/* ==========================================================================
   BASKARA RIAU TEKNIK (BRT) - STANDARDIZED DESIGN SYSTEM
   Medium Voltage 20 kV & Low Voltage Industrial Electrical Contractor
   Standardized UI/UX Architecture for Scalability & Future Upgrades
   ========================================================================== */

/* ==========================================================================
   1. DESIGN TOKENS (CSS Custom Properties)
   ========================================================================== */
:root {
  /* --- 1.1 Brand Color Primitives --- */
  --brt-navy: #12223B;          /* Primary Brand Navy */
  --brt-navy-dark: #0E1A2E;     /* Deep Navy Background / Dark Mode Base */
  --brt-navy-2: #1C3152;        /* Surface Navy / Card Background */
  --brt-navy-surface: #172B4A;  /* Elevated Navy Surface */
  --brt-navy-border: #284268;   /* Industrial Border Navy */
  
  --brt-yellow: #F2B10A;        /* Electric Gold / Accent */
  --brt-yellow-hover: #F7BC22;  /* Interactive Hover Gold */
  --brt-yellow-glow: rgba(242, 177, 10, 0.25);
  --brt-yellow-subtle: rgba(242, 177, 10, 0.12);
  --brt-gold-gradient: linear-gradient(135deg, #FFE27A 0%, #F2B10A 50%, #C88E00 100%);
  --brt-gold-gradient-hover: linear-gradient(135deg, #FFF0A8 0%, #F7C32A 50%, #DE9F00 100%);
  --brt-gold-text-gradient: linear-gradient(135deg, #FFF0A8 0%, #F2B10A 55%, #D49800 100%);
  --brt-navy-obsidian: #0A1424;
  --brt-border-gold-subtle: rgba(242, 177, 10, 0.18);
  --brt-border-gold-hover: rgba(242, 177, 10, 0.5);
  --brt-shadow-luxury: 0 20px 45px -15px rgba(0, 0, 0, 0.6), 0 0 30px -5px rgba(242, 177, 10, 0.25);

  --brt-cream: #F6F4EE;         /* Warm Cream Box / Light Mode Base */
  --brt-cream-2: #ECE8DE;       /* Warm Gray Cream Surface */
  --brt-border-cream: #DDD7CA;  /* Cream Border */
  --brt-white: #FFFFFF;

  --brt-red: #B3202A;           /* Industrial Warning Red */
  --brt-green: #1F9D55;         /* Success / Safety Green */
  --brt-whatsapp: #25D366;      /* Official WhatsApp Green */

  /* --- 1.2 WCAG 2.1 AA Contrast Text Tokens --- */
  --brt-text-dark: #12223B;     /* Primary text on light background (contrast 12.8:1) */
  --brt-text-body: #46505E;     /* Body text on light background (contrast 5.6:1) */
  --brt-text-muted: #5A626E;    /* Secondary text on light background (contrast 4.6:1) */

  --brt-text-light: #F6F4EE;    /* Primary text on dark background (contrast 13.5:1) */
  --brt-text-on-dark: #C9D3E0;  /* Body text on dark background (contrast 9.2:1) */
  --brt-muted-on-dark: #9FB0C6; /* Secondary text on dark background (contrast 6.1:1) */

  /* --- 1.3 Typography Stacks --- */
  --brt-font-heading: 'Oswald', 'PingFang SC', 'Microsoft YaHei', 'Arial Narrow', sans-serif;
  --brt-font-body: 'Public Sans', 'PingFang SC', 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --brt-font-mono: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;

  /* --- 1.4 Fluid Typography Scale --- */
  --brt-text-display: clamp(2.25rem, 5vw + 1rem, 3.75rem);   /* 36px - 60px */
  --brt-text-h1: clamp(1.85rem, 3.5vw + 0.5rem, 2.75rem);    /* 30px - 44px */
  --brt-text-h2: clamp(1.5rem, 2.5vw + 0.5rem, 2.25rem);     /* 24px - 36px */
  --brt-text-h3: clamp(1.25rem, 1.8vw + 0.25rem, 1.65rem);   /* 20px - 26px */
  --brt-text-h4: clamp(1.1rem, 1.2vw + 0.1rem, 1.3rem);      /* 17px - 21px */
  --brt-text-lead: clamp(1.05rem, 1vw + 0.2rem, 1.25rem);     /* 17px - 20px */
  --brt-text-base: 1rem;                                     /* 16px */
  --brt-text-sm: 0.875rem;                                   /* 14px */
  --brt-text-xs: 0.75rem;                                    /* 12px */

  /* --- 1.5 Spacing Scale (4px Modular Grid) --- */
  --brt-space-1: 4px;
  --brt-space-2: 8px;
  --brt-space-3: 12px;
  --brt-space-4: 16px;
  --brt-space-5: 20px;
  --brt-space-6: 24px;
  --brt-space-8: 32px;
  --brt-space-10: 40px;
  --brt-space-12: 48px;
  --brt-space-16: 64px;
  --brt-space-20: 80px;
  --brt-space-24: 96px;

  /* --- 1.6 Layout Dimensions --- */
  --brt-container-max: 1440px;
  --brt-container-narrow: 960px;
  --brt-header-height: 72px;
  --brt-header-height-mobile: 58px;

  /* --- 1.7 Border Radii --- */
  --brt-radius-xs: 4px;
  --brt-radius-sm: 6px;
  --brt-radius-md: 8px;
  --brt-radius-lg: 12px;
  --brt-radius-card: 16px;
  --brt-radius-pill: 9999px;

  /* --- 1.8 Shadows / Elevation --- */
  --brt-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.08);
  --brt-shadow-md: 0 4px 14px rgba(0, 0, 0, 0.18), 0 2px 6px rgba(0, 0, 0, 0.12);
  --brt-shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.28), 0 4px 12px rgba(0, 0, 0, 0.16);
  --brt-shadow-glow: 0 0 20px rgba(242, 177, 10, 0.35);

  /* --- 1.9 Transitions & Durations --- */
  --brt-transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --brt-transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --brt-transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);

  /* --- 1.10 Z-Index Scale --- */
  --brt-z-base: 1;
  --brt-z-dropdown: 50;
  --brt-z-sticky: 100;
  --brt-z-floating: 150;
  --brt-z-backdrop: 200;
  --brt-z-drawer: 250;
  --brt-z-modal: 300;
  --brt-z-toast: 400;
  --brt-z-skip-link: 9999;

  /* --- 1.11 Default Semantic Theme (Dark Industrial) --- */
  --theme-bg-main: var(--brt-navy);
  --theme-bg-alt: var(--brt-navy-dark);
  --theme-bg-card: var(--brt-navy-2);
  --theme-border: var(--brt-navy-border);
  --theme-border-card: var(--brt-navy-border);
  --theme-text-title: var(--brt-cream);
  --theme-text-body: var(--brt-text-on-dark);
  --theme-text-muted: var(--brt-muted-on-dark);
  --theme-header-bg: rgba(18, 34, 59, 0.95);
  --theme-drawer-bg: var(--brt-navy-dark);
  --theme-drawer-text: var(--brt-cream);
  --theme-drawer-link: var(--brt-cream);
  --theme-drawer-border: var(--brt-navy-border);

  /* Backward Compatibility Aliases for hero.css and subpages.css */
  --navy: var(--brt-navy);
  --navy-2: var(--brt-navy-2);
  --navy-dark: var(--brt-navy-dark);
  --cream: var(--brt-cream);
  --cream-2: var(--brt-cream-2);
  --white: var(--brt-white);
  --yellow: var(--brt-yellow);
  --yellow-hover: var(--brt-yellow-hover);
  --red: var(--brt-red);
  --border-cream: var(--brt-border-cream);
  --font-heading: var(--brt-font-heading);
  --font-body: var(--brt-font-body);
  --container-max: var(--brt-container-max);
  --radius-card: var(--brt-radius-card);
  --radius-btn: var(--brt-radius-md);
  --radius-pill: var(--brt-radius-pill);
}

/* --- 1.12 Light Theme Override (WCAG 2.1 AA Compliant) --- */
html[data-theme="light"] {
  --theme-bg-main: var(--brt-cream);
  --theme-bg-alt: var(--brt-cream-2);
  --theme-bg-card: var(--brt-white);
  --theme-border: var(--brt-border-cream);
  --theme-border-card: var(--brt-border-cream);
  --theme-text-title: var(--brt-navy);
  --theme-text-body: var(--brt-text-body);
  --theme-text-muted: var(--brt-text-muted);
  --theme-header-bg: rgba(246, 244, 238, 0.96);
  --theme-drawer-bg: var(--brt-cream);
  --theme-drawer-text: var(--brt-navy);
  --theme-drawer-link: var(--brt-navy);
  --theme-drawer-border: var(--brt-border-cream);
}

/* --- 1.13 Dark Theme Explicit Override (WCAG AAA Compliant) --- */
html[data-theme="dark"] {
  --theme-bg-main: var(--brt-navy-dark);
  --theme-bg-alt: var(--brt-navy);
  --theme-bg-card: var(--brt-navy-2);
  --theme-border: var(--brt-navy-border);
  --theme-border-card: var(--brt-navy-border);
  --theme-text-title: var(--brt-cream);
  --theme-text-body: var(--brt-text-on-dark);
  --theme-text-muted: var(--brt-muted-on-dark);
  --theme-header-bg: rgba(14, 26, 46, 0.96);
  --theme-drawer-bg: var(--brt-navy-dark);
  --theme-drawer-text: var(--brt-cream);
  --theme-drawer-link: var(--brt-cream);
  --theme-drawer-border: var(--brt-navy-border);
}

/* ==========================================================================
   2. ACCESSIBILITY & BASE RESETS (WCAG 2.1 AA Compliant)
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
}

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

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

body.brt-body {
  margin: 0;
  padding: 0;
  background-color: var(--theme-bg-main);
  color: var(--theme-text-body);
  font-family: var(--brt-font-body);
  font-size: var(--brt-text-base);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: background-color var(--brt-transition-base), color var(--brt-transition-base);
}

/* Skip to Content Link (WCAG 2.4.1) */
.brt-skip-link {
  position: absolute;
  top: -120px;
  left: 20px;
  background-color: var(--brt-yellow);
  color: var(--brt-navy);
  font-family: var(--brt-font-heading);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 12px 24px;
  border-radius: var(--brt-radius-md);
  text-decoration: none;
  z-index: var(--brt-z-skip-link);
  box-shadow: var(--brt-shadow-lg);
  transition: top var(--brt-transition-fast) ease-in-out;
}

.brt-skip-link:focus {
  top: 16px;
  outline: 3px solid var(--brt-cream);
  outline-offset: 3px;
}

/* Standardized Keyboard Focus Ring (WCAG 2.4.7) */
:focus-visible {
  outline: 3px solid var(--brt-yellow) !important;
  outline-offset: 3px !important;
}

html[data-theme="light"] :focus-visible {
  outline: 3px solid var(--brt-navy) !important;
  outline-offset: 3px !important;
}

/* ==========================================================================
   3. STANDARDIZED LAYOUT SYSTEM
   ========================================================================== */
.brt-container {
  width: 100%;
  max-width: var(--brt-container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--brt-space-10);
  padding-right: var(--brt-space-10);
}

.brt-container--narrow {
  max-width: var(--brt-container-narrow);
}

.brt-container--fluid {
  max-width: 100%;
}

@media (max-width: 1080px) {
  .brt-container {
    padding-left: var(--brt-space-6);
    padding-right: var(--brt-space-6);
  }
}

@media (max-width: 767px) {
  .brt-container {
    padding-left: var(--brt-space-4);
    padding-right: var(--brt-space-4);
  }
}

/* Section Wrappers with Standardized Spacing */
.brt-section {
  padding-top: var(--brt-space-20);
  padding-bottom: var(--brt-space-20);
  position: relative;
}

.brt-section--sm {
  padding-top: var(--brt-space-12);
  padding-bottom: var(--brt-space-12);
}

.brt-section--navy {
  background-color: var(--brt-navy);
  color: var(--brt-text-on-dark);
}

.brt-section--navy-dark {
  background-color: var(--brt-navy-dark);
  color: var(--brt-text-on-dark);
}

.brt-section--cream {
  background-color: var(--brt-cream);
  color: var(--brt-text-body);
}

@media (max-width: 767px) {
  .brt-section {
    padding-top: var(--brt-space-12);
    padding-bottom: var(--brt-space-12);
  }
}

/* Grid System */
.brt-grid {
  display: grid;
  gap: var(--brt-space-6);
}

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

.brt-grid--3col {
  grid-template-columns: repeat(3, 1fr);
}

.brt-grid--4col {
  grid-template-columns: repeat(4, 1fr);
}

@media (max-width: 1080px) {
  .brt-grid--4col {
    grid-template-columns: repeat(2, 1fr);
  }
  .brt-grid--3col {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 767px) {
  .brt-grid--4col,
  .brt-grid--3col,
  .brt-grid--2col {
    grid-template-columns: 1fr;
  }
}

/* Flex Utilities */
.brt-flex {
  display: flex;
}

.brt-flex--align-center {
  align-items: center;
}

.brt-flex--between {
  justify-content: space-between;
}

.brt-flex--center {
  align-items: center;
  justify-content: center;
}

.brt-flex--wrap {
  flex-wrap: wrap;
}

.brt-gap-sm { gap: var(--brt-space-2); }
.brt-gap-md { gap: var(--brt-space-4); }
.brt-gap-lg { gap: var(--brt-space-6); }

/* ==========================================================================
   4. STANDARDIZED COMPONENT LIBRARY
   ========================================================================== */

/* --- 4.1 Button System (.brt-btn) --- */
.brt-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-family: var(--brt-font-heading);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-decoration: none;
  min-height: 44px;
  padding: 10px 22px;
  border-radius: var(--brt-radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--brt-transition-base);
  user-select: none;
  white-space: nowrap;
}

.brt-btn--primary {
  background: var(--brt-gold-gradient, linear-gradient(135deg, #FFE27A 0%, #F2B10A 50%, #C88E00 100%));
  color: var(--brt-navy);
  border: 1px solid rgba(255, 255, 255, 0.25);
  box-shadow: 0 4px 16px rgba(242, 177, 10, 0.35), inset 0 1px 0 rgba(255, 255, 255, 0.4);
  font-weight: 700;
  letter-spacing: 0.04em;
  transition: all var(--brt-transition-base);
}

.brt-btn--primary:hover {
  background: var(--brt-gold-gradient-hover, linear-gradient(135deg, #FFF0A8 0%, #F7C32A 50%, #DE9F00 100%));
  border-color: rgba(255, 255, 255, 0.4);
  color: var(--brt-navy);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(242, 177, 10, 0.48), 0 0 16px rgba(242, 177, 10, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.6);
}

.brt-btn--primary:active {
  transform: translateY(0);
  box-shadow: 0 2px 6px rgba(242, 177, 10, 0.25);
}

.brt-btn--secondary {
  background-color: transparent;
  color: var(--brt-cream);
  border: 1.5px solid var(--brt-cream);
}

.brt-btn--secondary:hover {
  background-color: var(--brt-cream);
  color: var(--brt-navy);
  transform: translateY(-2px);
  box-shadow: var(--brt-shadow-md);
}

html[data-theme="light"] .brt-btn--secondary {
  color: var(--brt-navy);
  border-color: var(--brt-navy);
}

html[data-theme="light"] .brt-btn--secondary:hover {
  background-color: var(--brt-navy);
  color: var(--brt-cream);
}

.brt-btn--whatsapp {
  background-color: var(--brt-whatsapp);
  color: #FFFFFF;
  border-color: var(--brt-whatsapp);
  box-shadow: 0 2px 8px rgba(37, 211, 102, 0.25);
}

.brt-btn--whatsapp:hover {
  background-color: #20BA5A;
  color: #FFFFFF;
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(37, 211, 102, 0.4);
}

.brt-btn--outline-gold {
  background-color: transparent;
  color: var(--brt-yellow);
  border: 1.5px solid var(--brt-yellow);
}

.brt-btn--outline-gold:hover {
  background-color: var(--brt-yellow);
  color: var(--brt-navy);
  transform: translateY(-2px);
}

.brt-btn--sm {
  min-height: 38px;
  padding: 6px 14px;
  font-size: 13px;
}

.brt-btn--lg {
  min-height: 52px;
  padding: 14px 32px;
  font-size: 17px;
}

.brt-btn--block {
  width: 100%;
}

.brt-btn:disabled,
.brt-btn.is-disabled {
  opacity: 0.55;
  cursor: not-allowed;
  pointer-events: none;
  transform: none !important;
  box-shadow: none !important;
}

/* --- 4.2 Card System (.brt-card) --- */
.brt-card {
  background-color: var(--theme-bg-card);
  border: 1px solid var(--theme-border-card);
  border-radius: var(--brt-radius-card);
  padding: var(--brt-space-6);
  position: relative;
  overflow: hidden;
  transition: transform var(--brt-transition-base), box-shadow var(--brt-transition-base), border-color var(--brt-transition-base);
}

.brt-card--interactive:hover {
  transform: translateY(-4px);
  box-shadow: var(--brt-shadow-lg);
  border-color: var(--brt-yellow);
}

.brt-card__media {
  border-radius: var(--brt-radius-md);
  overflow: hidden;
  margin-bottom: var(--brt-space-4);
  aspect-ratio: 16 / 9;
  background-color: var(--brt-navy-dark);
}

.brt-card__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--brt-transition-slow);
}

.brt-card--interactive:hover .brt-card__media img {
  transform: scale(1.04);
}

.brt-card__title {
  font-family: var(--brt-font-heading);
  font-weight: 700;
  font-size: var(--brt-text-h3);
  text-transform: uppercase;
  color: var(--theme-text-title);
  margin: 0 0 var(--brt-space-2) 0;
  letter-spacing: 0.02em;
}

.brt-card__body {
  font-size: var(--brt-text-sm);
  color: var(--theme-text-body);
  line-height: 1.6;
}

/* --- 4.3 Badges & Pills (.brt-badge) --- */
.brt-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: var(--brt-radius-pill);
  font-family: var(--brt-font-heading);
  font-weight: 700;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  white-space: nowrap;
}

.brt-badge--yellow {
  background-color: var(--brt-yellow-subtle);
  color: var(--brt-yellow);
  border: 1px solid rgba(242, 177, 10, 0.35);
}

.brt-badge--navy {
  background-color: rgba(18, 34, 59, 0.85);
  color: var(--brt-cream);
  border: 1px solid rgba(246, 244, 238, 0.2);
}

.brt-badge--green {
  background-color: rgba(31, 157, 85, 0.15);
  color: var(--brt-green);
  border: 1px solid rgba(31, 157, 85, 0.35);
}

.brt-badge--red {
  background-color: rgba(179, 32, 42, 0.15);
  color: var(--brt-red);
  border: 1px solid rgba(179, 32, 42, 0.35);
}

/* --- 4.4 Form Control System --- */
.brt-form-group {
  margin-bottom: var(--brt-space-5);
  text-align: left;
}

.brt-label {
  display: block;
  font-family: var(--brt-font-heading);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--theme-text-title);
  margin-bottom: var(--brt-space-2);
}

.brt-label--required::after {
  content: ' *';
  color: var(--brt-yellow);
}

.brt-input,
.brt-select,
.brt-textarea {
  width: 100%;
  min-height: 48px;
  padding: 10px 16px;
  border-radius: var(--brt-radius-md);
  border: 1px solid var(--theme-border);
  background-color: var(--theme-bg-alt);
  color: var(--theme-text-title);
  font-family: var(--brt-font-body);
  font-size: 15px;
  transition: border-color var(--brt-transition-fast), box-shadow var(--brt-transition-fast);
}

.brt-input::placeholder,
.brt-textarea::placeholder {
  color: var(--theme-text-muted);
  opacity: 0.8;
}

.brt-input:hover,
.brt-select:hover,
.brt-textarea:hover {
  border-color: rgba(242, 177, 10, 0.5);
}

.brt-input:focus,
.brt-select:focus,
.brt-textarea:focus {
  outline: none;
  border-color: var(--brt-yellow);
  box-shadow: 0 0 0 3px var(--brt-yellow-glow);
}

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

.brt-form-hint {
  font-size: 12px;
  color: var(--theme-text-muted);
  margin-top: var(--brt-space-1);
}

.brt-form-feedback {
  font-size: 13px;
  margin-top: var(--brt-space-1);
  display: flex;
  align-items: center;
  gap: 6px;
}

.brt-form-feedback--error { color: var(--brt-red); }
.brt-form-feedback--success { color: var(--brt-green); }

/* --- 4.5 Standardized Tables (.brt-table) --- */
.brt-table-responsive {
  width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-radius: var(--brt-radius-md);
  border: 1px solid var(--theme-border);
  margin-bottom: var(--brt-space-6);
}

.brt-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: var(--brt-text-sm);
}

.brt-table th {
  background-color: var(--brt-navy-dark);
  color: var(--brt-cream);
  font-family: var(--brt-font-heading);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 14px 18px;
  border-bottom: 2px solid var(--brt-yellow);
}

html[data-theme="light"] .brt-table th {
  background-color: var(--brt-cream-2);
  color: var(--brt-navy);
}

.brt-table td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--theme-border);
  color: var(--theme-text-body);
}

.brt-table tr:hover td {
  background-color: var(--brt-yellow-subtle);
}

/* --- 4.6 Breadcrumbs (.brt-breadcrumb) --- */
.brt-breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 13px;
  color: var(--brt-muted-on-dark);
  margin-bottom: var(--brt-space-6);
}

.brt-breadcrumb ol {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.brt-breadcrumb li {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.brt-breadcrumb a {
  color: var(--brt-text-on-dark);
  text-decoration: none;
  transition: color var(--brt-transition-fast);
}

.brt-breadcrumb a:hover {
  color: var(--brt-yellow);
}

.brt-breadcrumb__sep {
  opacity: 0.4;
  user-select: none;
}

.brt-breadcrumb__current {
  color: var(--brt-yellow);
  font-weight: 600;
}

/* --- 4.7 Alerts & Callouts (.brt-alert) --- */
.brt-alert {
  padding: var(--brt-space-4) var(--brt-space-5);
  border-radius: var(--brt-radius-md);
  border-left: 4px solid var(--brt-yellow);
  background-color: var(--theme-bg-card);
  margin-bottom: var(--brt-space-6);
  display: flex;
  align-items: flex-start;
  gap: 14px;
  font-size: 14px;
}

.brt-alert--info {
  border-left-color: var(--brt-yellow);
  background-color: rgba(242, 177, 10, 0.08);
}

.brt-alert--success {
  border-left-color: var(--brt-green);
  background-color: rgba(31, 157, 85, 0.08);
}

.brt-alert--warning {
  border-left-color: var(--brt-red);
  background-color: rgba(179, 32, 42, 0.08);
}

/* --- 4.8 Back to Top Button (.brt-back-to-top) --- */
.brt-back-to-top {
  position: fixed;
  bottom: 88px;
  right: 24px;
  z-index: var(--brt-z-floating);
  width: 46px;
  height: 46px;
  min-width: 44px;
  min-height: 44px;
  border-radius: 50%;
  background-color: var(--brt-navy);
  color: var(--brt-yellow);
  border: 1.5px solid var(--brt-yellow);
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: all var(--brt-transition-base);
}

.brt-back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.brt-back-to-top:hover {
  background-color: var(--brt-yellow);
  color: var(--brt-navy);
  transform: translateY(-3px);
  box-shadow: 0 6px 18px rgba(242, 177, 10, 0.4);
}

@media (max-width: 767px) {
  .brt-back-to-top {
    bottom: 74px;
    right: 18px;
    width: 44px;
    height: 44px;
  }
}

/* --- 4.9 Scrolled Header Enhancement --- */
.brt-header.is-scrolled {
  background: var(--theme-header-bg);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.45);
  border-bottom: 1px solid rgba(242, 177, 10, 0.25);
}

/* ==========================================================================
   4.10 LUXURY & HIGH-END INDUSTRIAL ENGINEERING UTILITIES ("Mewah & Gahar")
   ========================================================================== */

/* Metallic Gold & Silver Text Gradients */
.brt-text-gold-gradient {
  background: var(--brt-gold-text-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.brt-text-silver-gradient {
  background: linear-gradient(135deg, #FFFFFF 0%, #D8E0EB 50%, #9EB0C8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

/* Luxury Obsidian Card with Subtle Top Gold Hairline & Dynamic Hover Glow */
.brt-card-luxury {
  background: linear-gradient(145deg, rgba(28, 49, 82, 0.85) 0%, rgba(14, 26, 46, 0.95) 100%);
  border: 1px solid var(--brt-border-gold-subtle);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-radius: var(--brt-radius-card);
  padding: 32px 28px;
  position: relative;
  overflow: hidden;
  transition: transform var(--brt-transition-slow), border-color var(--brt-transition-base), box-shadow var(--brt-transition-slow);
}

.brt-card-luxury::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(242, 177, 10, 0.6), transparent);
  opacity: 0.6;
  transition: opacity var(--brt-transition-base);
}

.brt-card-luxury:hover {
  transform: translateY(-6px);
  border-color: var(--brt-border-gold-hover);
  box-shadow: var(--brt-shadow-luxury);
}

.brt-card-luxury:hover::before {
  opacity: 1;
}

[data-theme="light"] .brt-card-luxury {
  background: #FFFFFF;
  border-color: rgba(221, 215, 202, 0.8);
  box-shadow: 0 4px 20px rgba(18, 34, 59, 0.06);
}

[data-theme="light"] .brt-card-luxury:hover {
  border-color: var(--brt-yellow);
  box-shadow: 0 12px 30px rgba(18, 34, 59, 0.12), 0 0 20px rgba(242, 177, 10, 0.15);
}

/* Luxury Divider (Laser-cut Subtle Gold Glow Line) */
.brt-luxury-divider {
  height: 1px;
  width: 100%;
  max-width: var(--brt-container-max);
  margin: 48px auto;
  background: linear-gradient(90deg, transparent 0%, rgba(242, 177, 10, 0.35) 50%, transparent 100%);
  border: none;
}

/* Luxury Industrial Pill Badges */
.brt-badge--luxury {
  background: rgba(242, 177, 10, 0.1);
  border: 1px solid rgba(242, 177, 10, 0.35);
  color: var(--brt-yellow);
  font-family: var(--brt-font-heading);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 5px 14px;
  border-radius: var(--brt-radius-pill);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  box-shadow: inset 0 0 12px rgba(242, 177, 10, 0.08);
}

.brt-badge--luxury::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--brt-yellow);
  box-shadow: 0 0 8px var(--brt-yellow);
  animation: brt-pulse-glow 2.5s infinite;
}

@keyframes brt-pulse-glow {
  0%, 100% { opacity: 0.6; transform: scale(0.9); }
  50% { opacity: 1; transform: scale(1.2); }
}

/* ==========================================================================
   5. PRINT OPTIMIZATION STYLESHEET (@media print)
   ========================================================================== */
@media print {
  body.brt-body {
    background: #FFFFFF !important;
    color: #12223B !important;
    font-size: 11pt;
  }

  .brt-header,
  .brt-mobile-drawer,
  .brt-drawer-backdrop,
  .brt-floating-wa,
  .brt-back-to-top,
  .brt-cookie-banner,
  .brt-theme-btn,
  .brt-hamburger,
  .brt-btn--whatsapp,
  #theme-toggle {
    display: none !important;
  }

  .brt-card {
    border: 1px solid #CCCCCC !important;
    box-shadow: none !important;
    background: #FFFFFF !important;
    color: #000000 !important;
    page-break-inside: avoid;
  }

  .brt-table th {
    background: #EEEEEE !important;
    color: #000000 !important;
  }

  a {
    color: #12223B !important;
    text-decoration: underline;
  }
}