/* ============================================================
   Lin Pure - Computer Systems Design
   Pure Code. Clear Vision. Solid Systems.
   ============================================================ */

/* --- CSS Custom Properties --- */
:root {
  --color-primary: #0891b2;
  --color-primary-dark: #0e7490;
  --color-primary-light: #22d3ee;
  --color-secondary: #d946ef;
  --color-secondary-dark: #c026d3;
  --color-bg: #ffffff;
  --color-surface: #f8fafc;
  --color-heading: #0f172a;
  --color-body: #334155;
  --color-muted: #64748b;
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', Consolas, monospace;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 12px 40px rgba(15, 23, 42, 0.08);
  --max-width: 1200px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-body);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--color-primary-dark);
}

ul {
  list-style: none;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  color: var(--color-heading);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(2.5rem, 5vw, 3.75rem); }
h2 { font-size: clamp(2rem, 4vw, 2.75rem); }
h3 { font-size: clamp(1.25rem, 2.5vw, 1.5rem); }
h4 { font-size: 1.125rem; }

.section-label {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-primary);
  margin-bottom: 0.75rem;
}

.section-title {
  margin-bottom: 1rem;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--color-muted);
  max-width: 640px;
}

/* --- Layout --- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 6rem 0;
}

.section-header {
  text-align: center;
  margin-bottom: 4rem;
}

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

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border-light);
  height: 72px;
  transition: box-shadow 0.3s ease;
}

.nav.scrolled {
  box-shadow: var(--shadow-md);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  font-size: 1.375rem;
  font-weight: 800;
  color: var(--color-heading);
  letter-spacing: -0.03em;
}

.nav-brand-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  font-size: 1.125rem;
}

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

.nav-links a {
  color: var(--color-body);
  font-size: 0.9375rem;
  font-weight: 500;
  transition: color 0.2s ease;
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 0.5rem;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-heading);
  border-radius: 2px;
  transition: all 0.3s ease;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  font-size: 1rem;
  font-weight: 600;
  font-family: var(--font-sans);
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all 0.25s ease;
  text-align: center;
}

.btn-primary {
  background: var(--color-primary);
  color: #ffffff;
  border-color: var(--color-primary);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  color: #ffffff;
}

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-outline:hover {
  background: var(--color-primary);
  color: #ffffff;
}

.btn-white {
  background: #ffffff;
  color: var(--color-primary);
  border-color: #ffffff;
}

.btn-white:hover {
  background: #f1f5f9;
  border-color: #f1f5f9;
  color: var(--color-primary-dark);
}

.btn-lg {
  padding: 1rem 2.25rem;
  font-size: 1.0625rem;
}

/* --- Hero --- */
.hero {
  padding: 10rem 0 6rem;
  background: linear-gradient(180deg, #ffffff 0%, var(--color-surface) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(8, 145, 178, 0.06) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -15%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(217, 70, 239, 0.04) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 560px;
}

.hero h1 {
  margin-bottom: 1.25rem;
  line-height: 1.15;
}

.hero-highlight {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.1875rem;
  color: var(--color-muted);
  margin-bottom: 2rem;
  line-height: 1.6;
}

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

.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 420px;
}

.hero-card-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: 100px;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-body);
  margin-bottom: 1.5rem;
}

.hero-card-pill .dot {
  width: 8px;
  height: 8px;
  background: #22c55e;
  border-radius: 50%;
  display: inline-block;
}

.hero-card h3 {
  font-size: 1.375rem;
  margin-bottom: 1.25rem;
}

.hero-card-features {
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
}

.hero-card-features li {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  font-size: 0.9375rem;
}

.hero-card-features .icon {
  color: var(--color-primary);
  flex-shrink: 0;
  margin-top: 1px;
}

/* --- About --- */
.about {
  background: var(--color-bg);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.about-text p {
  margin-bottom: 1.25rem;
}

.about-text p:last-child {
  margin-bottom: 0;
}

.about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.stat-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  padding: 2rem;
  text-align: center;
}

.stat-number {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: 0.5rem;
}

.stat-label {
  font-size: 0.9375rem;
  color: var(--color-muted);
  font-weight: 500;
}

/* --- Services --- */
.services {
  background: var(--color-surface);
}

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

.service-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  padding: 2rem;
  transition: box-shadow 0.3s ease, border-color 0.3s ease;
}

.service-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-border);
}

.service-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  font-size: 1.5rem;
}

.service-icon.cyan { background: #ecfeff; color: #0891b2; }
.service-icon.fuchsia { background: #fdf4ff; color: #d946ef; }
.service-icon.blue { background: #eff6ff; color: #3b82f6; }
.service-icon.amber { background: #fffbeb; color: #d97706; }
.service-icon.emerald { background: #ecfdf5; color: #059669; }
.service-icon.rose { background: #fff1f2; color: #e11d48; }

.service-card h3 {
  margin-bottom: 0.75rem;
}

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

/* --- Industries --- */
.industries {
  background: var(--color-bg);
}

.industries-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}

.industry-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
  transition: all 0.3s ease;
}

.industry-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.industry-icon {
  font-size: 2rem;
  margin-bottom: 0.75rem;
}

.industry-card h4 {
  color: var(--color-heading);
  font-size: 1rem;
  margin-bottom: 0.375rem;
}

.industry-card p {
  font-size: 0.8125rem;
  color: var(--color-muted);
  line-height: 1.5;
}

/* --- Process --- */
.process {
  background: var(--color-surface);
}

.process-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  position: relative;
}

.process-steps::before {
  content: '';
  position: absolute;
  top: 40px;
  left: 12.5%;
  right: 12.5%;
  height: 2px;
  background: var(--color-border);
  z-index: 0;
}

.process-step {
  text-align: center;
  position: relative;
  z-index: 1;
  padding: 0 1rem;
}

.step-number {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: var(--color-bg);
  border: 3px solid var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--color-primary);
}

.process-step h3 {
  margin-bottom: 0.625rem;
}

.process-step p {
  font-size: 0.9375rem;
  color: var(--color-muted);
  line-height: 1.6;
}

/* --- Capabilities --- */
.capabilities {
  background: var(--color-bg);
}

.cap-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}

.cap-category {
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  padding: 1.75rem;
}

.cap-category h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.cap-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.cap-tag {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-body);
  background: var(--color-bg);
  border: 1px solid var(--color-border-light);
  border-radius: 100px;
  transition: all 0.2s ease;
}

.cap-tag:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* --- Why Lin Pure --- */
.why-us {
  background: var(--color-surface);
}

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

.why-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  padding: 2rem;
  transition: box-shadow 0.3s ease;
}

.why-card:hover {
  box-shadow: var(--shadow-md);
}

.why-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  font-size: 1.5rem;
  background: #ecfeff;
  color: #0891b2;
}

.why-card h3 {
  margin-bottom: 0.75rem;
}

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

/* --- Contact --- */
.contact {
  background: var(--color-bg);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 4rem;
  align-items: start;
}

.contact-info h2 {
  margin-bottom: 1rem;
}

.contact-info > p {
  color: var(--color-muted);
  margin-bottom: 2rem;
}

.contact-details {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.contact-detail {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.contact-detail-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: #ecfeff;
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 1.125rem;
}

.contact-detail h4 {
  margin-bottom: 0.25rem;
  font-size: 0.9375rem;
}

.contact-detail p {
  font-size: 0.9375rem;
  color: var(--color-muted);
}

.contact-form {
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--color-heading);
  margin-bottom: 0.5rem;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  font-family: var(--font-sans);
  color: var(--color-body);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(8, 145, 178, 0.1);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

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

/* --- CTA Banner --- */
.cta-banner {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  padding: 5rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-banner::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 50%, rgba(217, 70, 239, 0.15) 0%, transparent 50%);
  pointer-events: none;
}

.cta-banner-inner {
  position: relative;
  z-index: 1;
}

.cta-banner h2 {
  color: #ffffff;
  margin-bottom: 1rem;
}

.cta-banner p {
  color: #cffafe;
  font-size: 1.125rem;
  margin-bottom: 2rem;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

.cta-banner .btn-white {
  font-size: 1.0625rem;
}

/* --- Footer --- */
.footer {
  background: var(--color-heading);
  color: #cbd5e1;
  padding: 4rem 0 2rem;
}

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

.footer-brand {
  font-size: 1.375rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 1rem;
}

.footer-about p {
  font-size: 0.9375rem;
  line-height: 1.7;
  color: #94a3b8;
}

.footer-col h4 {
  color: #ffffff;
  font-size: 0.9375rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-col a {
  color: #94a3b8;
  font-size: 0.9375rem;
  transition: color 0.2s ease;
}

.footer-col a:hover {
  color: #ffffff;
}

.footer-bottom {
  border-top: 1px solid #334155;
  padding-top: 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.875rem;
  color: #64748b;
}

/* --- Mobile Menu --- */
.mobile-menu {
  display: none;
  position: fixed;
  top: 72px;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-bg);
  z-index: 999;
  padding: 2rem 1.5rem;
  flex-direction: column;
  gap: 1.5rem;
}

.mobile-menu.active {
  display: flex;
}

.mobile-menu a {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-heading);
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--color-border-light);
}

/* --- Legal Pages --- */
.legal-page {
  padding: 8rem 0 4rem;
}

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

.legal-content h1 {
  margin-bottom: 0.5rem;
}

.legal-content .last-updated {
  color: var(--color-muted);
  font-size: 0.9375rem;
  margin-bottom: 2.5rem;
}

.legal-content h2 {
  font-size: 1.375rem;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
}

.legal-content p {
  margin-bottom: 1rem;
  line-height: 1.7;
}

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

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

.legal-content address {
  font-style: normal;
  margin-bottom: 1.5rem;
  line-height: 1.7;
}

/* --- Toast / Form Feedback --- */
.toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--color-heading);
  color: #ffffff;
  padding: 1rem 1.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.9375rem;
  font-weight: 500;
  z-index: 2000;
  box-shadow: var(--shadow-lg);
  animation: slideUp 0.3s ease;
}

.toast.success {
  background: #059669;
}

.toast.error {
  background: #dc2626;
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

  .industries-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .process-steps::before {
    display: none;
  }

  .cap-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .why-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .hero-visual {
    order: -1;
  }

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

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

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

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

  .nav-links {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

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

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

  .industries-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .section {
    padding: 4rem 0;
  }

  .hero {
    padding: 8rem 0 4rem;
  }
}

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

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

  .hero-actions {
    flex-direction: column;
  }
}