/* ==========================================================================
   Csharpp JSC — Corporate Design System & Interactive Stylesheet
   Unique Visual Innovations, Staggered Lazy Loading, Fluid Animations
   ========================================================================== */

:root {
  /* Core Brand Identity Colors */
  --c-primary: #0a3d62;
  --c-primary-light: #165b8c;
  --c-primary-dark: #06263e;
  --c-accent: #00b4d8;
  --c-accent-hover: #0096c7;
  --c-accent-glow: rgba(0, 180, 216, 0.25);
  --c-accent-glow-strong: rgba(0, 180, 216, 0.45);
  
  /* Light Theme (Default) */
  --c-bg: #ffffff;
  --c-surface: #f8fafc;
  --c-surface-card: #ffffff;
  --c-surface-hover: #f1f5f9;
  --c-text: #0f172a;
  --c-text-muted: #475569;
  --c-text-subtle: #64748b;
  --c-border: #e2e8f0;
  --c-border-hover: #cbd5e1;
  --c-badge-bg: #e0f2fe;
  --c-badge-text: #0369a1;
  --c-grid-line: rgba(10, 61, 98, 0.04);
  --card-spotlight: rgba(0, 180, 216, 0.08);

  /* Radius & Shadows */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-full: 9999px;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05), 0 1px 2px rgba(0, 0, 0, 0.03);
  --shadow-md: 0 4px 16px -2px rgba(10, 61, 98, 0.08), 0 2px 6px -1px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 12px 32px -4px rgba(10, 61, 98, 0.12), 0 4px 12px -2px rgba(0, 0, 0, 0.05);
  --shadow-glow: 0 0 28px var(--c-accent-glow);

  /* Typography & Layout */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  --header-height: 76px;
  --container-max: 1200px;
  --transition-fast: 0.15s ease;
  --transition-normal: 0.28s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Explicit Dark Theme */
[data-theme="dark"] {
  --c-bg: #07121e;
  --c-surface: #0c1c2e;
  --c-surface-card: #0f243b;
  --c-surface-hover: #173352;
  --c-text: #f8fafc;
  --c-text-muted: #94a3b8;
  --c-text-subtle: #64748b;
  --c-border: #1e3a5f;
  --c-border-hover: #2a507f;
  --c-badge-bg: rgba(0, 180, 216, 0.15);
  --c-badge-text: #38bdf8;
  --c-grid-line: rgba(0, 180, 216, 0.06);
  --card-spotlight: rgba(0, 180, 216, 0.12);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.55);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --c-bg: #07121e;
    --c-surface: #0c1c2e;
    --c-surface-card: #0f243b;
    --c-surface-hover: #173352;
    --c-text: #f8fafc;
    --c-text-muted: #94a3b8;
    --c-text-subtle: #64748b;
    --c-border: #1e3a5f;
    --c-border-hover: #2a507f;
    --c-badge-bg: rgba(0, 180, 216, 0.15);
    --c-badge-text: #38bdf8;
    --c-grid-line: rgba(0, 180, 216, 0.06);
    --card-spotlight: rgba(0, 180, 216, 0.12);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.35);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.55);
  }
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
  font-family: var(--font-sans);
  background-color: var(--c-bg);
  color: var(--c-text);
  line-height: 1.6;
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  position: relative;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

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

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

/* ==================== SCROLL PROGRESS INDICATOR ==================== */
.scroll-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--c-primary), var(--c-accent), #38bdf8);
  z-index: 1100;
  box-shadow: 0 0 10px var(--c-accent);
  transition: width 0.1s linear;
}

/* Layout Utilities */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 100px 0;
  position: relative;
}

.section-alt {
  background-color: var(--c-surface);
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 60px;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background-color: var(--c-badge-bg);
  color: var(--c-badge-text);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 16px;
  border: 1px solid rgba(0, 180, 216, 0.2);
  box-shadow: 0 2px 8px rgba(0, 180, 216, 0.1);
}

.section-title {
  font-size: 2.35rem;
  font-weight: 850;
  line-height: 1.25;
  color: var(--c-text);
  margin-bottom: 16px;
  letter-spacing: -0.025em;
}

.section-desc {
  font-size: 1.125rem;
  color: var(--c-text-muted);
  line-height: 1.68;
}

/* Modern Button Component */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 26px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all var(--transition-normal);
  white-space: nowrap;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background-color: var(--c-accent);
  color: #ffffff;
  box-shadow: 0 4px 16px rgba(0, 180, 216, 0.35);
}

.btn-primary:hover {
  background-color: var(--c-accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 180, 216, 0.5);
}

.btn-secondary {
  background-color: transparent;
  border-color: var(--c-border);
  color: var(--c-text);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  background-color: var(--c-surface-hover);
  border-color: var(--c-accent);
  color: var(--c-accent);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 8px 18px;
  font-size: 0.875rem;
  border-radius: var(--radius-sm);
}

/* ==================== 1. STICKY HEADER ==================== */
.header {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background-color: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  z-index: 1000;
  border-bottom: 1px solid var(--c-border);
  transition: all var(--transition-normal);
}

[data-theme="dark"] .header,
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .header {
    background-color: rgba(7, 18, 30, 0.85);
  }
}

.header[data-scrolled="true"] {
  box-shadow: var(--shadow-md);
  height: 68px;
  border-bottom-color: rgba(0, 180, 216, 0.25);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-logo-img {
  height: 42px;
  width: auto;
  transition: height var(--transition-normal);
}

.header[data-scrolled="true"] .brand-logo-img {
  height: 36px;
}

.nav-desktop {
  display: none;
  align-items: center;
  gap: 28px;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--c-text-muted);
  position: relative;
  padding: 6px 0;
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--c-accent);
  transition: width var(--transition-fast);
}

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

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.control-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  color: var(--c-text);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-weight: 700;
  font-size: 0.8rem;
}

.control-btn:hover {
  background: var(--c-surface-hover);
  border-color: var(--c-accent);
  color: var(--c-accent);
}

.lang-switch-btn {
  width: auto;
  padding: 0 12px;
  font-weight: 750;
  letter-spacing: 0.06em;
}

.mobile-menu-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.mobile-menu-toggle span {
  width: 24px;
  height: 2px;
  background-color: var(--c-text);
  border-radius: 2px;
  transition: all var(--transition-normal);
}

.mobile-menu-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.mobile-menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.mobile-drawer {
  position: fixed;
  top: var(--header-height);
  left: 0;
  width: 100%;
  height: calc(100vh - var(--header-height));
  background-color: var(--c-bg);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transform: translateX(-100%);
  transition: transform var(--transition-slow);
  z-index: 999;
  border-top: 1px solid var(--c-border);
  overflow-y: auto;
}

.mobile-drawer.open {
  transform: translateX(0);
}

.mobile-nav-link {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--c-text);
  padding: 12px 0;
  border-bottom: 1px solid var(--c-border);
}

/* ==================== 2. HERO SECTION & LIVE CANVAS ==================== */
.hero {
  padding: 130px 0 90px;
  position: relative;
  overflow: hidden;
  background: radial-gradient(circle at 75% 25%, rgba(0, 180, 216, 0.12), transparent 50%),
              radial-gradient(circle at 15% 75%, rgba(10, 61, 98, 0.16), transparent 45%);
}

.hero-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
  opacity: 0.65;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 52px;
  align-items: center;
  position: relative;
  z-index: 2;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 18px;
  background-color: var(--c-badge-bg);
  color: var(--c-badge-text);
  border-radius: var(--radius-full);
  font-size: 0.92rem;
  font-weight: 650;
  margin-bottom: 24px;
  border: 1px solid rgba(0, 180, 216, 0.3);
  box-shadow: 0 0 16px var(--c-accent-glow);
}

.hero-title {
  font-size: 2.85rem;
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -0.035em;
  color: var(--c-text);
  margin-bottom: 24px;
}

.hero-title span {
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

[data-theme="dark"] .hero-title span,
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .hero-title span {
    background: linear-gradient(135deg, #38bdf8 0%, #00b4d8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
  }
}

.hero-desc {
  font-size: 1.22rem;
  color: var(--c-text-muted);
  line-height: 1.65;
  margin-bottom: 36px;
  max-width: 600px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 40px;
}

.hero-trust-list {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  font-size: 0.92rem;
  color: var(--c-text-subtle);
  border-top: 1px solid var(--c-border);
  padding-top: 24px;
}

.hero-trust-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
}

.hero-trust-item svg {
  color: #10b981;
}

/* Interactive 3D Perspective Tilt Card */
.hero-card-perspective-wrap {
  perspective: 1000px;
}

.hero-card-preview {
  position: relative;
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-xl);
  padding: 32px;
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(12px);
  transform-style: preserve-3d;
  transition: transform 0.15s ease-out, border-color var(--transition-fast), box-shadow var(--transition-normal);
  overflow: hidden;
}

.hero-card-preview::before {
  content: '';
  position: absolute;
  inset: -1px;
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, var(--c-accent), transparent 60%);
  z-index: -1;
  opacity: 0.5;
}

.preview-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--c-border);
}

.preview-dots {
  display: flex;
  gap: 6px;
}

.preview-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.preview-dot:nth-child(1) { background: #ef4444; }
.preview-dot:nth-child(2) { background: #f59e0b; }
.preview-dot:nth-child(3) { background: #10b981; }

.preview-status {
  font-size: 0.825rem;
  font-weight: 600;
  color: #10b981;
  display: flex;
  align-items: center;
  gap: 8px;
}

.pulse-dot {
  width: 8px;
  height: 8px;
  background-color: #10b981;
  border-radius: 50%;
  box-shadow: 0 0 10px #10b981;
  animation: pulse-glow 2s infinite ease-in-out;
}

@keyframes pulse-glow {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.4); opacity: 0.6; }
}

/* Interactive Tabs inside Hero Preview Card */
.preview-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--c-border);
  padding-bottom: 10px;
}

.preview-tab-btn {
  background: transparent;
  border: none;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 650;
  color: var(--c-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.preview-tab-btn:hover {
  color: var(--c-text);
  background: var(--c-surface-hover);
}

.preview-tab-btn.active {
  background: var(--c-badge-bg);
  color: var(--c-accent);
}

/* Telemetry Stream Output */
.telemetry-stream-box {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--c-text-muted);
  margin-bottom: 24px;
  min-height: 100px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  overflow: hidden;
}

.telemetry-line {
  display: flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
}

.telemetry-tag {
  color: #10b981;
  font-weight: 700;
}

.preview-metric-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-bottom: 20px;
}

.preview-metric-box {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  padding: 16px;
  transition: border-color var(--transition-fast);
}

.preview-metric-box:hover {
  border-color: var(--c-accent);
}

.preview-metric-num {
  font-size: 1.85rem;
  font-weight: 850;
  color: var(--c-accent);
  font-variant-numeric: tabular-nums;
}

.preview-metric-label {
  font-size: 0.85rem;
  color: var(--c-text-muted);
  font-weight: 500;
}

/* ==================== 3. TRUST BAR MARQUEE ==================== */
.trust-bar {
  padding: 42px 0;
  border-top: 1px solid var(--c-border);
  border-bottom: 1px solid var(--c-border);
  background: var(--c-surface);
  overflow: hidden;
  position: relative;
}

.trust-bar-label {
  text-align: center;
  font-size: 0.82rem;
  font-weight: 750;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--c-text-subtle);
  margin-bottom: 24px;
}

.trust-marquee {
  display: flex;
  overflow: hidden;
  user-select: none;
  mask-image: linear-gradient(to right, transparent 0%, black 10%, black 90%, transparent 100%);
  -webkit-mask-image: linear-gradient(to right, transparent 0%, black 10%, black 90%, transparent 100%);
}

.trust-marquee-track {
  display: flex;
  gap: 20px;
  flex-shrink: 0;
  animation: marquee-scroll 32s linear infinite;
}

.trust-marquee:hover .trust-marquee-track {
  animation-play-state: paused;
}

@keyframes marquee-scroll {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

.trust-badge {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 22px;
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  font-size: 0.92rem;
  font-weight: 650;
  color: var(--c-text);
  white-space: nowrap;
  transition: all var(--transition-fast);
}

.trust-badge:hover {
  border-color: var(--c-accent);
  box-shadow: 0 4px 14px var(--c-accent-glow);
  transform: translateY(-2px);
}

.trust-badge-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #10b981;
  box-shadow: 0 0 6px #10b981;
}

/* ==================== 4. SERVICES SPOTLIGHT CARDS ==================== */
.services-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

.service-card {
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-xl);
  padding: 42px;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-fast);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

/* Mouse Spotlight Effect */
.service-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(400px circle at var(--mouse-x, 50%) var(--mouse-y, 50%), var(--card-spotlight), transparent 80%);
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
  z-index: 1;
}

.service-card:hover::before {
  opacity: 1;
}

.service-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: var(--c-accent);
}

.service-icon-wrapper {
  width: 68px;
  height: 68px;
  border-radius: var(--radius-md);
  background: var(--c-badge-bg);
  color: var(--c-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 26px;
  border: 1px solid rgba(0, 180, 216, 0.2);
  transition: transform var(--transition-normal);
}

.service-card:hover .service-icon-wrapper {
  transform: scale(1.08) rotate(3deg);
}

.service-title {
  font-size: 1.55rem;
  font-weight: 850;
  margin-bottom: 16px;
  color: var(--c-text);
  letter-spacing: -0.02em;
}

.service-desc {
  font-size: 1.02rem;
  color: var(--c-text-muted);
  margin-bottom: 24px;
  line-height: 1.65;
}

.service-features {
  list-style: none;
  margin-bottom: 28px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.service-feature-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 0.95rem;
  color: var(--c-text);
  font-weight: 500;
}

.service-feature-item svg {
  color: var(--c-accent);
  flex-shrink: 0;
  margin-top: 4px;
}

/* Architecture Spec Drawer inside Card */
.arch-preview-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: transparent;
  border: 1px dashed var(--c-border);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 650;
  color: var(--c-accent);
  cursor: pointer;
  margin-bottom: 24px;
  transition: all var(--transition-fast);
}

.arch-preview-btn:hover {
  background: var(--c-surface-hover);
  border-color: var(--c-accent);
}

.arch-spec-drawer {
  display: none;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  padding: 16px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--c-text-muted);
  margin-bottom: 24px;
  line-height: 1.5;
  animation: fadeIn 0.3s ease;
}

.arch-spec-drawer.open {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}

.service-link {
  margin-top: auto;
  font-weight: 750;
  font-size: 0.98rem;
  color: var(--c-accent);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: gap var(--transition-fast);
}

.service-link:hover {
  gap: 14px;
}

/* ==================== 5. NUMBERS & STATS WITH DYNAMIC COUNTER ==================== */
.stats-section {
  background: linear-gradient(135deg, var(--c-primary-dark) 0%, var(--c-primary) 100%);
  color: #ffffff;
  padding: 90px 0;
  position: relative;
  overflow: hidden;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 36px;
  text-align: center;
}

.stat-item {
  padding: 24px;
  position: relative;
}

.stat-gauge-wrap {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.stat-number {
  font-size: 3.65rem;
  font-weight: 900;
  line-height: 1;
  color: #38bdf8;
  margin-bottom: 12px;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  text-shadow: 0 0 20px rgba(56, 189, 248, 0.4);
}

.stat-label {
  font-size: 1.15rem;
  font-weight: 700;
  color: #e0f2fe;
}

.stat-desc {
  font-size: 0.9rem;
  color: #93c5fd;
  margin-top: 6px;
}

/* ==================== 6. CASE STUDIES WITH BEFORE / AFTER TOGGLE ==================== */
.cases-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
}

.case-card {
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-xl);
  padding: 38px;
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
  position: relative;
}

.case-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: var(--c-accent);
}

.case-top-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.case-badge {
  padding: 4px 14px;
  border-radius: var(--radius-full);
  font-size: 0.82rem;
  font-weight: 750;
  background: var(--c-badge-bg);
  color: var(--c-badge-text);
  border: 1px solid rgba(0, 180, 216, 0.2);
}

/* Before / After Switch Pills */
.case-toggle-bar {
  display: flex;
  gap: 4px;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-full);
  padding: 3px;
}

.case-toggle-btn {
  background: transparent;
  border: none;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--c-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.case-toggle-btn.active {
  background: var(--c-surface-card);
  color: var(--c-accent);
  box-shadow: var(--shadow-sm);
}

.case-title {
  font-size: 1.4rem;
  font-weight: 850;
  margin-bottom: 22px;
  color: var(--c-text);
  line-height: 1.35;
}

.case-view-panel {
  min-height: 120px;
  margin-bottom: 20px;
  transition: opacity 0.2s ease;
}

.case-stat-highlight-box {
  margin-top: auto;
  padding-top: 22px;
  border-top: 1px solid var(--c-border);
  display: flex;
  align-items: center;
  gap: 18px;
}

.case-stat-num {
  font-size: 1.75rem;
  font-weight: 850;
  color: #10b981;
}

.case-stat-desc {
  font-size: 0.88rem;
  font-weight: 650;
  color: var(--c-text-muted);
}

/* ==================== 7. TECH STACK WITH CATEGORY FILTER ==================== */
.tech-filter-bar {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-bottom: 40px;
}

.tech-filter-btn {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-full);
  padding: 8px 20px;
  font-size: 0.9rem;
  font-weight: 650;
  color: var(--c-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.tech-filter-btn:hover {
  color: var(--c-text);
  border-color: var(--c-accent);
}

.tech-filter-btn.active {
  background: var(--c-accent);
  color: #ffffff;
  border-color: var(--c-accent);
  box-shadow: 0 4px 14px rgba(0, 180, 216, 0.35);
}

.tech-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.tech-card {
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 28px 20px;
  text-align: center;
  transition: transform var(--transition-normal), border-color var(--transition-fast), box-shadow var(--transition-normal);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  position: relative;
}

.tech-card:hover {
  transform: translateY(-6px) scale(1.02);
  border-color: var(--c-accent);
  box-shadow: var(--shadow-glow);
}

.tech-icon {
  width: 52px;
  height: 52px;
  transition: transform var(--transition-normal);
}

.tech-card:hover .tech-icon {
  transform: scale(1.12);
}

.tech-name {
  font-weight: 800;
  font-size: 1.1rem;
  color: var(--c-text);
}

.tech-tag {
  font-size: 0.825rem;
  color: var(--c-text-muted);
}

/* ==================== 8. CONNECTED PIPELINE PROCESS ==================== */
.process-container-wrap {
  position: relative;
}

.process-timeline {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  position: relative;
  margin-bottom: 36px;
}

.process-step {
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  position: relative;
  display: flex;
  gap: 20px;
  align-items: flex-start;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.process-step:hover {
  border-color: var(--c-accent);
  transform: translateY(-3px);
}

.process-step.active {
  border-color: var(--c-accent);
  box-shadow: 0 6px 20px var(--c-accent-glow);
  background: linear-gradient(145deg, var(--c-surface-card), var(--c-surface));
}

.step-num {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--c-primary);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
  font-size: 1.15rem;
  flex-shrink: 0;
  border: 2px solid transparent;
  transition: all var(--transition-normal);
}

.process-step.active .step-num {
  background: var(--c-accent);
  box-shadow: 0 0 16px var(--c-accent);
}

.step-title {
  font-size: 1.25rem;
  font-weight: 850;
  margin-bottom: 8px;
  color: var(--c-text);
}

.step-desc {
  font-size: 0.95rem;
  color: var(--c-text-muted);
  line-height: 1.6;
}

/* Deliverable Artifact Inspector */
.deliverable-inspector-card {
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 28px 36px;
  box-shadow: var(--shadow-md);
  border-left: 4px solid var(--c-accent);
  animation: fadeIn 0.3s ease;
}

.deliverable-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.deliverable-checklist {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.deliverable-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--c-text);
}

.deliverable-item svg {
  color: #10b981;
}

/* ==================== 9. WHY US (BENTO & COMPARISON TABLE) ==================== */
.why-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-bottom: 60px;
}

.why-card {
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 34px;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.why-card:hover {
  transform: translateY(-5px);
  border-color: var(--c-accent);
  box-shadow: var(--shadow-md);
}

.why-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  background: var(--c-badge-bg);
  color: var(--c-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 22px;
  border: 1px solid rgba(0, 180, 216, 0.2);
}

.why-title {
  font-size: 1.3rem;
  font-weight: 850;
  margin-bottom: 12px;
  color: var(--c-text);
}

.why-desc {
  font-size: 0.98rem;
  color: var(--c-text-muted);
  line-height: 1.65;
}

/* Interactive Comparison Matrix */
.comparison-section-header {
  text-align: center;
  margin-bottom: 32px;
}

.comparison-table-wrapper {
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-xl);
  overflow-x: auto;
  box-shadow: var(--shadow-md);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 600px;
}

.comparison-table th, .comparison-table td {
  padding: 18px 24px;
  text-align: left;
  border-bottom: 1px solid var(--c-border);
}

.comparison-table th {
  background: var(--c-surface);
  font-weight: 800;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--c-text);
}

.comparison-table th.csharpp-col {
  color: var(--c-accent);
  background: rgba(0, 180, 216, 0.08);
}

.comparison-table td.csharpp-col {
  background: rgba(0, 180, 216, 0.03);
  font-weight: 700;
  color: var(--c-text);
}

/* ==================== 10. CONTACT FORM & INTERACTIVE ESTIMATOR ==================== */
.contact-section {
  background: radial-gradient(circle at 10% 20%, rgba(0, 180, 216, 0.08), transparent 40%),
              radial-gradient(circle at 90% 80%, rgba(10, 61, 98, 0.08), transparent 40%);
}

.contact-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
}

/* Interactive Project Estimator Widget */
.estimator-card {
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-xl);
  padding: 32px;
  margin-bottom: 32px;
  box-shadow: var(--shadow-sm);
}

.estimator-title {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.estimator-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
}

.estimator-pill {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  padding: 8px 16px;
  font-size: 0.85rem;
  font-weight: 650;
  color: var(--c-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.estimator-pill:hover {
  border-color: var(--c-accent);
  color: var(--c-text);
}

.estimator-pill.active {
  background: var(--c-badge-bg);
  border-color: var(--c-accent);
  color: var(--c-accent);
}

.estimator-result-box {
  background: var(--c-surface);
  border-left: 3px solid var(--c-accent);
  padding: 12px 18px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 0.9rem;
  color: var(--c-text);
}

.contact-info-card {
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-xl);
  padding: 40px;
  height: 100%;
}

.contact-info-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-top: 32px;
}

.contact-info-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.contact-icon-box {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: var(--c-badge-bg);
  color: var(--c-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.contact-form-card {
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-xl);
  padding: 40px;
  box-shadow: var(--shadow-lg);
}

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

.form-label {
  display: block;
  font-size: 0.92rem;
  font-weight: 650;
  margin-bottom: 8px;
  color: var(--c-text);
}

.form-input, .form-select, .form-textarea {
  width: 100%;
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--c-border);
  background: var(--c-surface);
  color: var(--c-text);
  font-size: 0.95rem;
  transition: all var(--transition-fast);
}

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

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

.form-alert {
  display: none;
  padding: 16px 20px;
  border-radius: var(--radius-md);
  margin-bottom: 24px;
  font-size: 0.95rem;
  font-weight: 600;
  animation: fadeIn 0.3s ease;
}

.form-alert.success {
  display: flex;
  align-items: center;
  gap: 12px;
  background-color: #ecfdf5;
  color: #065f46;
  border: 1px solid #a7f3d0;
}

[data-theme="dark"] .form-alert.success,
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .form-alert.success {
    background-color: rgba(16, 185, 129, 0.2);
    color: #6ee7b7;
    border-color: rgba(16, 185, 129, 0.4);
  }
}

/* ==================== 11. FOOTER & LIVE HANOI CLOCK ==================== */
.footer {
  background-color: var(--c-surface);
  border-top: 1px solid var(--c-border);
  padding: 80px 0 36px;
  position: relative;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  margin-bottom: 60px;
}

.footer-col-title {
  font-size: 1.05rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 20px;
  color: var(--c-text);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links a {
  font-size: 0.95rem;
  color: var(--c-text-muted);
}

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

.hanoi-clock-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-full);
  font-family: var(--font-mono);
  font-size: 0.825rem;
  color: var(--c-text-muted);
  margin-top: 18px;
}

.footer-bottom {
  border-top: 1px solid var(--c-border);
  padding-top: 32px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  align-items: center;
  text-align: center;
  font-size: 0.88rem;
  color: var(--c-text-subtle);
}

/* Back to Top with Circular Progress Indicator */
.scroll-top-btn {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--c-surface-card);
  border: 1px solid var(--c-border);
  color: var(--c-text);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: all var(--transition-normal);
  z-index: 1050;
}

.scroll-top-btn.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.scroll-top-btn:hover {
  border-color: var(--c-accent);
  color: var(--c-accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}

.scroll-top-progress-ring {
  position: absolute;
  top: 0;
  left: 0;
  transform: rotate(-90deg);
}

.scroll-top-progress-ring circle {
  stroke-dasharray: 140;
  stroke-dashoffset: 140;
  transition: stroke-dashoffset 0.1s linear;
}

/* ==================== SCROLL REVEAL LAZY ANIMATIONS ==================== */
.reveal {
  opacity: 0;
  transition: opacity var(--transition-slow), transform var(--transition-slow);
  will-change: opacity, transform;
}

/* Stagger & Directional Variants */
.reveal[data-reveal="fade-up"] { transform: translateY(32px); }
.reveal[data-reveal="fade-down"] { transform: translateY(-32px); }
.reveal[data-reveal="fade-left"] { transform: translateX(36px); }
.reveal[data-reveal="fade-right"] { transform: translateX(-36px); }
.reveal[data-reveal="zoom-in"] { transform: scale(0.92); }
.reveal[data-reveal="flip"] { transform: perspective(800px) rotateX(20deg); }

.reveal.visible {
  opacity: 1;
  transform: none;
}

/* Responsive Rules */
@media (min-width: 640px) {
  .preview-metric-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  .deliverable-checklist {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 768px) {
  .section-title {
    font-size: 2.85rem;
  }
  .nav-desktop {
    display: flex;
  }
  .mobile-menu-toggle {
    display: none;
  }
  .services-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .stats-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  .cases-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .tech-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  .process-timeline {
    grid-template-columns: repeat(5, 1fr);
    gap: 16px;
  }
  .process-step {
    flex-direction: column;
    padding: 24px;
  }
  .why-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .contact-layout {
    grid-template-columns: 1fr 1.35fr;
  }
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
  }
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
  }
}

@media (min-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1.15fr 0.85fr;
  }
  .hero-title {
    font-size: 3.5rem;
  }
}