/* ============================================================
   GLOBAL DESIGN SYSTEM — style.css
   Portfolio: Pratap Patra | 2026
   ============================================================ */

/* ── Design Tokens (CSS Custom Properties) ── */
:root {
  /* ── Color Palette — Dark Mode (default) ── */
  --color-bg:          #0d0d14;
  --color-bg-2:        #13131f;
  --color-bg-card:     #1a1a2e;
  --color-bg-card-2:   #1e1e38;

  --color-text:        #f1f5f9;
  --color-text-2:      #94a3b8;
  --color-text-3:      #64748b;

  --color-accent:      #6366f1;
  --color-accent-2:    #8b5cf6;
  --color-accent-3:    #06b6d4;
  --color-success:     #10b981;
  --color-warning:     #f59e0b;
  --color-error:       #f43f5e;

  --gradient-accent:   linear-gradient(135deg, #6366f1, #8b5cf6);
  --gradient-hero:     linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #06b6d4 100%);
  --gradient-card:     linear-gradient(145deg, rgba(99,102,241,0.06), rgba(139,92,246,0.02));
  --gradient-glow:     radial-gradient(ellipse at center, rgba(99,102,241,0.12) 0%, transparent 70%);

  --border:            rgba(255, 255, 255, 0.07);
  --border-accent:     rgba(99, 102, 241, 0.35);

  --nav-glass:         rgba(13, 13, 20, 0.5);
  --nav-glass-scrolled: rgba(13, 13, 20, 0.88);

  --shadow-xs:   0 1px 2px rgba(0, 0, 0, 0.5);
  --shadow-sm:   0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow-md:   0 4px 20px rgba(0, 0, 0, 0.45);
  --shadow-lg:   0 8px 40px rgba(0, 0, 0, 0.55);
  --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.2);

  /* ── Typography ── */
  --font-body:    'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-heading: 'Space Grotesk', 'Inter', sans-serif;
  --font-mono:    'Fira Code', 'Cascadia Code', 'Consolas', monospace;

  /* ── Spacing Scale (8px base) ── */
  --sp-1:  0.25rem;
  --sp-2:  0.5rem;
  --sp-3:  0.75rem;
  --sp-4:  1rem;
  --sp-5:  1.25rem;
  --sp-6:  1.5rem;
  --sp-8:  2rem;
  --sp-10: 2.5rem;
  --sp-12: 3rem;
  --sp-16: 4rem;
  --sp-20: 5rem;
  --sp-24: 6rem;

  /* ── Border Radius ── */
  --r-sm:   0.375rem;
  --r-md:   0.75rem;
  --r-lg:   1rem;
  --r-xl:   1.5rem;
  --r-2xl:  2rem;
  --r-full: 9999px;

  /* ── Transitions ── */
  --ease-fast:   150ms cubic-bezier(0.4, 0, 0.2, 1);
  --ease-base:   250ms cubic-bezier(0.4, 0, 0.2, 1);
  --ease-slow:   400ms cubic-bezier(0.4, 0, 0.2, 1);
  --ease-spring: 600ms cubic-bezier(0.34, 1.56, 0.64, 1);

  /* ── Layout ── */
  --max-width: 1200px;
  --nav-h:     70px;

  /* ── Z-index Scale ── */
  --z-base:    1;
  --z-dropdown: 10;
  --z-sticky:  100;
  --z-overlay: 200;
  --z-modal:   300;
  --z-cursor:  9999;
}

/* ── Light Mode Token Overrides ── */
body.light-mode {
  --color-bg:          #f8fafc;
  --color-bg-2:        #f1f5f9;
  --color-bg-card:     #ffffff;
  --color-bg-card-2:   #f8fafc;

  --color-text:        #0f172a;
  --color-text-2:      #334155;
  --color-text-3:      #64748b;

  --border:            rgba(0, 0, 0, 0.08);
  --border-accent:     rgba(99, 102, 241, 0.3);

  --nav-glass:          rgba(248, 250, 252, 0.5);
  --nav-glass-scrolled: rgba(248, 250, 252, 0.92);

  --shadow-xs:   0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-sm:   0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md:   0 4px 20px rgba(0, 0, 0, 0.10);
  --shadow-lg:   0 8px 40px rgba(0, 0, 0, 0.12);
  --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.12);

  --gradient-card: linear-gradient(145deg, rgba(99,102,241,0.03), rgba(139,92,246,0.01));
  --gradient-glow: radial-gradient(ellipse at center, rgba(99,102,241,0.06) 0%, transparent 70%);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  transition: background-color var(--ease-slow), color var(--ease-slow);
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
img, video { max-width: 100%; height: auto; display: block; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input, textarea, select { font-family: inherit; }

/* ── Accessibility ── */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  border-radius: var(--r-sm);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

/* Skip to main content link */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--sp-4);
  z-index: var(--z-modal);
  background: var(--color-accent);
  color: white;
  padding: var(--sp-2) var(--sp-4);
  border-radius: var(--r-md);
  font-size: 0.9rem;
  font-weight: 600;
  transition: top var(--ease-fast);
}
.skip-link:focus { top: var(--sp-2); }

/* ── Text Selection ── */
::selection {
  background: rgba(99, 102, 241, 0.25);
  color: var(--color-text);
}

/* ── Custom Scrollbar ── */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: var(--color-bg-2); }
::-webkit-scrollbar-thumb {
  background: var(--color-accent);
  border-radius: var(--r-full);
}

/* ── Loading Screen ── */
.loader {
  position: fixed;
  inset: 0;
  background: var(--color-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal);
  transition: opacity 0.5s ease, visibility 0.5s ease;
}

.loader.loader--hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.loader__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--sp-5);
}

.loader__logo {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 800;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.04em;
}

.loader__bar {
  width: 200px;
  height: 2px;
  background: var(--border);
  border-radius: var(--r-full);
  overflow: hidden;
}

.loader__bar-fill {
  height: 100%;
  background: var(--gradient-accent);
  border-radius: var(--r-full);
  animation: loaderBar 1.4s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

/* ── Scroll Progress Bar ── */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--gradient-accent);
  z-index: calc(var(--z-sticky) + 1);
  transition: width 0.1s linear;
  border-radius: 0 var(--r-full) var(--r-full) 0;
}

/* ============================================================
   NAVIGATION
   ============================================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-h);
  z-index: var(--z-sticky);
  background: transparent;
  transition: background var(--ease-base), box-shadow var(--ease-base);
}

.navbar.navbar--scrolled {
  background: var(--nav-glass-scrolled);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.navbar__inner {
  max-width: var(--max-width);
  height: 100%;
  margin: 0 auto;
  padding: 0 var(--sp-8);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
}

/* Logo */
.navbar__logo {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 800;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
  letter-spacing: -0.03em;
  transition: opacity var(--ease-fast);
  flex-shrink: 0;
}
.navbar__logo:hover { opacity: 0.75; }

/* Desktop Links */
.navbar__links {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
  list-style: none;
}

.navbar__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  padding: var(--sp-2) var(--sp-3);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--color-text-2);
  text-decoration: none;
  border-radius: var(--r-md);
  transition: color var(--ease-fast), background var(--ease-fast);
  letter-spacing: 0.01em;
}

/* Animated underline */
.navbar__link::after {
  content: '';
  position: absolute;
  bottom: 5px;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: calc(100% - 24px);
  height: 1.5px;
  background: var(--gradient-accent);
  border-radius: var(--r-full);
  transition: transform var(--ease-spring);
  transform-origin: center;
}

.navbar__link:hover {
  color: var(--color-text);
  background: rgba(99, 102, 241, 0.08);
}

.navbar__link:hover::after,
.navbar__link.active::after {
  transform: translateX(-50%) scaleX(1);
}

.navbar__link.active { color: var(--color-text); }

/* Right Controls */
.navbar__controls {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
}

/* Theme Button */
.navbar__theme {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--r-full);
  background: var(--border);
  color: var(--color-text-2);
  font-size: 1rem;
  border: 1px solid var(--border);
  cursor: pointer;
  transition: background var(--ease-fast), color var(--ease-fast), transform var(--ease-spring);
}

.navbar__theme:hover {
  background: rgba(99, 102, 241, 0.12);
  color: var(--color-accent);
  transform: scale(1.1) rotate(20deg);
}

/* Hamburger */
.navbar__hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  cursor: pointer;
  padding: 7px;
  border-radius: var(--r-md);
  background: transparent;
  border: 1px solid var(--border);
  transition: background var(--ease-fast), border-color var(--ease-fast);
}

.navbar__hamburger:hover {
  background: rgba(99, 102, 241, 0.08);
  border-color: var(--border-accent);
}

.navbar__hamburger span {
  display: block;
  width: 100%;
  height: 1.5px;
  background: var(--color-text);
  border-radius: var(--r-full);
  transition: transform var(--ease-base), opacity var(--ease-fast), width var(--ease-base);
  transform-origin: center;
}

.navbar__hamburger.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.navbar__hamburger.open span:nth-child(2) { opacity: 0; width: 0; }
.navbar__hamburger.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* Mobile Menu Drawer */
.navbar__mobile {
  position: fixed;
  top: var(--nav-h);
  left: 0;
  right: 0;
  background: var(--nav-glass-scrolled);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border-bottom: 1px solid var(--border);
  padding: var(--sp-4) var(--sp-5);
  display: flex;
  flex-direction: column;
  gap: var(--sp-1);
  transform: translateY(-8px);
  opacity: 0;
  pointer-events: none;
  transition: transform var(--ease-base), opacity var(--ease-base);
  z-index: calc(var(--z-sticky) - 1);
}

.navbar__mobile.open {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

.navbar__mobile-link {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-3) var(--sp-4);
  border-radius: var(--r-md);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text-2);
  text-decoration: none;
  transition: background var(--ease-fast), color var(--ease-fast);
  border: 1px solid transparent;
}

.navbar__mobile-link:hover,
.navbar__mobile-link.active {
  background: rgba(99, 102, 241, 0.1);
  border-color: var(--border-accent);
  color: var(--color-text);
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background: var(--color-bg-2);
  border-top: 1px solid var(--border);
  padding: var(--sp-16) 0 var(--sp-8);
}

.footer__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--sp-8);
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--sp-12);
  margin-bottom: var(--sp-12);
}

.footer__brand {
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
}

.footer__logo {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 800;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.03em;
}

.footer__desc {
  font-size: 0.88rem;
  color: var(--color-text-2);
  line-height: 1.65;
  max-width: 280px;
}

.footer__social {
  display: flex;
  gap: var(--sp-2);
  flex-wrap: wrap;
}

.footer__social-link {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--r-md);
  background: var(--border);
  color: var(--color-text-2);
  text-decoration: none;
  border: 1px solid var(--border);
  transition: background var(--ease-fast), color var(--ease-fast), transform var(--ease-spring), border-color var(--ease-fast);
}

.footer__social-link:hover {
  background: rgba(99, 102, 241, 0.14);
  color: var(--color-accent);
  border-color: var(--border-accent);
  transform: translateY(-3px);
}

.footer__col-title {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-3);
  margin-bottom: var(--sp-4);
}

.footer__links {
  display: flex;
  flex-direction: column;
  gap: var(--sp-2);
}

.footer__link {
  font-size: 0.88rem;
  color: var(--color-text-2);
  text-decoration: none;
  transition: color var(--ease-fast);
}
.footer__link:hover { color: var(--color-accent); }

.footer__bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--sp-6);
  border-top: 1px solid var(--border);
  gap: var(--sp-4);
  flex-wrap: wrap;
}

.footer__copyright {
  font-size: 0.82rem;
  color: var(--color-text-3);
}

.footer__back-top {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: 0.82rem;
  color: var(--color-text-2);
  cursor: pointer;
  background: none;
  border: none;
  font-family: var(--font-body);
  transition: color var(--ease-fast);
}
.footer__back-top:hover { color: var(--color-accent); }

/* ── Scroll To Top Floating Button ── */
.scroll-top {
  position: fixed;
  bottom: var(--sp-6);
  right: var(--sp-6);
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient-accent);
  color: white;
  border-radius: var(--r-full);
  border: none;
  cursor: pointer;
  font-size: 1.1rem;
  box-shadow: var(--shadow-md);
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
  transition: opacity var(--ease-base), transform var(--ease-spring);
  z-index: var(--z-dropdown);
}

.scroll-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.scroll-top:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-glow);
}

/* ============================================================
   UTILITY COMPONENTS
   ============================================================ */

/* Layout container */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--sp-8);
}

.page-wrapper {
  padding-top: var(--nav-h);
}

/* Sections */
.section {
  padding: var(--sp-24) 0;
}

/* Section Header */
.section-header {
  text-align: center;
  margin-bottom: var(--sp-16);
}

.section-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-accent);
  background: rgba(99, 102, 241, 0.1);
  border: 1px solid rgba(99, 102, 241, 0.2);
  border-radius: var(--r-full);
  padding: 0.28rem var(--sp-4);
  margin-bottom: var(--sp-4);
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(1.75rem, 4vw, 2.6rem);
  font-weight: 800;
  color: var(--color-text);
  letter-spacing: -0.04em;
  line-height: 1.15;
  margin-bottom: var(--sp-4);
}

.section-title span {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-subtitle {
  font-size: 0.98rem;
  color: var(--color-text-2);
  max-width: 520px;
  margin: 0 auto;
  line-height: 1.75;
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  padding: 0.65rem 1.4rem;
  border-radius: var(--r-md);
  font-size: 0.88rem;
  font-weight: 600;
  font-family: var(--font-body);
  text-decoration: none;
  transition: all var(--ease-base);
  position: relative;
  overflow: hidden;
  cursor: pointer;
  border: 1px solid transparent;
  letter-spacing: 0.01em;
  white-space: nowrap;
}

/* Ripple span */
.btn .ripple {
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: scale(0);
  animation: ripple 0.6s linear;
  pointer-events: none;
}

.btn--primary {
  background: var(--gradient-accent);
  color: white;
  box-shadow: 0 4px 20px rgba(99, 102, 241, 0.38);
}
.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(99, 102, 241, 0.5);
}

.btn--outline {
  background: transparent;
  color: var(--color-text);
  border-color: var(--border);
}
.btn--outline:hover {
  border-color: var(--border-accent);
  background: rgba(99, 102, 241, 0.06);
  transform: translateY(-2px);
}

.btn--ghost {
  background: transparent;
  color: var(--color-text-2);
}
.btn--ghost:hover {
  background: rgba(99, 102, 241, 0.08);
  color: var(--color-accent);
}

.btn--sm  { padding: 0.4rem 0.85rem; font-size: 0.78rem; border-radius: var(--r-sm); }
.btn--lg  { padding: 0.8rem 1.9rem;  font-size: 0.95rem; border-radius: var(--r-lg); }
.btn--xl  { padding: 1rem 2.4rem;    font-size: 1rem;    border-radius: var(--r-lg); }

/* ── Badge ── */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-1);
  padding: 0.2rem 0.6rem;
  border-radius: var(--r-full);
  font-size: 0.72rem;
  font-weight: 600;
  background: rgba(99, 102, 241, 0.1);
  color: var(--color-accent);
  border: 1px solid rgba(99, 102, 241, 0.2);
  letter-spacing: 0.01em;
}

.badge--success {
  background: rgba(16, 185, 129, 0.1);
  color: var(--color-success);
  border-color: rgba(16, 185, 129, 0.2);
}
.badge--warning {
  background: rgba(245, 158, 11, 0.1);
  color: var(--color-warning);
  border-color: rgba(245, 158, 11, 0.2);
}
.badge--error {
  background: rgba(244, 63, 94, 0.1);
  color: var(--color-error);
  border-color: rgba(244, 63, 94, 0.2);
}

/* ── Card Base ── */
.card {
  background: var(--color-bg-card);
  border: 1px solid var(--border);
  border-radius: var(--r-xl);
  padding: var(--sp-6);
  transition: border-color var(--ease-base), box-shadow var(--ease-base), transform var(--ease-base);
}
.card:hover {
  border-color: var(--border-accent);
  box-shadow: var(--shadow-glow);
  transform: translateY(-3px);
}

/* ── Gradient Text Utility ── */
.gradient-text {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ── Divider ── */
.divider {
  height: 1px;
  background: var(--border);
  border: none;
  margin: var(--sp-8) 0;
}

/* ── Scroll Reveal Classes (toggled by JS IntersectionObserver) ── */
.reveal {
  opacity: 0.15;
  transform: translateY(12px);
  transition: opacity 0.35s ease, transform 0.35s ease;
}
.reveal.revealed { opacity: 1; transform: translateY(0); }

.reveal-left {
  opacity: 0.15;
  transform: translateX(-12px);
  transition: opacity 0.35s ease, transform 0.35s ease;
}
.reveal-left.revealed { opacity: 1; transform: translateX(0); }

.reveal-right {
  opacity: 0.15;
  transform: translateX(12px);
  transition: opacity 0.35s ease, transform 0.35s ease;
}
.reveal-right.revealed { opacity: 1; transform: translateX(0); }

/* Stagger delays for sibling elements */
.stagger-1 { transition-delay: 0.08s; }
.stagger-2 { transition-delay: 0.16s; }
.stagger-3 { transition-delay: 0.24s; }
.stagger-4 { transition-delay: 0.32s; }
.stagger-5 { transition-delay: 0.40s; }
.stagger-6 { transition-delay: 0.48s; }