/* ============================================================
   GLOBAL CSS — Design Tokens, Reset, Typography, Utilities
   AI/ML Portfolio — Serhan Emre Telatar
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=Space+Grotesk:wght@400;500;600;700&display=swap');

/* ─── CSS Variables ─────────────────────────────────────── */
:root {
  /* Colors */
  --bg-primary:    #070711;
  --bg-secondary:  #0e0e22;
  --bg-card:       rgba(255, 255, 255, 0.04);
  --bg-card-hover: rgba(255, 255, 255, 0.08);

  --violet:        #7c3aed;
  --violet-light:  #a855f7;
  --violet-glow:   rgba(124, 58, 237, 0.4);
  --cyan:          #06b6d4;
  --cyan-glow:     rgba(6, 182, 212, 0.4);
  --pink:          #ec4899;

  --text-primary:   #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted:     #475569;

  --border:         rgba(255, 255, 255, 0.08);
  --border-glow:    rgba(124, 58, 237, 0.5);

  /* Typography */
  --font-body:    'Inter', sans-serif;
  --font-heading: 'Space Grotesk', sans-serif;

  /* Spacing */
  --max-width: 1200px;
  --section-px: clamp(1rem, 5vw, 4rem);
  --section-py: 6rem;

  /* Radius */
  --radius-sm:  0.5rem;
  --radius-md:  1rem;
  --radius-lg:  1.5rem;
  --radius-xl:  2rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);

  /* Shadows */
  --shadow-violet: 0 0 30px rgba(124, 58, 237, 0.3);
  --shadow-cyan:   0 0 30px rgba(6, 182, 212, 0.3);
  --shadow-card:   0 8px 32px rgba(0, 0, 0, 0.4);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
  min-height: 100vh;
}

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

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

ul, ol {
  list-style: none;
}

button {
  cursor: pointer;
  font-family: var(--font-body);
  border: none;
  background: none;
}

input, textarea, select {
  font-family: var(--font-body);
}

/* ─── Scrollbar ─────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--violet); border-radius: var(--radius-full); }
::-webkit-scrollbar-thumb:hover { background: var(--violet-light); }

/* ─── Typography ─────────────────────────────────────────── */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-primary);
}

/* ─── Section Layout ─────────────────────────────────────── */
.section {
  padding: var(--section-py) var(--section-px);
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 1rem;
}
.section-tag::before {
  content: '';
  display: inline-block;
  width: 20px;
  height: 2px;
  background: var(--cyan);
  border-radius: 2px;
}

.section-title {
  font-size: clamp(2rem, 5vw, 3.5rem);
  background: linear-gradient(135deg, var(--text-primary) 40%, var(--violet-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 1rem;
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 600px;
}

.section-header {
  text-align: center;
  margin-bottom: 4rem;
}
.section-header .section-tag {
  justify-content: center;
}
.section-header .section-subtitle {
  margin: 0 auto;
}

/* ─── Glassmorphism Card ──────────────────────────────────── */
.glass-card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  transition: var(--transition);
}
.glass-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-glow);
  box-shadow: var(--shadow-violet);
  transform: translateY(-4px);
}

/* ─── Buttons ─────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.95rem;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: linear-gradient(135deg, var(--violet), var(--cyan));
  color: #fff;
  box-shadow: 0 4px 20px var(--violet-glow);
}
.btn-primary:hover {
  box-shadow: 0 8px 30px var(--violet-glow);
  transform: translateY(-2px);
}

.btn-outline {
  border: 1px solid var(--border-glow);
  color: var(--violet-light);
  background: transparent;
}
.btn-outline:hover {
  background: var(--violet-glow);
  border-color: var(--violet-light);
  transform: translateY(-2px);
}

.btn-ghost {
  color: var(--text-secondary);
  padding: 0.5rem 1rem;
}
.btn-ghost:hover {
  color: var(--text-primary);
}

/* Disabled state */
.btn[disabled], .btn.disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}

/* ─── Tags & Badges ───────────────────────────────────────── */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  font-size: 0.78rem;
  font-weight: 600;
  transition: var(--transition);
}
.tag-violet { background: rgba(124,58,237,0.15); color: var(--violet-light); border: 1px solid rgba(124,58,237,0.3); }
.tag-cyan   { background: rgba(6,182,212,0.12); color: var(--cyan); border: 1px solid rgba(6,182,212,0.3); }
.tag-pink   { background: rgba(236,72,153,0.12); color: var(--pink); border: 1px solid rgba(236,72,153,0.3); }
.tag-green  { background: rgba(34,197,94,0.12); color: #22c55e; border: 1px solid rgba(34,197,94,0.3); }
.tag-orange { background: rgba(249,115,22,0.12); color: #f97316; border: 1px solid rgba(249,115,22,0.3); }
.tag-yellow { background: rgba(234,179,8,0.12); color: #eab308; border: 1px solid rgba(234,179,8,0.3); }

/* Status badges */
.badge-completed  { background: rgba(34,197,94,0.15); color: #4ade80; border: 1px solid rgba(34,197,94,0.3); font-size: 0.72rem; font-weight:600; padding: 0.2rem 0.6rem; border-radius: var(--radius-full); }
.badge-progress   { background: rgba(249,115,22,0.15); color: #fb923c; border: 1px solid rgba(249,115,22,0.3); font-size: 0.72rem; font-weight:600; padding: 0.2rem 0.6rem; border-radius: var(--radius-full); }

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

/* ─── Glow Line ───────────────────────────────────────────── */
.glow-line {
  width: 80px;
  height: 3px;
  background: linear-gradient(90deg, var(--violet), var(--cyan));
  border-radius: var(--radius-full);
  margin: 1rem auto;
}

/* ─── Grid Layouts ─────────────────────────────────────────── */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 2rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; }

/* ─── Stars ───────────────────────────────────────────────── */
.stars {
  display: inline-flex;
  gap: 2px;
  color: #facc15;
  font-size: 1rem;
}

/* ─── AOS (Animate on Scroll) overrides ───────────────────── */
[data-aos] { opacity: 0; transition-property: opacity, transform; }
[data-aos].aos-animate { opacity: 1; }

/* ─── Responsive ──────────────────────────────────────────── */
@media (max-width: 1024px) {
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  :root { --section-py: 4rem; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}
@media (max-width: 480px) {
  :root { --section-py: 3rem; }
}