/* ============================================
   YICHEN Precision Mold — B2B Industrial
   Design System: Deep Blue + Orange CTA
   ============================================ */

:root {
  --blue-deep: #1A3C6D;
  --blue-mid: #2B5EA7;
  --blue-light: #E8F0FA;
  --orange: #FF6B35;
  --orange-hover: #E55A2B;
  --white: #FFFFFF;
  --gray-50: #F8F9FB;
  --gray-100: #EEF1F5;
  --gray-200: #DDE1E7;
  --gray-400: #8B95A5;
  --gray-600: #5A6475;
  --gray-800: #2D3545;
  --gray-900: #1A1F2B;
  --radius: 8px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow: 0 4px 20px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.12);
  --transition: 0.25s ease;
}

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

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--gray-800);
  background: var(--white);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ========== Navigation ========== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--gray-100);
  transition: var(--transition);
}

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

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.logo-mark {
  background: var(--blue-deep);
  color: var(--white);
  padding: 4px 10px;
  border-radius: 4px;
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.05em;
}

.logo-text {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--blue-deep);
  letter-spacing: 0.08em;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 32px;
  align-items: center;
}

.nav-links a {
  text-decoration: none;
  color: var(--gray-600);
  font-size: 0.9rem;
  font-weight: 500;
  transition: var(--transition);
}

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

.nav-cta {
  background: var(--orange) !important;
  color: var(--white) !important;
  padding: 10px 22px !important;
  border-radius: var(--radius) !important;
  font-weight: 600 !important;
}

.nav-cta:hover {
  background: var(--orange-hover) !important;
  color: var(--white) !important;
}

.mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.mobile-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--gray-800);
  transition: var(--transition);
}

/* ========== Hero ========== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: linear-gradient(160deg, var(--blue-deep) 0%, #0F2645 50%, #0A1A33 100%);
  overflow: hidden;
  padding: 120px 0 80px;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(43,94,167,0.4) 0%, transparent 70%);
  border-radius: 50%;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(255,107,53,0.15) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.5;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.hero-eyebrow {
  color: var(--orange);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 20px;
}

.hero-title {
  color: var(--white);
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 24px;
  max-width: 800px;
}

.hero-accent {
  color: var(--orange);
}

.hero-sub {
  color: rgba(255,255,255,0.7);
  font-size: 1.15rem;
  line-height: 1.7;
  max-width: 640px;
  margin-bottom: 40px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 60px;
}

.hero-stats {
  display: flex;
  gap: 48px;
  flex-wrap: wrap;
}

.hero-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.hero-stat strong {
  color: var(--white);
  font-size: 1.8rem;
  font-weight: 700;
}

.hero-stat span {
  color: rgba(255,255,255,0.5);
  font-size: 0.85rem;
}

/* ========== Buttons ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
  white-space: nowrap;
}

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

.btn-primary:hover {
  background: var(--orange-hover);
  transform: translateY(-1px);
  box-shadow: 0 6px 24px rgba(255,107,53,0.35);
}

.btn-ghost {
  background: rgba(255,255,255,0.1);
  color: var(--white);
  border: 1px solid rgba(255,255,255,0.2);
}

.btn-ghost:hover {
  background: rgba(255,255,255,0.18);
  border-color: rgba(255,255,255,0.4);
}

.btn-outline {
  background: transparent;
  color: var(--blue-deep);
  border: 2px solid var(--blue-deep);
}

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

.btn-full {
  width: 100%;
}

/* ========== Trust Bar ========== */
.trust-bar {
  background: var(--white);
  border-bottom: 1px solid var(--gray-100);
  padding: 28px 0;
}

.trust-items {
  display: flex;
  justify-content: center;
  gap: 48px;
  flex-wrap: wrap;
}

.trust-item {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--gray-600);
  font-size: 0.9rem;
  font-weight: 500;
}

.trust-icon {
  width: 22px;
  height: 22px;
  color: var(--blue-mid);
  flex-shrink: 0;
}

/* ========== Sections ========== */
.section {
  padding: 100px 0;
}

.section-alt {
  background: var(--gray-50);
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-eyebrow {
  color: var(--orange);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(2rem, 3.5vw, 2.8rem);
  font-weight: 800;
  color: var(--gray-900);
  margin-bottom: 16px;
}

.section-desc {
  color: var(--gray-600);
  font-size: 1.1rem;
  max-width: 640px;
  margin: 0 auto;
  line-height: 1.7;
}

.section-footer {
  text-align: center;
  margin-top: 48px;
}

/* ========== Capabilities ========== */
.capabilities-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.capability-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.capability-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.capability-img {
  height: 160px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.capability-img svg {
  width: 64px;
  height: 64px;
}

.capability-body {
  padding: 28px;
}

.capability-body h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 10px;
}

.capability-body p {
  color: var(--gray-600);
  font-size: 0.95rem;
  margin-bottom: 16px;
}

.capability-body ul {
  list-style: none;
  padding: 0;
}

.capability-body li {
  font-size: 0.88rem;
  color: var(--gray-600);
  padding: 4px 0;
  padding-left: 18px;
  position: relative;
}

.capability-body li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 11px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--blue-mid);
}

/* ========== Industries ========== */
.industries-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.industry-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  border: 1px solid var(--gray-100);
}

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

.industry-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  color: var(--blue-mid);
}

.industry-icon svg {
  width: 100%;
  height: 100%;
}

.industry-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 10px;
}

.industry-card p {
  font-size: 0.88rem;
  color: var(--gray-600);
  line-height: 1.6;
}

/* ========== Why Us ========== */
.why-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.why-card {
  padding: 32px 24px;
  border-left: 3px solid var(--orange);
  background: var(--white);
  border-radius: 0 var(--radius) var(--radius) 0;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

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

.why-number {
  font-size: 2rem;
  font-weight: 800;
  color: var(--orange);
  opacity: 0.25;
  margin-bottom: 12px;
}

.why-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 10px;
}

.why-card p {
  font-size: 0.9rem;
  color: var(--gray-600);
  line-height: 1.6;
}

/* ========== Case Studies ========== */
.cases-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.case-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow);
  border-top: 4px solid var(--blue-deep);
  transition: var(--transition);
}

.case-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.case-tag {
  display: inline-block;
  background: var(--blue-light);
  color: var(--blue-deep);
  font-size: 0.78rem;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 20px;
  margin-bottom: 16px;
}

.case-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 12px;
}

.case-card p {
  font-size: 0.9rem;
  color: var(--gray-600);
  line-height: 1.6;
  margin-bottom: 20px;
}

.case-metrics {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.case-metrics span {
  font-size: 0.82rem;
  color: var(--gray-600);
}

.case-metrics strong {
  color: var(--blue-deep);
  display: block;
  font-size: 0.95rem;
}

/* ========== Quality ========== */
.quality-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.quality-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--gray-100);
  transition: var(--transition);
}

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

.quality-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 10px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--orange);
}

.quality-card p {
  font-size: 0.9rem;
  color: var(--gray-600);
  line-height: 1.6;
}

/* ========== About ========== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-content .section-title {
  font-size: 2.2rem;
}

.about-content p {
  color: var(--gray-600);
  font-size: 0.95rem;
  line-height: 1.8;
  margin-bottom: 16px;
}

.about-stats {
  display: flex;
  gap: 32px;
  margin-top: 32px;
  flex-wrap: wrap;
}

.about-stats div {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.about-stats strong {
  font-size: 1.6rem;
  color: var(--blue-deep);
}

.about-stats span {
  font-size: 0.82rem;
  color: var(--gray-400);
}

.about-image-placeholder {
  background: linear-gradient(135deg, var(--blue-deep), #0F2645);
  border-radius: var(--radius-lg);
  padding: 40px;
  text-align: center;
}

.about-image-placeholder svg {
  width: 100%;
  height: auto;
  max-height: 260px;
}

.about-image-placeholder p {
  color: rgba(255,255,255,0.5);
  font-size: 0.82rem;
  margin-top: 16px;
}

/* ========== CTA Section ========== */
.cta-section {
  background: linear-gradient(160deg, var(--blue-deep) 0%, #0F2645 100%);
  padding: 100px 0;
  position: relative;
  overflow: hidden;
}

.cta-section::before {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(255,107,53,0.2) 0%, transparent 70%);
  border-radius: 50%;
}

.cta-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
  position: relative;
  z-index: 1;
}

.cta-content h2 {
  color: var(--white);
  font-size: 2.4rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
}

.cta-content > p {
  color: rgba(255,255,255,0.65);
  font-size: 1.05rem;
  line-height: 1.7;
  margin-bottom: 32px;
}

.cta-features {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.cta-feature {
  display: flex;
  align-items: center;
  gap: 12px;
  color: rgba(255,255,255,0.8);
  font-size: 0.95rem;
}

.cta-feature svg {
  width: 20px;
  height: 20px;
  color: var(--orange);
  flex-shrink: 0;
}

/* ========== Form ========== */
.cta-form {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 40px;
  box-shadow: var(--shadow-lg);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--gray-800);
  margin-bottom: 6px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  font-family: 'Inter', sans-serif;
  font-size: 0.9rem;
  color: var(--gray-800);
  transition: var(--transition);
  background: var(--white);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--blue-mid);
  box-shadow: 0 0 0 3px rgba(43,94,167,0.1);
}

.file-upload-area {
  border: 2px dashed var(--gray-200);
  border-radius: var(--radius);
  padding: 32px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
}

.file-upload-area:hover {
  border-color: var(--blue-mid);
  background: var(--blue-light);
}

.file-upload-area svg {
  width: 32px;
  height: 32px;
  color: var(--gray-400);
  margin-bottom: 8px;
}

.file-upload-area span {
  display: block;
  font-size: 0.88rem;
  color: var(--gray-600);
}

.file-hint {
  font-size: 0.78rem !important;
  color: var(--gray-400) !important;
  margin-top: 4px;
}

.form-note {
  text-align: center;
  font-size: 0.8rem;
  color: var(--gray-400);
  margin-top: 16px;
}

/* ========== Footer ========== */
.footer {
  background: var(--gray-900);
  color: rgba(255,255,255,0.6);
  padding: 64px 0 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}

.footer-brand p {
  margin-top: 16px;
  font-size: 0.9rem;
  line-height: 1.6;
}

.footer-links h4 {
  color: var(--white);
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 16px;
}

.footer-links ul {
  list-style: none;
}

.footer-links li {
  margin-bottom: 8px;
}

.footer-links a {
  color: rgba(255,255,255,0.5);
  text-decoration: none;
  font-size: 0.88rem;
  transition: var(--transition);
}

.footer-links a:hover {
  color: var(--orange);
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 24px;
  font-size: 0.82rem;
}

/* ========== Responsive ========== */
@media (max-width: 1024px) {
  .capabilities-grid { grid-template-columns: 1fr; }
  .industries-grid { grid-template-columns: repeat(2, 1fr); }
  .why-grid { grid-template-columns: repeat(2, 1fr); }
  .cases-grid { grid-template-columns: 1fr; }
  .quality-grid { grid-template-columns: repeat(2, 1fr); }
  .about-grid { grid-template-columns: 1fr; gap: 40px; }
  .cta-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: var(--white);
    padding: 24px;
    gap: 16px;
    border-bottom: 1px solid var(--gray-100);
    box-shadow: var(--shadow);
  }
  .mobile-toggle { display: flex; }

  .hero-stats { gap: 24px; }
  .hero-stat strong { font-size: 1.4rem; }

  .trust-items { gap: 24px; }

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

  .about-stats { gap: 20px; }

  .cta-content h2 { font-size: 1.8rem; }
  .cta-form { padding: 24px; }

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

  .footer-grid { grid-template-columns: 1fr; gap: 32px; }

  .section { padding: 64px 0; }
  .cta-section { padding: 64px 0; }
}