/* ═══════════════════════════════════════════════════════════════
   GLOBAL.CSS  –  Design System & CSS Custom Properties
   Jeeva Sivan Portfolio | Dark Futuristic Developer Theme
   ═══════════════════════════════════════════════════════════════ */

/* ─── Google Font Import ─────────────────────────────────────── */
/* Already loaded via <link> in HTML; this is a fallback comment  */

/* ─── CSS Custom Properties (Design Tokens) ─────────────────── */
:root {
  /* ── Colors ── */
  --clr-bg-deep:      #020817;      /* deepest background           */
  --clr-bg-main:      #060d1f;      /* main page background         */
  --clr-bg-surface:   #0a1628;      /* cards, panels                */
  --clr-bg-elevated:  #0f1f3d;      /* elevated / hover states      */
  --clr-bg-glass:     rgba(10, 22, 40, 0.6); /* glassmorphism panels */

  --clr-blue:         #3b82f6;      /* primary accent               */
  --clr-blue-bright:  #60a5fa;      /* light blue                   */
  --clr-blue-dim:     #1d4ed8;      /* dark blue                    */
  --clr-cyan:         #06b6d4;      /* secondary accent             */
  --clr-cyan-bright:  #67e8f9;      /* light cyan                   */
  --clr-purple:       #8b5cf6;      /* tertiary accent              */
  --clr-purple-bright:#a78bfa;      /* light purple                 */
  --clr-indigo:       #6366f1;      /* indigo accent                */

  --clr-text-primary: #e2e8f0;      /* main body text               */
  --clr-text-secondary:#94a3b8;     /* muted text                   */
  --clr-text-muted:   #475569;      /* very muted                   */
  --clr-text-inverse: #020817;      /* text on light bg             */

  --clr-border:       rgba(59, 130, 246, 0.15);
  --clr-border-bright:rgba(59, 130, 246, 0.35);
  --clr-border-cyan:  rgba(6, 182, 212, 0.25);

  /* ── Glow effects ── */
  --glow-blue:  0 0 20px rgba(59, 130, 246, 0.4), 0 0 60px rgba(59, 130, 246, 0.15);
  --glow-cyan:  0 0 20px rgba(6, 182, 212, 0.4),  0 0 60px rgba(6, 182, 212, 0.15);
  --glow-purple:0 0 20px rgba(139, 92, 246, 0.4), 0 0 60px rgba(139, 92, 246, 0.15);
  --glow-text-blue:  0 0 10px rgba(59, 130, 246, 0.8);
  --glow-text-cyan:  0 0 10px rgba(6, 182, 212, 0.8);
  --glow-text-purple:0 0 10px rgba(139, 92, 246, 0.8);

  /* ── Typography ── */
  --font-primary:  'Outfit', system-ui, -apple-system, sans-serif;
  --font-mono:     'JetBrains Mono', 'Fira Code', monospace;

  --fs-xs:   0.75rem;    /* 12px */
  --fs-sm:   0.875rem;   /* 14px */
  --fs-base: 1rem;       /* 16px */
  --fs-md:   1.125rem;   /* 18px */
  --fs-lg:   1.25rem;    /* 20px */
  --fs-xl:   1.5rem;     /* 24px */
  --fs-2xl:  2rem;       /* 32px */
  --fs-3xl:  2.5rem;     /* 40px */
  --fs-4xl:  3rem;       /* 48px */
  --fs-5xl:  3.75rem;    /* 60px */
  --fs-6xl:  4.5rem;     /* 72px */

  --fw-light:   300;
  --fw-normal:  400;
  --fw-medium:  500;
  --fw-semibold:600;
  --fw-bold:    700;
  --fw-extrabold:800;
  --fw-black:   900;

  --lh-tight:  1.15;
  --lh-snug:   1.35;
  --lh-normal: 1.6;
  --lh-relaxed:1.75;

  /* ── Spacing ── */
  --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;
  --sp-32: 8rem;

  /* ── Borders & Radius ── */
  --radius-sm:  4px;
  --radius-md:  8px;
  --radius-lg:  12px;
  --radius-xl:  16px;
  --radius-2xl: 24px;
  --radius-full:9999px;

  /* ── Transitions ── */
  --transition-fast:  150ms ease;
  --transition-base:  250ms ease;
  --transition-slow:  400ms ease;
  --transition-bounce:350ms cubic-bezier(0.34, 1.56, 0.64, 1);

  /* ── Shadows ── */
  --shadow-sm:  0 1px 3px rgba(0,0,0,0.4);
  --shadow-md:  0 4px 16px rgba(0,0,0,0.5);
  --shadow-lg:  0 8px 32px rgba(0,0,0,0.6);
  --shadow-xl:  0 16px 64px rgba(0,0,0,0.7);

  /* ── Layout ── */
  --nav-height:    64px;
  --max-width:     1200px;
  --section-py:    var(--sp-24);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  tab-size: 2;
}

body {
  font-family: var(--font-primary);
  font-size: var(--fs-base);
  font-weight: var(--fw-normal);
  line-height: var(--lh-normal);
  color: var(--clr-text-primary);
  background-color: var(--clr-bg-main);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ─── Typography Base ────────────────────────────────────────── */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-primary);
  font-weight: var(--fw-bold);
  line-height: var(--lh-tight);
  color: var(--clr-text-primary);
}

p {
  line-height: var(--lh-relaxed);
  color: var(--clr-text-secondary);
}

a {
  color: var(--clr-blue-bright);
  text-decoration: none;
  transition: color var(--transition-base);
}

a:hover {
  color: var(--clr-cyan-bright);
}

a:focus-visible {
  outline: 2px solid var(--clr-cyan);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

button {
  font-family: var(--font-primary);
  cursor: pointer;
}

button:focus-visible {
  outline: 2px solid var(--clr-cyan);
  outline-offset: 3px;
}

img, svg, video {
  max-width: 100%;
  display: block;
}

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

.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--sp-6);
}

/* ─── Section Shared Styles ──────────────────────────────────── */
.section {
  min-height: 100vh;
  padding-block: var(--section-py);
  position: relative;
}

.section-content {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--sp-6);
}

/* ─── Section Heading Pattern ────────────────────────────────── */
.section-title {
  font-size: var(--fs-3xl);
  font-weight: var(--fw-extrabold);
  margin-bottom: var(--sp-4);
  position: relative;
  display: inline-block;
}

.section-title .accent {
  background: linear-gradient(135deg, var(--clr-blue-bright), var(--clr-cyan), var(--clr-purple-bright));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-subtitle {
  font-size: var(--fs-md);
  color: var(--clr-text-secondary);
  margin-bottom: var(--sp-12);
  max-width: 600px;
}

.section-divider {
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  margin-bottom: var(--sp-12);
}

.section-divider-line {
  height: 1px;
  flex: 1;
  background: linear-gradient(to right, var(--clr-blue), transparent);
}

.section-divider-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--clr-cyan);
  box-shadow: var(--glow-text-cyan);
}

/* ─── Glassmorphism Card ─────────────────────────────────────── */
.glass-card {
  background: var(--clr-bg-glass);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-xl);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.glass-card:hover {
  border-color: var(--clr-border-bright);
  box-shadow: var(--glow-blue);
}

/* ─── Gradient Text ──────────────────────────────────────────── */
.gradient-text {
  background: linear-gradient(135deg, var(--clr-blue-bright), var(--clr-cyan), var(--clr-purple-bright));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.gradient-text-cyan {
  background: linear-gradient(135deg, var(--clr-cyan), var(--clr-blue-bright));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ─── Glow Borders ───────────────────────────────────────────── */
.border-glow-blue  { border: 1px solid rgba(59, 130, 246, 0.4); }
.border-glow-cyan  { border: 1px solid rgba(6, 182, 212, 0.4); }
.border-glow-purple{ border: 1px solid rgba(139, 92, 246, 0.4); }

/* ─── Tech Badge ─────────────────────────────────────────────── */
.tech-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-1);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  color: var(--clr-cyan-bright);
  background: rgba(6, 182, 212, 0.08);
  border: 1px solid rgba(6, 182, 212, 0.25);
  padding: var(--sp-1) var(--sp-3);
  border-radius: var(--radius-full);
  transition: background var(--transition-fast), border-color var(--transition-fast);
}

.tech-badge:hover {
  background: rgba(6, 182, 212, 0.15);
  border-color: rgba(6, 182, 212, 0.5);
}

/* ─── Buttons ────────────────────────────────────────────────── */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  position: relative;
  font-size: var(--fs-base);
  font-weight: var(--fw-semibold);
  color: #fff;
  background: linear-gradient(135deg, var(--clr-blue-dim), var(--clr-blue));
  border: 1px solid var(--clr-blue);
  padding: var(--sp-3) var(--sp-8);
  border-radius: var(--radius-full);
  overflow: hidden;
  transition: transform var(--transition-bounce), box-shadow var(--transition-base);
}

.btn-primary:hover {
  color: #fff;
  transform: translateY(-2px);
  box-shadow: var(--glow-blue);
}

.btn-primary .btn-glow {
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at center, rgba(96,165,250,0.3), transparent 70%);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.btn-primary:hover .btn-glow { opacity: 1; }

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: var(--fs-base);
  font-weight: var(--fw-semibold);
  color: var(--clr-cyan-bright);
  background: transparent;
  border: 1px solid rgba(6, 182, 212, 0.4);
  padding: var(--sp-3) var(--sp-8);
  border-radius: var(--radius-full);
  transition: transform var(--transition-bounce), box-shadow var(--transition-base), background var(--transition-base), border-color var(--transition-base);
}

.btn-secondary:hover {
  color: var(--clr-cyan-bright);
  background: rgba(6, 182, 212, 0.08);
  border-color: var(--clr-cyan);
  transform: translateY(-2px);
  box-shadow: var(--glow-cyan);
}

/* ─── Placeholder (dev helper) ───────────────────────────────── */
.placeholder-block {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 50vh;
  gap: var(--sp-4);
  border: 2px dashed var(--clr-border-bright);
  border-radius: var(--radius-2xl);
  padding: var(--sp-12);
  text-align: center;
  opacity: 0.6;
}

.placeholder-icon {
  font-size: 3rem;
  line-height: 1;
}

.placeholder-block h2 {
  font-size: var(--fs-2xl);
  background: linear-gradient(135deg, var(--clr-blue-bright), var(--clr-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.placeholder-block p {
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
}

/* ─── Scroll Animations (observer-based) ────────────────────── */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-left {
  opacity: 0;
  transform: translateX(-30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal-left.visible {
  opacity: 1;
  transform: translateX(0);
}

.reveal-right {
  opacity: 0;
  transform: translateX(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal-right.visible {
  opacity: 1;
  transform: translateX(0);
}

/* ─── Scrollbar ──────────────────────────────────────────────── */
::-webkit-scrollbar               { width: 6px; }
::-webkit-scrollbar-track         { background: var(--clr-bg-deep); }
::-webkit-scrollbar-thumb         { background: var(--clr-blue-dim); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover   { background: var(--clr-blue); }

/* ─── Selection ──────────────────────────────────────────────── */
::selection {
  background: rgba(59, 130, 246, 0.35);
  color: #fff;
}

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

/* ─── Responsive Breakpoints ─────────────────────────────────── */
/* mobile-first — overrides go in the component CSS files         */
/* xs: < 480px | sm: 480px+ | md: 768px+ | lg: 1024px+ | xl: 1280px+ */