/* ==========================================================================
   DIAMOND INVESTMENT GROUP - APPLE-GRADE DESIGN SYSTEM (css/style.css)
   ========================================================================== */

/* 1. DESIGN TOKENS & VARIABLES (From design.md) */
:root {
  /* Colors */
  --color-primary-ink: #1d1d1f;
  --gradient-primary-ink: linear-gradient(184deg, #1d1d1f 20%, #0f2d22 76%, #12372a 95%);
  --color-mid-gray: #707070;
  --color-deep-gray: #474747;
  --color-hairline: #d6d6d6;
  --color-canvas: #f5f5f7;
  --color-paper: #ffffff;
  --color-cool-wash: #e8e8ed;
  --color-faded-surface: #fafafc;
  --color-quiet-dot: #777779;
  --color-electric-blue: #0071e3;
  --color-link-blue: #0066cc;
  --color-ember: #b64400;
  --color-accent-gold: #d4af37;
  --color-accent-gold-hover: #b89320;
  --color-midnight: #2e3642;

  /* Typography — Fonts */
  --font-sf-pro-display: 'Outfit', 'SF Pro Display', ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-sf-pro-text: 'Inter', 'SF Pro Text', ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

  /* Typography — Scale */
  --text-micro: 12px;
  --text-caption: 14px;
  --text-body-sm: 17px;
  --text-body: 21px;
  --text-body-lg: 28px;
  --text-subheading: 32px;
  --text-heading-sm: 40px;
  --text-heading: 56px;
  --text-heading-lg: 80px;
  --text-display: 96px;

  /* Spacing */
  --spacing-4: 4px;
  --spacing-8: 8px;
  --spacing-12: 12px;
  --spacing-16: 16px;
  --spacing-20: 20px;
  --spacing-24: 24px;
  --spacing-28: 28px;
  --spacing-32: 32px;
  --spacing-40: 40px;
  --spacing-48: 48px;
  --spacing-80: 80px;
  --spacing-120: 120px;

  /* Geometry & Border Radius */
  --radius-lg: 10px;
  --radius-cards: 28px;
  --radius-badges: 36px;
  --radius-buttons: 980px;
  --radius-full: 9999px;

  /* Elevation Shadows */
  --shadow-sm: 0 2px 10px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 12px 32px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 24px 48px rgba(0, 0, 0, 0.12);
  --shadow-gold: 0 10px 25px rgba(212, 175, 55, 0.3);
  --shadow-blue: 0 10px 25px rgba(0, 113, 227, 0.3);

  /* Apple Spring Animations */
  --ease-apple: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.25, 1, 0.5, 1);
  --transition-fast: all 0.25s var(--ease-apple);
  --transition-smooth: all 0.5s var(--ease-apple);
}

/* 2. BASE & RESET */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-sf-pro-text);
  background-color: var(--color-canvas);
  color: var(--color-primary-ink);
  line-height: 1.6;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-sf-pro-display);
  color: var(--color-primary-ink);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.025em;
}

a {
  text-decoration: none;
  color: inherit;
  transition: var(--transition-fast);
}

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

.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* 3. HEADER & NAVIGATION */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(15, 45, 34, 0.94);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  padding: 0.85rem 0;
  transition: var(--transition-smooth);
}

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

.logo-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--color-paper);
  margin-right: 2.5rem;
  flex-shrink: 0;
}

.logo-text {
  font-size: 1.18rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  white-space: nowrap;
}

.logo-text span {
  color: var(--color-accent-gold);
}

.main-nav {
  display: flex;
  align-items: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 1.35rem;
  list-style: none;
}

.nav-link {
  color: rgba(255, 255, 255, 0.88);
  font-size: 0.92rem;
  font-weight: 500;
  padding: 0.4rem 0;
  position: relative;
  white-space: nowrap;
}

.nav-link:hover, .nav-link.active {
  color: var(--color-accent-gold);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--color-accent-gold);
  transition: var(--transition-smooth);
  border-radius: 2px;
}

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

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-paper);
  font-size: 1.8rem;
  cursor: pointer;
}

/* 4. HERO CAROUSEL */
.hero-section {
  position: relative;
  height: 92vh;
  min-height: 620px;
  background: var(--color-primary-ink);
  overflow: hidden;
}

.carousel-slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  visibility: hidden;
  transition: opacity 1.2s var(--ease-apple), transform 1.4s var(--ease-apple);
  transform: scale(1.05);
}

.carousel-slide.active {
  opacity: 1;
  visibility: visible;
  transform: scale(1);
}

.slide-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  transition: transform 10s ease-out;
}

.carousel-slide.active .slide-bg {
  transform: scale(1.04);
}

.slide-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(29, 29, 31, 0.75) 0%, rgba(15, 45, 34, 0.88) 100%);
}

.hero-content {
  position: relative;
  z-index: 10;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  max-width: 820px;
  color: var(--color-paper);
  padding-top: 4rem;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1.1rem;
  background: rgba(212, 175, 55, 0.22);
  border: 1px solid rgba(212, 175, 55, 0.5);
  color: var(--color-accent-gold);
  border-radius: var(--radius-badges);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 1.5rem;
  width: fit-content;
  backdrop-filter: blur(8px);
}

.hero-title {
  font-size: clamp(2.6rem, 5.2vw, 4.4rem);
  font-weight: 800;
  color: var(--color-paper);
  margin-bottom: 1.25rem;
  letter-spacing: -0.035em;
  text-shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
}

.hero-desc {
  font-size: 1.18rem;
  color: rgba(255, 255, 255, 0.92);
  margin-bottom: 2.25rem;
  max-width: 660px;
}

.hero-btns {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.9rem 2.2rem;
  font-family: var(--font-sf-pro-display);
  font-weight: 600;
  font-size: 1rem;
  border-radius: var(--radius-buttons);
  cursor: pointer;
  border: none;
  transition: var(--transition-smooth);
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-accent-gold), #b89320);
  color: var(--color-midnight);
  box-shadow: var(--shadow-gold);
}

.btn-primary:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 16px 32px rgba(212, 175, 55, 0.45);
  background: linear-gradient(135deg, #e5be48, var(--color-accent-gold));
}

.btn-electric {
  background: var(--color-electric-blue);
  color: var(--color-paper);
  box-shadow: var(--shadow-blue);
}

.btn-electric:hover {
  transform: translateY(-3px) scale(1.02);
  background: #0077ed;
  box-shadow: 0 16px 32px rgba(0, 113, 227, 0.45);
}

.btn-outline {
  background: rgba(255, 255, 255, 0.12);
  color: var(--color-paper);
  border: 1px solid rgba(255, 255, 255, 0.35);
  backdrop-filter: blur(12px);
}

.btn-outline:hover {
  background: var(--color-paper);
  color: var(--color-primary-ink);
  transform: translateY(-3px);
}

.carousel-nav-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 20;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: var(--color-paper);
  font-size: 1.5rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(12px);
  transition: var(--transition-smooth);
}

.carousel-nav-btn:hover {
  background: var(--color-accent-gold);
  color: var(--color-midnight);
  transform: translateY(-50%) scale(1.1);
}

.carousel-prev { left: 2rem; }
.carousel-next { right: 2rem; }

/* 5. SECTIONS & SCROLL ANIMATIONS */
.section {
  padding: 6.5rem 0;
}

.section-header {
  text-align: center;
  max-width: 750px;
  margin: 0 auto 4rem auto;
}

.sub-title {
  color: var(--color-accent-gold);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.85rem;
  margin-bottom: 0.5rem;
  display: block;
}

.section-title {
  font-size: clamp(2rem, 3.5vw, 2.75rem);
  color: var(--color-primary-ink);
  letter-spacing: -0.025em;
  margin-bottom: 1rem;
}

.section-desc {
  color: var(--color-mid-gray);
  font-size: 1.08rem;
}

/* Scroll Animation Classes */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px) scale(0.98);
  transition: opacity 0.8s var(--ease-apple), transform 0.8s var(--ease-apple);
}

.animate-on-scroll.animated {
  opacity: 1;
  transform: translateY(0) scale(1);
}

/* 6. ABOUT / STORY SECTION */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4.5rem;
  align-items: center;
}

.about-image-wrapper {
  position: relative;
}

.about-img-main {
  border-radius: var(--radius-cards);
  box-shadow: var(--shadow-lg);
  width: 100%;
  height: 480px;
  object-fit: cover;
  transition: transform 0.6s var(--ease-apple);
}

.about-img-main:hover {
  transform: scale(1.02);
}

.about-experience-badge {
  position: absolute;
  bottom: -24px;
  right: -24px;
  background: var(--color-primary-ink);
  color: var(--color-paper);
  padding: 1.6rem 2.2rem;
  border-radius: var(--radius-cards);
  box-shadow: var(--shadow-lg);
  border: 2px solid var(--color-accent-gold);
  text-align: center;
}

.experience-number {
  font-size: 2.8rem;
  font-weight: 800;
  color: var(--color-accent-gold);
  font-family: var(--font-sf-pro-display);
  line-height: 1;
}

.experience-text {
  font-size: 0.85rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.about-text-content h3 {
  font-size: 2.2rem;
  margin-bottom: 1.25rem;
  color: var(--color-primary-ink);
}

.about-text-content p {
  color: var(--color-deep-gray);
  margin-bottom: 1.25rem;
  font-size: 1.05rem;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 2.2rem;
  padding-top: 2.2rem;
  border-top: 1px solid var(--color-hairline);
}

.stat-item h4 {
  font-size: 1.9rem;
  color: var(--color-electric-blue);
}

.stat-item p {
  font-size: 0.88rem;
  color: var(--color-mid-gray);
  margin-bottom: 0;
}

/* 7. SECTOR CARDS & CARDS GRID */
.sectors-grid, .cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

.sector-card, .feature-card {
  background: var(--color-paper);
  border-radius: var(--radius-cards);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition-smooth);
  border: 1px solid rgba(0,0,0,0.06);
  display: flex;
  flex-direction: column;
}

.sector-card:hover, .feature-card:hover {
  transform: translateY(-8px) scale(1.015);
  box-shadow: var(--shadow-lg);
  border-color: rgba(212, 175, 55, 0.4);
}

.sector-img-box {
  position: relative;
  height: 230px;
  overflow: hidden;
  border-radius: var(--radius-cards) var(--radius-cards) 0 0;
}

.sector-img-box img, .feature-card-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.7s var(--ease-apple);
}

.sector-card:hover .sector-img-box img, .feature-card:hover .feature-card-img {
  transform: scale(1.08);
}

.sector-icon {
  position: absolute;
  bottom: 1rem;
  right: 1rem;
  width: 50px;
  height: 50px;
  background: var(--color-primary-ink);
  color: var(--color-accent-gold);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  box-shadow: var(--shadow-md);
}

.sector-body, .feature-card-body {
  padding: 1.85rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.sector-title, .feature-card-title {
  font-size: 1.35rem;
  margin-bottom: 0.75rem;
  color: var(--color-primary-ink);
}

.sector-desc, .feature-notes {
  color: var(--color-mid-gray);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.feature-tag {
  display: inline-block;
  padding: 0.3rem 0.85rem;
  background: var(--color-cool-wash);
  color: var(--color-electric-blue);
  font-size: 0.82rem;
  font-weight: 600;
  border-radius: var(--radius-badges);
  margin-bottom: 0.85rem;
  width: fit-content;
}

.sector-link {
  color: var(--color-electric-blue);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.95rem;
}

.sector-link:hover {
  color: var(--color-link-blue);
  gap: 0.75rem;
}

/* 8. CONTACT SECTION */
.contact-section {
  background: linear-gradient(135deg, var(--color-primary-ink) 0%, #0a1f18 100%);
  color: var(--color-paper);
}

/* 9. GALLERY FILTER */
.gallery-filters {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 0.65rem 1.6rem;
  border: 1px solid var(--color-hairline);
  background: var(--color-paper);
  color: var(--color-primary-ink);
  border-radius: var(--radius-buttons);
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  transition: var(--transition-fast);
}

.filter-btn.active, .filter-btn:hover {
  background: var(--color-primary-ink);
  color: var(--color-accent-gold);
  border-color: var(--color-primary-ink);
  transform: translateY(-2px);
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.gallery-item {
  position: relative;
  border-radius: var(--radius-cards);
  overflow: hidden;
  height: 270px;
  cursor: pointer;
  transition: transform 0.5s var(--ease-apple);
}

.gallery-item:hover {
  transform: translateY(-4px) scale(1.02);
}

.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s var(--ease-apple);
}

.gallery-item:hover img {
  transform: scale(1.1);
}

.gallery-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 40%, rgba(29, 29, 31, 0.92) 100%);
  display: flex;
  align-items: flex-end;
  padding: 1.5rem;
  color: var(--color-paper);
  opacity: 0;
  transition: opacity 0.35s ease;
}

.gallery-item:hover .gallery-overlay {
  opacity: 1;
}

/* 10. FOOTER */
.site-footer {
  background: var(--color-primary-ink);
  color: rgba(255, 255, 255, 0.85);
  padding: 5.5rem 0 2.5rem 0;
  border-top: 4px solid var(--color-accent-gold);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 3rem;
  margin-bottom: 4rem;
}

.footer-brand h3 {
  color: var(--color-paper);
  font-size: 1.5rem;
  margin-bottom: 1rem;
}

.footer-brand p {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
}

.footer-col h4 {
  color: var(--color-accent-gold);
  font-size: 1.1rem;
  margin-bottom: 1.25rem;
}

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

.footer-links li {
  margin-bottom: 0.75rem;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.75);
  font-size: 0.92rem;
}

.footer-links a:hover {
  color: var(--color-accent-gold);
  padding-left: 0.5rem;
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  font-size: 0.88rem;
  color: rgba(255, 255, 255, 0.6);
}

/* 11. RESPONSIVE BREAKPOINTS */
@media (max-width: 1100px) {
  .logo-brand {
    margin-right: 1rem;
  }
  
  .nav-list {
    gap: 1rem;
  }
  
  .nav-link {
    font-size: 0.88rem;
  }
}

@media (max-width: 992px) {
  .about-grid {
    grid-template-columns: 1fr;
  }

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

  .mobile-toggle {
    display: block;
  }

  .main-nav {
    position: fixed;
    top: 70px;
    right: -100%;
    width: 280px;
    height: calc(100vh - 70px);
    background: var(--color-primary-ink);
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    transition: right 0.35s ease;
  }

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

  .nav-list {
    flex-direction: column;
    align-items: flex-start;
    gap: 1.25rem;
  }
}

@media (max-width: 600px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }

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

  .carousel-prev, .carousel-next {
    display: none;
  }
}