/* ═══════════════════════════════════════════════════════════
   CASE STUDY 04 — PREMIUM BRAND IDENTITY
   Theme: Obsidian Studio, Spatial Grids, Fluid Motion
   ═══════════════════════════════════════════════════════════ */

:root {
  --cs4-bg-dark: #030303;
  --cs4-bg-obsidian: #0a0a0a;
  --cs4-bg-card: rgba(18, 18, 18, 0.6);
  
  --cs4-text-primary: #ffffff;
  --cs4-text-secondary: #a1a1aa;
  --cs4-text-dim: #52525b;
  
  --cs4-grid-line: rgba(255, 255, 255, 0.06);
  
  /* 4 Premium Neon Colors */
  --cs4-color-1: #eab308; /* Neon Gold */
  --cs4-color-2: #3b82f6; /* Neon Blue */
  --cs4-color-3: #ec4899; /* Neon Magenta */
  --cs4-color-4: #10b981; /* Neon Emerald */
  
  --cs4-accent-neon: var(--cs4-color-1); /* Fallback/Default */
  
  --cs4-font-sans: 'Inter', sans-serif;
  --cs4-font-serif: 'Outfit', sans-serif; /* Using Outfit as the sleek header font */
}

html { scroll-behavior: smooth; }

body.cs4-body {
  margin: 0;
  padding: 0;
  background-color: var(--cs4-bg-dark);
  color: var(--cs4-text-primary);
  font-family: var(--cs4-font-sans);
  overflow-x: hidden;
  position: relative;
}

/* ─── Background Studio Grid ─── */
.cs4-bg-grid {
  position: fixed;
  inset: 0;
  background-image: 
    linear-gradient(to right, var(--cs4-grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--cs4-grid-line) 1px, transparent 1px);
  background-size: 100px 100px;
  z-index: -2;
  pointer-events: none;
}
.cs4-bg-gradient {
  position: fixed;
  inset: 0;
  background: radial-gradient(circle at 50% 0%, rgba(255,255,255,0.03) 0%, transparent 70%);
  z-index: -1;
  pointer-events: none;
}

/* ─── Navigation ─── */
.cs4-nav {
  position: fixed;
  top: 0;
  width: 100%;
  padding: 24px 5%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 100;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: rgba(3, 3, 3, 0.8);
  border-bottom: 1px solid var(--cs4-grid-line);
  box-sizing: border-box;
}

.cs4-back-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--cs4-text-secondary);
  text-decoration: none;
  font-size: 0.85rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  transition: color 0.3s;
}
.cs4-back-btn:hover { color: var(--cs4-text-primary); }

/* ─── Layout ─── */
.cs4-layout {
  display: flex;
  min-height: 100vh;
  position: relative;
}

/* ─── Fluid Line Thread (Left Margin) ─── */
.cs4-thread-container {
  width: 100px;
  flex-shrink: 0;
  position: relative;
  display: none;
}
@media (min-width: 1024px) {
  .cs4-thread-container { display: block; }
}
.cs4-thread-svg {
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 2px;
  height: 100%;
  overflow: visible;
}
.cs4-thread-path {
  fill: none;
  stroke: var(--cs4-accent-neon);
  stroke-width: 2;
  stroke-linecap: round;
  filter: drop-shadow(0 0 8px var(--cs4-accent-neon));
}

/* ─── Main Content Area ─── */
.cs4-content {
  flex-grow: 1;
  padding: 180px 5% 100px;
  max-width: 1200px;
  margin: 0 auto;
}

/* ─── Text-Mask Glides (System 1) ─── */
.tm-wrap {
  display: inline-block;
  overflow: hidden;
  vertical-align: bottom;
}
.tm-inner {
  display: inline-block;
  transform: translateY(110%);
  transition: transform 1s cubic-bezier(0.25, 1, 0.5, 1);
}
.tm-wrap.visible .tm-inner {
  transform: translateY(0);
}

/* ─── Typography ─── */
.cs4-hero-heading-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-bottom: 40px;
}
.cs4-h1 {
  font-family: var(--cs4-font-serif);
  font-size: clamp(2.5rem, 5vw, 4.5rem);
  font-weight: 300;
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin-bottom: 0;
  background: linear-gradient(135deg, #ffffff 0%, #eab308 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  color: transparent;
}
.cs4-h2 {
  font-family: var(--cs4-font-serif);
  font-size: clamp(2rem, 3vw, 3rem);
  font-weight: 300;
  margin-bottom: 40px;
  color: var(--cs4-text-primary);
}
.cs4-h3 {
  font-family: var(--cs4-font-sans);
  font-size: 1.25rem;
  font-weight: 400;
  color: var(--cs4-text-primary);
  margin-bottom: 16px;
  letter-spacing: 0.02em;
}
.cs4-p {
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--cs4-text-secondary);
  margin-bottom: 24px;
}
.cs4-label {
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cs4-accent-neon);
  margin-bottom: 24px;
  display: block;
}

/* ─── Gallery Placeholder Grid ─── */
.cs4-gallery-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin: 60px 0;
}
@media (min-width: 768px) {
  .cs4-gallery-grid { grid-template-columns: 1fr 1fr; }
}

.cs4-gallery-item {
  aspect-ratio: 4/3;
  background: var(--cs4-bg-obsidian);
  border: 1px solid var(--cs4-grid-line);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--cs4-text-dim);
  font-size: 0.85rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* ─── 3D Spatial Grid Cards (System 3) ─── */
.cs4-3d-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  margin: 40px 0;
  perspective: 1000px;
}
@media (min-width: 768px) {
  .cs4-3d-grid { grid-template-columns: 1fr 1fr; }
}

.cs4-card-3d {
  background: var(--cs4-bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--cs4-grid-line);
  padding: 40px;
  border-radius: 8px;
  transform-style: preserve-3d;
  transition: transform 0.1s ease-out, border-color 0.4s, box-shadow 0.4s;
  will-change: transform;
}
.cs4-card-3d:hover {
  border-color: var(--cs4-color-2);
  box-shadow: 0 10px 40px rgba(59, 130, 246, 0.1);
}
.cs4-card-3d:nth-child(2):hover {
  border-color: var(--cs4-color-3);
  box-shadow: 0 10px 40px rgba(236, 72, 153, 0.1);
}
.cs4-card-3d:nth-child(3):hover {
  border-color: var(--cs4-color-4);
  box-shadow: 0 10px 40px rgba(16, 185, 129, 0.1);
}
.cs4-card-content {
  transform: translateZ(30px); /* Pushes content forward in 3D space */
}

/* ─── Interactive Asset Layering (System 4) ─── */
.cs4-asset-module {
  position: relative;
  width: 100%;
  aspect-ratio: 16/9;
  border: 1px solid var(--cs4-grid-line);
  border-radius: 8px;
  overflow: hidden;
  margin-bottom: 32px;
  cursor: crosshair;
}

/* Technical Layer (Underneath) */
.cs4-asset-tech {
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    45deg,
    transparent,
    transparent 10px,
    rgba(234, 179, 8, 0.05) 10px,
    rgba(234, 179, 8, 0.05) 20px
  ), #0a0a0a;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1;
}
.cs4-asset-tech-lines {
  position: absolute;
  inset: 20px;
  border: 1px dashed rgba(234, 179, 8, 0.3);
}

/* Presentation Layer (Top) */
.cs4-asset-present {
  position: absolute;
  inset: 0;
  background: #111;
  z-index: 2;
  transition: transform 0.6s cubic-bezier(0.25, 1, 0.5, 1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--cs4-text-secondary);
  font-size: 0.9rem;
  letter-spacing: 0.1em;
}
.cs4-asset-present img {
  transition: transform 0.6s cubic-bezier(0.25, 1, 0.5, 1);
}

/* Hover State: Scale image up */
.cs4-asset-module:hover .cs4-asset-present img {
  transform: scale(1.05);
}

/* ─── Lightbox Modal ─── */
.cs4-lightbox {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.9);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}
.cs4-lightbox.active {
  opacity: 1;
  pointer-events: all;
  cursor: zoom-out;
}
.cs4-lightbox img {
  max-width: 90vw;
  max-height: 90vh;
  object-fit: contain;
  border-radius: 4px;
  box-shadow: 0 0 40px rgba(0,0,0,0.5);
  transform: scale(0.95);
  transition: transform 0.3s cubic-bezier(0.25, 1, 0.5, 1);
}
.cs4-lightbox.active img {
  transform: scale(1);
}

/* ─── Graphic Design Decorative Elements ─── */
.cs4-vector-element {
  position: absolute;
  pointer-events: none;
  opacity: 0.15;
  z-index: 0;
  color: var(--cs4-accent-neon);
}

/* ─── Utilities & Color Integration ─── */
.cs4-section { margin-bottom: 120px; position: relative; }

/* 4-Color Gradient Divider */
.cs4-hr {
  border: none;
  height: 2px;
  background: linear-gradient(90deg, var(--cs4-color-2), var(--cs4-color-3), var(--cs4-color-4), var(--cs4-color-1));
  margin: 80px 0;
  opacity: 0.5;
  filter: drop-shadow(0 0 8px rgba(236, 72, 153, 0.4));
}

/* Color Classes for Labels/Text */
.c-gold { color: var(--cs4-color-1) !important; }
.c-blue { color: var(--cs4-color-2) !important; }
.c-magenta { color: var(--cs4-color-3) !important; }
.c-emerald { color: var(--cs4-color-4) !important; }

/* ─── Motion Graphic Animations ─── */
@keyframes spinSlow {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}
@keyframes floatGentle {
  0% { transform: translateY(0); }
  50% { transform: translateY(-15px); }
  100% { transform: translateY(0); }
}
@keyframes pulseGlow {
  0% { transform: scale(0.95); opacity: 0.1; }
  50% { transform: scale(1.05); opacity: 0.3; }
  100% { transform: scale(0.95); opacity: 0.1; }
}

.mg-spin {
  animation: spinSlow 15s linear infinite;
  transform-origin: center center;
  will-change: transform;
}
.mg-float {
  animation: floatGentle 6s ease-in-out infinite;
  will-change: transform;
}
.mg-pulse {
  animation: pulseGlow 4s ease-in-out infinite;
  transform-origin: center center;
  will-change: transform, opacity;
}