/* ==========================================================================
   CORPORATE IT WEBSITE - SILICON VALLEY DESIGN SYSTEM (LINEAR / VERCEL / STRIPE)
   Supports Dark Mode & Light Mode + Dynamic Brand Color Variables
   ========================================================================== */

:root {
  --brand-primary: #4f46e5;       /* Indigo 600 */
  --brand-primary-light: #6366f1; /* Indigo 500 */
  --brand-secondary: #06b6d4;     /* Cyan 500 */
  --brand-accent: #8b5cf6;        /* Violet 500 */
  --bg-main: #f8fafc;
  --bg-surface: #ffffff;
  --bg-elevated: #f1f5f9;
  --text-main: #0f172a;
  --text-muted: #475569;
  --border-color: rgba(148, 163, 184, 0.22);
  --card-shadow: 0 10px 30px -10px rgba(15, 23, 42, 0.06);
  --glow-opacity: 0.15;
}

.dark {
  --bg-main: #050814;
  --bg-surface: #0b1124;
  --bg-elevated: #111936;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --border-color: rgba(148, 163, 184, 0.12);
  --card-shadow: 0 20px 40px -15px rgba(0, 0, 0, 0.6);
  --glow-opacity: 0.28;
}

* {
  box-sizing: border-box;
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: var(--bg-main);
  color: var(--text-main);
  transition: background-color 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
}

/* Tech Grid Background */
.bg-tech-grid {
  background-size: 44px 44px;
  background-image: 
    linear-gradient(to right, var(--border-color) 1px, transparent 1px),
    linear-gradient(to bottom, var(--border-color) 1px, transparent 1px);
  mask-image: radial-gradient(ellipse 80% 70% at 50% 25%, #000 55%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 80% 70% at 50% 25%, #000 55%, transparent 100%);
}

/* Ambient Hero Glow */
.hero-glow {
  position: absolute;
  width: 680px;
  height: 420px;
  background: radial-gradient(circle, var(--brand-primary) 0%, var(--brand-secondary) 45%, transparent 70%);
  filter: blur(110px);
  opacity: var(--glow-opacity);
  pointer-events: none;
  z-index: 0;
}

/* Brand Gradient Utilities */
.text-brand-gradient {
  background: linear-gradient(135deg, var(--brand-primary-light) 0%, var(--brand-secondary) 55%, var(--brand-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.bg-brand-gradient {
  background: linear-gradient(135deg, var(--brand-primary) 0%, var(--brand-secondary) 100%);
}

.border-brand-glow:hover {
  border-color: var(--brand-primary-light);
  box-shadow: 0 0 28px -6px rgba(99, 102, 241, 0.35);
}

/* Glassmorphism Cards */
.glass-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  box-shadow: var(--card-shadow);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  transition: all 0.28s cubic-bezier(0.16, 1, 0.3, 1);
}

.dark .glass-card {
  background: rgba(13, 20, 42, 0.72);
}

.glass-card:hover {
  border-color: rgba(99, 102, 241, 0.45);
}

/* Chỉ card bấm được mới nổi lên khi rê chuột (form, popup... đứng yên khi đang gõ) */
.glass-card.cursor-pointer:hover {
  transform: translateY(-4px);
}

/* Tôn trọng cài đặt "Giảm chuyển động" của hệ điều hành */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

.glass-nav {
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
}

.dark .glass-nav {
  background: rgba(5, 8, 20, 0.82);
}

/* Page Section Transitions */
.page-section {
  display: none;
  animation: fadeInPage 0.38s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.page-section.active {
  display: block;
}

@keyframes fadeInPage {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Floating Animation for Hero Visuals */
@keyframes floatSlow {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-10px); }
}

.animate-float {
  animation: floatSlow 6s ease-in-out infinite;
}

/* Pulse Dot */
@keyframes pulseRing {
  0% { transform: scale(0.9); opacity: 0.8; }
  70% { transform: scale(1.8); opacity: 0; }
  100% { transform: scale(0.9); opacity: 0; }
}

.pulse-dot::before {
  content: '';
  position: absolute;
  inset: -4px;
  border-radius: 9999px;
  background-color: #10b981;
  animation: pulseRing 2s infinite;
}

/* Official Card Badge Indicator */
.placeholder-tag {
  border: 1px solid var(--border-color);
  position: relative;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-main);
}

::-webkit-scrollbar-thumb {
  background: rgba(148, 163, 184, 0.35);
  border-radius: 9999px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--brand-primary-light);
}