 800;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 0.4rem 1rem;
  margin-bottom: 1.5rem;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 1.5rem;
}

.hero h1 span {
  display: inline-block;
  background: var(--yellow);
  color: var(--text);
  padding: 0 0.2em;
}

.hero p {
  font-size: 1.2rem;
  opacity: 0.9;
  max-width: 480px;
  margin-bottom: 2rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  font-weight: 800;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.9rem 2rem;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn:hover {
  transform: translate(-2px, -2px);
  box-shadow: 4px 4px 0 rgba(0,0,0,0.15);
}

.btn-primary {
  background: var(--text);
  color: var(--white);
}

.btn-secondary {
  background: var(--white);
  color: var(--text);
}

.btn-blue {
  background: var(--blue);
  color: var(--white);
}

.btn-yellow {
  background: var(--yellow);
  color: var(--text);
}

.hero-visual {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 350px;
}

.hero-visual .geo-circle {
  width: 260px;
  height: 260px;
  background: var(--yellow);
  top: 50%;
  right: 40px;
  transform: translateY(-50%);
}

.hero-visual .geo-square {
  width: 80px;
  height: 80px;
  background: var(--white);
  top: 20px;
  right: 0;
}

.hero-visual .geo-dot {
  width: 18px;
  height: 18px;
  background: var(--white);
  bottom: 40px;
  left: 40px;
}

/* Decorative background shapes */
.hero-bg-square {
  position: absolute;
  width: 120px;
  height: 120px;
  border: 4px solid rgba(255,255,255,0.15);
  transform: rotate(25deg);
  top: 15%;
  left: 5%;
  pointer-events: none;
}

.hero-bg-stripes {
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: 120px;
  display: flex;
  flex-direction: column;
  pointer-events: none;
}

.hero-bg-stripes span {
  flex: 1;
  width: 100%;
}

.hero-bg-stripes span:nth-child(1) { background: rgba(255,255,255,0.04); }
.hero-bg-stripes span:nth-child(2) { background: rgba(255,255,255,0.02); }
.hero-bg-stripes span:nth-child(3) { background: rgba(255,255,255,0.06); }
.hero-bg-stripes span:nth-child(4) { background: rgba(255,255,255,0.01); }

/* ============================================================
   SECTION 2 — COLOR METRICS
   ############################################################ */

.color-metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
}

.metric-card {
  padding: 3.5rem 2rem;
  color: var(--white);
  position: relative;
  overflow: hidden;
}

.metric-card:nth-child(1) { background: var(--red); }
.metric-card:nth-child(2) { background: var(--yellow); color: var(--text); }
.metric-card:nth-child(3) { background: var(--blue); }

.metric-number {
  font-size: 3.5rem;
  font-weight: 900;
  line-height: 1;
  display: block;
  margin-bottom: 0.5rem;
}

.metric-label {
  font-weight: 700;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  opacity: 0.8;
}

.metric-card .geo-square {
  width: 50px;
  height: 50px;
  bottom: -10px;
  right: 20px;
  opacity: 0.2;
  border: 2px solid currentColor;
}

/* ============================================================
   SECTION 3 — SERVICES
   ############################################################ */

.services {
  padding: 100px 0;
  background: var(--white);
  position: relative;
}

.services-bg-dot {
  position: absolute;
  width: 200px;
  height: 200px;
  border-radius: 50%;
  background: var(--alt);
  top: -60px;
  right: -80px;
  pointer-events: none;
}

.section-label {
  display: inline-block;
  font-weight: 800;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--red);
  margin-bottom: 0.75rem;
}

.section-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
  color: var(--text);
}

.section-subtitle {
  font-size: 1.1rem;
  color: #4B5563;
  max-width: 560px;
  margin-bottom: 3rem;
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.service-card {
  background: var(--white);
  border: 2px solid #E5E7EB;
  padding: 2rem;
  position: relative;
  transition: transform 0.25s, box-shadow 0.25s;
}

.service-card:hover {
  transform: translateY(-4px);
  box-shadow: 8px 8px 0 rgba(0,0,0,0.08);
}

.service-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 6px;
}

.service-card.accent-red::before { background: var(--red); }
.service-card.accent-yellow::before { background: var(--yellow); }
.service-card.accent-blue::before { background: var(--blue); }

.service-card-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
}

.service-card-icon svg {
  width: 32px;
  height: 32px;
}

.service-card.accent-red .service-card-icon svg { color: var(--red); }
.service-card.accent-yellow .service-card-icon svg { color: var(--yellow-dark); }
.service-card.accent-blue .service-card-icon svg { color: var(--blue); }

.service-card h3 {
  font-size: 1.2rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.service-card p {
  font-size: 1rem;
  color: #4B5563;
  line-height: 1.65;
}

/* ============================================================
   SECTION 4 — PROCESS (Alternating Color Bands)
   ############################################################ */

.process {
  padding: 100px 0;
  background: var(--white);
  position: relative;
}

.process-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0;
}

.process-step {
  padding: 3rem 2.5rem;
  position: relative;
  overflow: hidden;
}

.process-step:nth-child(odd) {
  background: #FEF2F2;
  border-left: 6px solid var(--red);
}

.process-step:nth-child(even) {
  background: #EFF6FF;
  border-left: 6px solid var(--blue);
}

.process-step-number {
  font-size: 4rem;
  font-weight: 900;
  line-height: 1;
  opacity: 0.15;
  position: absolute;
  top: 0.5rem;
  right: 1.5rem;
  color: var(--text);
}

.process-step h3 {
  font-size: 1.3rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
  color: var(--text);
  position: relative;
  z-index: 1;
}

.process-step p {
  font-size: 1rem;
  color: #4B5563;
  position: relative;
  z-index: 1;
}

.process-step .geo-dot {
  width: 12px;
  height: 12px;
  bottom: 1rem;
  left: 1.5rem;
}

.process-step:nth-child(odd) .geo-dot { background: var(--red); }
.process-step:nth-child(even) .geo-dot { background: var(--blue); }

/* ============================================================
   SECTION 5 — PORTFOLIO / SHOWCASE
   ############################################################ */

.portfolio {
  padding: 100px 0;
  background: var(--alt);
  position: relative;
}

.portfolio-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.portfolio-card {
  background: var(--white);
  border: 2px solid #E5E7EB;
  overflow: hidden;
  transition: transform 0.25s;
}

.portfolio-card:hover {
  transform: translateY(-4px);
}

.portfolio-card-image {
  height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.portfolio-card-image.red-bg { background: #FEE2E2; }
.portfolio-card-image.yellow-bg { background: #FEF3C7; }
.portfolio-card-image.blue-bg { background: #DBEAFE; }

.portfolio-card-image .geo-circle {
  width: 80px;
  height: 80px;
  opacity: 0.25;
}

.portfolio-card-image.red-bg .geo-circle { background: var(--red); }
.portfolio-card-image.yellow-bg .geo-circle { background: var(--yellow); }
.portfolio-card-image.blue-bg .geo-circle { background: var(--blue); }

.portfolio-card-image .geo-square {
  width: 40px;
  height: 40px;
  bottom: 15px;
  right: 20px;
  opacity: 0.5;
}

.portfolio-card-image.red-bg .geo-square { background: var(--red); }
.portfolio-card-image.yellow-bg .geo-square { background: var(--yellow); }
.portfolio-card-image.blue-bg .geo-square { background: var(--blue); }

.portfolio-card-body {
  padding: 1.5rem;
}

.portfolio-tag {
  display: inline-block;
  font-weight: 800;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 0.25rem 0.75rem;
  margin-bottom: 0.75rem;
}

.tag-red { background: var(--red); color: var(--white); }
.tag-yellow { background: var(--yellow); color: var(--text); }
.tag-blue { background: var(--blue); color: var(--white); }

.portfolio-card-body h3 {
  font-size: 1.1rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
  color: var(--text);
}

.portfolio-card-body p {
  font-size: 0.9rem;
  color: #6B7280;
}

/* ============================================================
   SECTION 6 — ABOUT (Blue/White Split)
   ############################################################ */

.about {
  display: grid;
  grid-template-columns: 1fr 1fr;
}

.about-left {
  background: var(--blue);
  color: var(--white);
  padding: 5rem 3rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.about-left .geo-circle {
  width: 180px;
  height: 180px;
  background: rgba(255,255,255,0.06);
  bottom: -40px;
  right: -40px;
}

.about-left .section-label {
  color: var(--yellow);
}

.about-left h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.5rem);
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 1.5rem;
}

.about-left p {
  font-size: 1rem;
  opacity: 0.9;
  line-height: 1.7;
  max-width: 460px;
}

.about-right {
  background: var(--white);
  padding: 5rem 3rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
}

.about-quote {
  font-size: 1.4rem;
  font-weight: 700;
  font-style: italic;
  line-height: 1.5;
  color: var(--text);
  margin-bottom: 1.5rem;
  position: relative;
  padding-left: 1.5rem;
  border-left: 5px solid var(--yellow);
}

.about-quote-author {
  font-weight: 800;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--blue);
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  margin-top: 2rem;
}

.about-stat {
  text-align: left;
}

.about-stat-number {
  font-size: 2rem;
  font-weight: 900;
  line-height: 1;
}

.about-stat-number.red { color: var(--red); }
.about-stat-number.yellow { color: var(--yellow-dark); }
.about-stat-number.blue { color: var(--blue); }

.about-stat-label {
  font-size: 0.85rem;
  color: #6B7280;
  margin-top: 0.25rem;
}

/* ============================================================
   SECTION 7 — CTA (Yellow Band)
   ############################################################ */

.cta {
  background: var(--yellow);
  color: var(--text);
  padding: 80px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta .geo-circle {
  width: 300px;
  height: 300px;
  border: 3px solid rgba(0,0,0,0.06);
  top: -100px;
  left: -100px;
}

.cta .geo-square {
  width: 60px;
  height: 60px;
  background: rgba(0,0,0,0.05);
  bottom: -20px;
  right: 10%;
}

.cta .container {
  position: relative;
  z-index: 2;
}

.cta h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 1rem;
}

.cta p {
  font-size: 1.15rem;
  color: #374151;
  max-width: 550px;
  margin: 0 auto 2rem;
}

/* ============================================================
   SECTION 8 — CONTACT
   ############################################################ */

.contact {
  padding: 100px 0;
  background: var(--white);
}

.contact-wrapper {
  border: 3px solid var(--blue);
  padding: 3rem;
  max-width: 700px;
  margin: 0 auto;
  position: relative;
}

.contact-wrapper .geo-square {
  width: 30px;
  height: 30px;
  background: var(--red);
  top: -15px;
  right: -15px;
}

.contact-wrapper .geo-dot {
  width: 14px;
  height: 14px;
  background: var(--yellow);
  bottom: -7px;
  left: -7px;
}

.contact-form {
  display: grid;
  gap: 1.25rem;
}

.form-group label {
  display: block;
  font-weight: 700;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 0.5rem;
  color: var(--text);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.85rem 1rem;
  border: 2px solid #E5E7EB;
  font-family: var(--font-sans);
  font-size: 1rem;
  background: var(--white);
  color: var(--text);
  transition: border-color 0.2s;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--blue);
}

.form-group textarea {
  min-height: 130px;
  resize: vertical;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

/* ============================================================
   SECTION 9 — FOOTER
   ############################################################ */

.site-footer {
  background: var(--footer);
  color: var(--white);
  padding: 60px 0 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand .logo-text {
  font-weight: 900;
  font-size: 1.5rem;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
}

.footer-brand p {
  font-size: 0.95rem;
  opacity: 0.65;
  max-width: 300px;
  line-height: 1.7;
}

.footer-col h4 {
  font-weight: 800;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1.25rem;
  color: var(--yellow);
}

.footer-col a {
  display: block;
  font-size: 0.95rem;
  opacity: 0.7;
  margin-bottom: 0.6rem;
  transition: opacity 0.2s;
}

.footer-col a:hover {
  opacity: 1;
  color: var(--yellow);
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 1.5rem;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.85rem;
  opacity: 0.5;
}

.footer-bottom a {
  color: var(--yellow);
  text-decoration: underline;
}

/* ============================================================
   ANIMATIONS (Intersection Observer)
   ############################################################ */

.animate {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

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

.animate-left {
  opacity: 0;
  transform: translateX(-40px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-left.visible {
  opacity: 1;
  transform: translateX(0);
}

.animate-right {
  opacity: 0;
  transform: translateX(40px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-right.visible {
  opacity: 1;
  transform: translateX(0);
}

.animate-scale {
  opacity: 0;
  transform: scale(0.9);
  transition: opacity 0.5s ease-out, transform 0.5s ease-out;
}

.animate-scale.visible {
  opacity: 1;
  transform: scale(1);
}

/* Stagger delays */
.delay-1 { transition-delay: 0.1s; }
.delay-2 { transition-delay: 0.2s; }
.delay-3 { transition-delay: 0.3s; }
.delay-4 { transition-delay: 0.4s; }
.delay-5 { transition-delay: 0.5s; }

/* ============================================================
   LEGAL PAGES (Privacy / Terms)
   ############################################################ */

.legal-hero {
  background: var(--blue);
  color: var(--white);
  padding: 140px 0 60px;
  position: relative;
  overflow: hidden;
}

.legal-hero .geo-circle {
  width: 250px;
  height: 250px;
  background: rgba(255,255,255,0.05);
  top: -60px;
  right: -80px;
}

.legal-hero h1 {
  font-size: clamp(2rem, 4.5vw, 3.5rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.legal-hero .section-label {
  color: var(--yellow);
}

.legal-content {
  padding: 60px 0 80px;
  background: var(--white);
}

.legal-content .container {
  max-width: 780px;
}

.legal-content h2 {
  font-size: 1.5rem;
  font-weight: 800;
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
  color: var(--text);
  padding-bottom: 0.5rem;
  border-bottom: 3px solid var(--yellow);
  display: inline-block;
}

.legal-content h2:first-of-type {
  margin-top: 0;
}

.legal-content p {
  margin-bottom: 1rem;
  line-height: 1.8;
  color: #374151;
}

.legal-content ul {
  list-style: disc;
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.legal-content li {
  margin-bottom: 0.5rem;
  line-height: 1.7;
  color: #374151;
}

/* ============================================================
   RESPONSIVE
   ############################################################ */

@media (max-width: 1024px) {
  .services-grid,
  .portfolio-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: var(--white);
    flex-direction: column;
    padding: 100px 2rem 2rem;
    gap: 1.5rem;
    transition: right 0.35s ease;
    border-left: 4px solid var(--text);
    z-index: 999;
  }

  .nav-links.active {
    right: 0;
  }

  .hamburger {
    display: flex;
  }

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

  .hero p {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-visual {
    display: none;
  }

  .color-metrics {
    grid-template-columns: 1fr;
  }

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

  .about-left,
  .about-right {
    padding: 3rem 2rem;
  }

  .services-grid,
  .portfolio-grid {
    grid-template-columns: 1fr;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .contact-wrapper {
    padding: 2rem 1.5rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .footer-bottom {
    flex-direction: column;
  }
}