/* =========================================================
   styles.css – Subrata Bhunia Portfolio
   ========================================================= */

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

:root {
  --clr-bg:        #0d1117;
  --clr-bg-alt:    #161b22;
  --clr-surface:   #1c2333;
  --clr-border:    #30363d;
  --clr-accent:    #58a6ff;
  --clr-accent2:   #7ee787;
  --clr-text:      #e6edf3;
  --clr-muted:     #8b949e;
  --clr-heading:   #f0f6fc;
  --radius:        12px;
  --radius-sm:     6px;
  --shadow:        0 8px 30px rgba(0,0,0,.4);
  --shadow-card:   0 2px 12px rgba(0,0,0,.3);
  --transition:    .25s ease;
  --max-w:         1100px;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--clr-bg);
  color: var(--clr-text);
  line-height: 1.7;
  font-size: 16px;
}

a { color: var(--clr-accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: #79b8ff; }

ul { list-style: none; }

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

/* ----- Utility ----- */
.container {
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: clamp(1rem, 5vw, 2rem);
}

.accent { color: var(--clr-accent); }

.mt-1 { margin-top: 1.5rem; }

.section {
  padding-block: clamp(4rem, 8vw, 7rem);
}

.section-alt {
  background: var(--clr-bg-alt);
}

.section-title {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  font-weight: 700;
  color: var(--clr-heading);
  margin-bottom: 3rem;
  position: relative;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--clr-accent);
  border-radius: 2px;
  margin-top: .6rem;
}

/* ----- Buttons ----- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .65rem 1.4rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: .9rem;
  cursor: pointer;
  transition: all var(--transition);
  border: 2px solid transparent;
  text-decoration: none;
}

.btn-primary {
  background: var(--clr-accent);
  color: #0d1117;
  border-color: var(--clr-accent);
}
.btn-primary:hover {
  background: #79b8ff;
  border-color: #79b8ff;
  color: #0d1117;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(88,166,255,.3);
}

.btn-outline {
  background: transparent;
  color: var(--clr-accent);
  border-color: var(--clr-accent);
}
.btn-outline:hover {
  background: var(--clr-accent);
  color: #0d1117;
  transform: translateY(-2px);
}

.btn-sm { padding: .4rem 1rem; font-size: .85rem; }

.btn-full { width: 100%; justify-content: center; }

/* ----- NAV ----- */
.nav-header {
  position: fixed;
  top: 0;
  inset-inline: 0;
  z-index: 100;
  background: rgba(13,17,23,.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.nav-header.scrolled {
  border-bottom-color: var(--clr-border);
  box-shadow: 0 2px 20px rgba(0,0,0,.4);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  font-weight: 800;
  font-size: 1.3rem;
  color: var(--clr-heading);
  background: var(--clr-accent);
  color: #0d1117;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  letter-spacing: -.02em;
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-links li a {
  color: var(--clr-muted);
  font-size: .9rem;
  font-weight: 500;
  transition: color var(--transition);
}

.nav-links li a:hover { color: var(--clr-text); }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--clr-text);
  border-radius: 2px;
  transition: all var(--transition);
}

.nav-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ----- HERO ----- */
.hero {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding-top: 64px;
  position: relative;
  background:
    radial-gradient(ellipse 80% 60% at 50% -10%, rgba(88,166,255,.12) 0%, transparent 70%),
    var(--clr-bg);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 3rem;
  align-items: center;
  width: 100%;
  padding-block: 4rem;
}

.hero-greeting {
  color: var(--clr-accent);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  margin-bottom: .5rem;
}

.hero-name {
  font-size: clamp(2.8rem, 7vw, 5rem);
  font-weight: 800;
  color: var(--clr-heading);
  line-height: 1.1;
  margin-bottom: .5rem;
}

.hero-title {
  font-size: clamp(1rem, 2.5vw, 1.4rem);
  font-weight: 400;
  color: var(--clr-muted);
  margin-bottom: 1.5rem;
}

.hero-desc {
  max-width: 520px;
  color: var(--clr-muted);
  margin-bottom: 2rem;
  font-size: 1.05rem;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}

.hero-social {
  display: flex;
  gap: 1.2rem;
}

.hero-social a {
  color: var(--clr-muted);
  transition: color var(--transition), transform var(--transition);
}

.hero-social a:hover {
  color: var(--clr-accent);
  transform: translateY(-3px);
}

/* Avatar */
.hero-avatar {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  flex-shrink: 0;
}

.avatar-ring {
  width: clamp(160px, 20vw, 220px);
  height: clamp(160px, 20vw, 220px);
  border-radius: 50%;
  border: 3px solid var(--clr-accent);
  box-shadow: 0 0 40px rgba(88,166,255,.25);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--clr-surface);
  position: relative;
}

.avatar-ring::before {
  content: '';
  position: absolute;
  inset: -6px;
  border-radius: 50%;
  border: 1px solid rgba(88,166,255,.2);
}

.avatar-initials {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  color: var(--clr-accent);
  letter-spacing: -.04em;
}

.avatar-badge {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: 999px;
  padding: .35rem .9rem;
  font-size: .8rem;
  color: var(--clr-muted);
}

.badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--clr-accent2);
  box-shadow: 0 0 6px var(--clr-accent2);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: .4; }
}

/* Scroll hint */
.hero-scroll {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  animation: bounce 2s infinite;
}

.hero-scroll a { color: var(--clr-muted); }
.hero-scroll a:hover { color: var(--clr-accent); }

@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

/* ----- ABOUT ----- */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
}

.about-text p {
  color: var(--clr-muted);
  margin-bottom: 1rem;
  font-size: 1.02rem;
}

.about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.stat-card {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  text-align: center;
}

.stat-number {
  display: block;
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--clr-accent);
  line-height: 1;
  margin-bottom: .4rem;
}

.stat-label {
  font-size: .8rem;
  color: var(--clr-muted);
  font-weight: 500;
}

/* ----- SKILLS ----- */
.skills-categories {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 2rem;
}

.skill-group-title {
  font-size: .95rem;
  font-weight: 700;
  color: var(--clr-heading);
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: .08em;
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
}

.tag {
  display: inline-block;
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  color: var(--clr-text);
  border-radius: var(--radius-sm);
  padding: .3rem .75rem;
  font-size: .85rem;
  font-weight: 500;
  transition: background var(--transition), border-color var(--transition), color var(--transition);
}

.tag:hover {
  background: rgba(88,166,255,.15);
  border-color: var(--clr-accent);
  color: var(--clr-accent);
}

.tag-sm {
  font-size: .75rem;
  padding: .2rem .6rem;
}

/* ----- EXPERIENCE ----- */
.timeline {
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: .5rem;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--clr-border);
  border-radius: 2px;
}

.timeline-item {
  position: relative;
  margin-bottom: 2.5rem;
}

.timeline-item:last-child { margin-bottom: 0; }

.timeline-dot {
  position: absolute;
  left: -2rem;
  top: .35rem;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--clr-accent);
  border: 3px solid var(--clr-bg);
  box-shadow: 0 0 0 2px var(--clr-accent);
}

.timeline-content {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.timeline-content:hover {
  border-color: var(--clr-accent);
  box-shadow: 0 0 0 1px rgba(88,166,255,.2), var(--shadow-card);
}

.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: .5rem;
  margin-bottom: .25rem;
}

.timeline-role {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--clr-heading);
}

.timeline-period {
  font-size: .82rem;
  color: var(--clr-accent);
  font-weight: 600;
  background: rgba(88,166,255,.1);
  padding: .2rem .6rem;
  border-radius: var(--radius-sm);
  white-space: nowrap;
}

.timeline-company {
  color: var(--clr-muted);
  font-size: .9rem;
  font-weight: 500;
  margin-bottom: 1rem;
}

.timeline-bullets {
  list-style: disc;
  padding-left: 1.2rem;
  color: var(--clr-muted);
  font-size: .9rem;
}

.timeline-bullets li { margin-bottom: .4rem; }

/* ----- PROJECTS ----- */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}

.project-card {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: .75rem;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.project-card:hover {
  transform: translateY(-4px);
  border-color: var(--clr-accent);
  box-shadow: 0 12px 40px rgba(0,0,0,.4), 0 0 0 1px rgba(88,166,255,.2);
}

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
}

.project-icon { color: var(--clr-accent); }

.project-links { display: flex; gap: .75rem; }

.project-links a {
  color: var(--clr-muted);
  transition: color var(--transition);
}

.project-links a:hover { color: var(--clr-accent); }

.project-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--clr-heading);
}

.project-desc {
  color: var(--clr-muted);
  font-size: .9rem;
  flex: 1;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
  margin-top: auto;
}

/* ----- CONTACT ----- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: 3rem;
  align-items: start;
}

.contact-intro {
  color: var(--clr-muted);
  margin-bottom: 2rem;
  font-size: 1.02rem;
}

.contact-items {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: .75rem;
  color: var(--clr-muted);
  font-size: .95rem;
  font-weight: 500;
  transition: color var(--transition);
}

.contact-item:hover { color: var(--clr-accent); }

.contact-item-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

/* Form */
.contact-form {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: .4rem;
}

.form-group label {
  font-size: .85rem;
  font-weight: 600;
  color: var(--clr-text);
  letter-spacing: .02em;
}

.form-group input,
.form-group textarea {
  background: var(--clr-bg);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-sm);
  padding: .7rem 1rem;
  color: var(--clr-text);
  font-family: inherit;
  font-size: .95rem;
  transition: border-color var(--transition), box-shadow var(--transition);
  outline: none;
  resize: vertical;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--clr-muted);
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--clr-accent);
  box-shadow: 0 0 0 3px rgba(88,166,255,.15);
}

.form-success {
  color: var(--clr-accent2);
  font-size: .9rem;
  text-align: center;
  font-weight: 600;
}

/* ----- FOOTER ----- */
.footer {
  background: var(--clr-bg-alt);
  border-top: 1px solid var(--clr-border);
  padding-block: 1.5rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: .5rem;
  font-size: .85rem;
  color: var(--clr-muted);
}

.footer-copy { color: var(--clr-muted); }

/* ----- ANIMATIONS ----- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .6s ease, transform .6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: none;
}

/* ----- RESPONSIVE ----- */
@media (max-width: 900px) {
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-text { order: 2; }
  .hero-avatar { order: 1; }

  .hero-desc { margin-inline: auto; }
  .hero-cta { justify-content: center; }
  .hero-social { justify-content: center; }

  .about-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .nav-links {
    position: fixed;
    inset: 64px 0 0;
    background: var(--clr-bg);
    flex-direction: column;
    justify-content: flex-start;
    padding: 2rem;
    gap: 1.5rem;
    transform: translateX(100%);
    transition: transform var(--transition);
    border-top: 1px solid var(--clr-border);
    z-index: 99;
  }

  .nav-links.nav-open { transform: none; }

  .nav-links li a {
    font-size: 1.1rem;
    color: var(--clr-text);
  }

  .nav-toggle { display: flex; }

  .about-stats { grid-template-columns: 1fr 1fr; }

  .projects-grid { grid-template-columns: 1fr; }

  .timeline { padding-left: 1.5rem; }

  .timeline-header { flex-direction: column; }

  .footer-inner { flex-direction: column; text-align: center; }
}