/* ==========================================================================
   Prahlad Kumar Shah — Portfolio Stylesheet
   ========================================================================== */

:root{
  /* Dark theme (default) */
  --bg: #0a0e17;
  --bg-alt: #0d1320;
  --surface: #111827;
  --surface-2: #161f31;
  --text: #e6edf3;
  --text-muted: #8b96a8;
  --border: rgba(255,255,255,0.08);

  --accent: #64ffda;        /* cyan/teal */
  --accent-2: #a855f7;      /* purple */
  --accent-3: #39ff14;      /* matrix green */
  --accent-warm: #ff6ec7;   /* pink, used sparingly */

  --gradient: linear-gradient(135deg, var(--accent) 0%, var(--accent-2) 100%);
  --shadow: 0 10px 30px rgba(0,0,0,0.45);
  --radius: 16px;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --font-body: 'Poppins', 'Segoe UI', sans-serif;
  --transition: all 0.3s cubic-bezier(.4,0,.2,1);
}

[data-theme="light"]{
  --bg: #f4f6fb;
  --bg-alt: #ffffff;
  --surface: #ffffff;
  --surface-2: #eef1f8;
  --text: #10151f;
  --text-muted: #566078;
  --border: rgba(10,14,23,0.08);
  --shadow: 0 10px 30px rgba(20,30,60,0.12);
}

*{ margin:0; padding:0; box-sizing:border-box; }

html{ scroll-behavior:smooth; }

body{
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  line-height: 1.6;
  overflow-x: hidden;
  transition: background .4s ease, color .4s ease;
}

.container{
  width: 100%;
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 24px;
}

a{ text-decoration:none; color:inherit; }
ul{ list-style:none; }
img{ max-width:100%; display:block; }
button{ font-family:inherit; cursor:pointer; border:none; background:none; }

::selection{ background: var(--accent); color:#000; }

/* Scrollbar */
::-webkit-scrollbar{ width:10px; }
::-webkit-scrollbar-track{ background: var(--bg); }
::-webkit-scrollbar-thumb{ background: var(--accent-2); border-radius:10px; }

/* ===== Background canvas ===== */
#star-canvas{
  position: fixed;
  inset: 0;
  z-index: -2;
  background: radial-gradient(ellipse at top, var(--bg-alt), var(--bg) 70%);
}

.cursor-glow{
  position: fixed;
  width: 260px; height: 260px;
  border-radius: 50%;
  pointer-events: none;
  background: radial-gradient(circle, rgba(100,255,218,0.10), transparent 70%);
  z-index: 0;
  transform: translate(-50%,-50%);
  transition: opacity .3s ease;
  display: none;
}
@media (min-width: 900px){ .cursor-glow{ display:block; } }

/* ===== Loader ===== */
.loader{
  position: fixed; inset: 0;
  background: var(--bg);
  z-index: 9999;
  display:flex; align-items:center; justify-content:center;
  transition: opacity .5s ease, visibility .5s ease;
}
.loader.hide{ opacity:0; visibility:hidden; }
.loader-text{
  font-family: var(--font-mono);
  color: var(--accent);
  font-size: 1.1rem;
  letter-spacing: .5px;
}
.cursor-blink{ animation: blink 1s infinite; }
@keyframes blink{ 50%{ opacity:0; } }

/* ===== Header ===== */
.site-header{
  position: fixed;
  top:0; left:0; right:0;
  z-index: 100;
  padding: 18px 0;
  transition: var(--transition);
  background: transparent;
}
.site-header.scrolled{
  background: rgba(10,14,23,0.75);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
  padding: 12px 0;
}
[data-theme="light"] .site-header.scrolled{ background: rgba(244,246,251,0.85); }

.navbar{ display:flex; align-items:center; justify-content:space-between; }

.logo{
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.3rem;
  color: var(--text);
}
.logo-bracket{ color: var(--accent); }

.nav-links{ display:flex; gap: 32px; }
.nav-link{
  font-size: .95rem;
  font-weight: 500;
  color: var(--text-muted);
  position: relative;
  padding: 4px 0;
  transition: var(--transition);
}
.nav-link::after{
  content:'';
  position:absolute; left:0; bottom:-2px;
  width:0; height:2px;
  background: var(--gradient);
  transition: width .3s ease;
}
.nav-link:hover, .nav-link.active{ color: var(--text); }
.nav-link:hover::after, .nav-link.active::after{ width:100%; }

.nav-actions{ display:flex; align-items:center; gap:14px; }
.theme-toggle{
  width:38px; height:38px;
  border-radius:50%;
  border:1px solid var(--border);
  color: var(--text);
  display:flex; align-items:center; justify-content:center;
  transition: var(--transition);
}
.theme-toggle:hover{ border-color: var(--accent); color: var(--accent); transform: rotate(20deg); }

.hamburger{ display:none; flex-direction:column; gap:5px; width:28px; }
.hamburger span{ height:2px; width:100%; background: var(--text); border-radius:2px; transition: var(--transition); }

/* ===== Buttons ===== */
.btn{
  display:inline-flex; align-items:center; gap:10px;
  padding: 13px 26px;
  border-radius: 50px;
  font-weight: 600;
  font-size: .95rem;
  transition: var(--transition);
}
.btn-primary{
  background: var(--gradient);
  color: #061019;
  box-shadow: 0 8px 24px rgba(100,255,218,0.25);
}
.btn-primary:hover{ transform: translateY(-3px); box-shadow: 0 12px 30px rgba(100,255,218,0.4); }
.btn-outline{
  border: 1.5px solid var(--accent-2);
  color: var(--text);
}
.btn-outline:hover{ background: var(--accent-2); color:#fff; transform: translateY(-3px); }

/* ===== Hero ===== */
.hero{
  position: relative;
  min-height: 100vh;
  display:flex; align-items:center;
  padding-top: 90px;
  overflow: hidden;
}
#matrix-canvas{
  position:absolute; inset:0;
  opacity:.16;
  z-index:0;
  pointer-events:none;
}
.hero-content{
  position: relative; z-index:1;
  display:grid;
  grid-template-columns: 1.3fr 1fr;
  align-items:center;
  gap: 40px;
}
.hero-pre{
  font-family: var(--font-mono);
  color: var(--accent);
  margin-bottom: 10px;
  font-size: .95rem;
}
.prompt{ color: var(--accent-2); margin-right:6px; }

.hero-name{
  font-size: clamp(2.2rem, 5vw, 3.6rem);
  font-weight: 800;
  line-height:1.1;
  background: var(--gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 12px;
}
.hero-role{
  font-family: var(--font-mono);
  font-size: clamp(1.1rem, 2.2vw, 1.5rem);
  color: var(--text);
  min-height: 2em;
  margin-bottom: 18px;
}
.type-cursor{ color: var(--accent); animation: blink 1s infinite; }

.hero-tagline{
  color: var(--text-muted);
  max-width: 560px;
  margin-bottom: 28px;
}

.hero-stats{
  display:flex; flex-wrap:wrap; gap: 28px;
  margin-bottom: 30px;
}
.stat{ display:flex; flex-direction:column; }
.stat-num, .stat-inf{
  font-family: var(--font-mono);
  font-size: 1.7rem;
  font-weight:700;
  color: var(--accent);
}
.stat-label{ font-size: .78rem; color: var(--text-muted); text-transform: uppercase; letter-spacing:.5px; }

.hero-buttons{ display:flex; flex-wrap:wrap; gap:16px; margin-bottom: 28px; }

.hero-socials{ display:flex; gap:16px; }
.hero-socials a{
  width:42px; height:42px;
  border-radius:50%;
  border: 1px solid var(--border);
  display:flex; align-items:center; justify-content:center;
  transition: var(--transition);
}
.hero-socials a:hover{ background: var(--accent); color:#061019; transform: translateY(-4px); border-color: var(--accent); }

.hero-photo{ position:relative; display:flex; flex-direction:column; align-items:center; }
.photo-ring{
  width: min(320px, 80vw);
  aspect-ratio: 1/1;
  border-radius: 50%;
  padding: 6px;
  background: conic-gradient(from 0deg, var(--accent), var(--accent-2), var(--accent-warm), var(--accent));
  animation: spin 8s linear infinite;
  box-shadow: var(--shadow);
}
.photo-ring img{
  width:100%; height:100%;
  border-radius:50%;
  object-fit: cover;
  border: 5px solid var(--bg);
  animation: spin-reverse 8s linear infinite;
  background: var(--surface);
}
@keyframes spin{ to{ transform: rotate(360deg); } }
@keyframes spin-reverse{ to{ transform: rotate(-360deg); } }

.badge-available{
  margin-top: 18px;
  font-family: var(--font-mono);
  font-size: .8rem;
  color: var(--text-muted);
  display:flex; align-items:center; gap:8px;
}
.badge-available i{ color: var(--accent-3); font-size:.6rem; animation: pulse 1.6s infinite; }
@keyframes pulse{ 0%,100%{ opacity:1; } 50%{ opacity:.3; } }

.scroll-down{
  position:absolute; bottom: 30px; left:50%; transform: translateX(-50%);
  color: var(--text-muted);
  animation: bounce 2s infinite;
  z-index:1;
}
@keyframes bounce{ 0%,100%{ transform: translate(-50%,0); } 50%{ transform: translate(-50%,10px); } }

/* ===== Sections ===== */
.section{ padding: 110px 0; position: relative; z-index:1; }
.section-alt{ background: var(--surface); border-top:1px solid var(--border); border-bottom:1px solid var(--border); }

.section-kicker{
  font-family: var(--font-mono);
  color: var(--accent);
  font-size: .9rem;
  margin-bottom: 10px;
}
.section-title{
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 700;
  margin-bottom: 16px;
}
.section-sub{ color: var(--text-muted); max-width: 620px; margin-bottom: 50px; }

/* Reveal animation */
.reveal{ opacity:0; transform: translateY(40px); transition: opacity .7s ease, transform .7s ease; }
.reveal.visible{ opacity:1; transform: translateY(0); }

/* ===== About ===== */
.about-grid{ display:grid; grid-template-columns: 1fr 1.2fr; gap: 50px; align-items:start; margin-top: 40px; }
.about-text p{ color: var(--text-muted); margin-bottom: 18px; }

.strengths{ display:grid; gap: 20px; }
.strength-card{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: var(--transition);
}
.strength-card:hover{ transform: translateY(-6px); border-color: var(--accent); box-shadow: var(--shadow); }
.strength-icon{
  width:48px; height:48px;
  border-radius: 12px;
  background: var(--gradient);
  color:#061019;
  display:flex; align-items:center; justify-content:center;
  font-size:1.2rem;
  margin-bottom: 14px;
}
.strength-card h3{ margin-bottom:8px; }
.strength-card p{ color: var(--text-muted); font-size: .92rem; }

/* ===== Skills ===== */
.skills-grid{ display:grid; grid-template-columns: repeat(2,1fr); gap: 30px; margin-top: 40px; }
.skill-category{
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
}
.skill-category h3{ margin-bottom: 18px; display:flex; align-items:center; gap:10px; color: var(--accent); font-size: 1.05rem; }
.skill-chips{ display:flex; flex-wrap:wrap; gap: 10px; }
.chip{
  display:inline-flex; align-items:center; gap:8px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 8px 14px;
  border-radius: 50px;
  font-size: .85rem;
  transition: var(--transition);
}
.chip:hover{ transform: translateY(-3px) scale(1.05); border-color: var(--accent-2); box-shadow: 0 6px 16px rgba(168,85,247,0.25); }

.languages{ margin-top: 50px; }
.languages h3{ margin-bottom: 20px; display:flex; align-items:center; gap:10px; color: var(--accent); }
.lang-bars{ display:grid; gap: 18px; max-width: 500px; }
.lang-bar span{ display:block; margin-bottom:6px; font-size:.9rem; font-weight:500; }
.bar{ height: 8px; background: var(--surface-2); border-radius: 10px; overflow:hidden; }
.bar-fill{
  height:100%; width:0%;
  background: var(--gradient);
  border-radius: 10px;
  transition: width 1.4s cubic-bezier(.4,0,.2,1);
}

/* ===== Timeline ===== */
.timeline{ position:relative; margin-top: 40px; }
.timeline::before{
  content:'';
  position:absolute; left: 21px; top:0; bottom:0;
  width: 2px;
  background: linear-gradient(var(--accent), var(--accent-2));
  opacity:.4;
}
.timeline-item{ position:relative; padding-left: 60px; margin-bottom: 34px; }
.timeline-dot{
  position:absolute; left: 12px; top: 6px;
  width: 20px; height:20px;
  border-radius:50%;
  background: var(--bg);
  border: 3px solid var(--accent);
  box-shadow: 0 0 0 4px rgba(100,255,218,0.15);
}
.timeline-card{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
  transition: var(--transition);
}
.timeline-card:hover{ border-color: var(--accent-2); transform: translateX(6px); }
.exp-index{ font-family: var(--font-mono); color: var(--accent-2); font-size:.8rem; }
.timeline-card h3{ margin: 6px 0; font-size: 1.2rem; }
.exp-company{ color: var(--accent); font-size: .9rem; margin-bottom: 10px; display:flex; align-items:center; gap:8px; }
.exp-desc{ color: var(--text-muted); margin-bottom: 12px; font-size:.92rem; }

.exp-details summary{
  cursor:pointer;
  font-family: var(--font-mono);
  font-size: .82rem;
  color: var(--accent-2);
  outline:none;
  list-style: none;
  display:flex; align-items:center; gap:6px;
}
.exp-details summary::-webkit-details-marker{ display:none; }
.exp-details summary::before{ content:'▶'; font-size:.65rem; transition: transform .25s ease; }
.exp-details[open] summary::before{ transform: rotate(90deg); }
.exp-details ul{ margin-top: 14px; padding-left: 18px; display:grid; gap:8px; }
.exp-details li{ font-size: .88rem; color: var(--text-muted); list-style: disc; }

/* ===== Education ===== */
.edu-grid{ display:grid; grid-template-columns: 1fr 1fr; gap: 40px; margin-top: 40px; }
.edu-cards{ display:grid; gap: 20px; }
.edu-card{
  display:flex; gap:18px; align-items:flex-start;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
  transition: var(--transition);
}
.edu-card:hover{ border-color: var(--accent); }
.edu-card i{ font-size: 1.6rem; color: var(--accent); margin-top:4px; }
.edu-card h3{ font-size: 1.05rem; margin-bottom: 4px; }
.edu-card p{ color: var(--text-muted); font-size: .88rem; }
.edu-year{ font-family: var(--font-mono); font-size: .78rem; color: var(--accent-2); }

.cert-grid{ display:grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.cert-card{
  display:flex; align-items:center; gap: 12px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  font-size: .85rem;
  transition: var(--transition);
}
.cert-card:hover{ transform: translateY(-4px); border-color: var(--accent-2); }
.cert-card i{ color: var(--accent-2); font-size: 1.1rem; }

/* ===== Hobbies ===== */
.hobby-grid{ display:grid; grid-template-columns: repeat(4,1fr); gap: 26px; margin-top: 10px; }
.hobby-card{ perspective: 1200px; height: 200px; }
.hobby-inner{
  position:relative; width:100%; height:100%;
  transform-style: preserve-3d;
  transition: transform .7s cubic-bezier(.4,0,.2,1);
}
.hobby-card:hover .hobby-inner{ transform: rotateY(180deg); }
.hobby-front, .hobby-back{
  position:absolute; inset:0;
  backface-visibility: hidden;
  border-radius: var(--radius);
  display:flex; flex-direction:column; align-items:center; justify-content:center;
  text-align:center;
  padding: 20px;
  border: 1px solid var(--border);
}
.hobby-front{ background: var(--surface); }
.hobby-front i{ font-size: 2.4rem; color: var(--accent); margin-bottom: 14px; }
.hobby-front h3{ font-size: 1.05rem; }
.hobby-back{
  background: var(--gradient);
  color: #061019;
  transform: rotateY(180deg);
  font-weight: 500;
  font-size: .88rem;
}

/* ===== Contact ===== */
.contact-grid{ display:grid; grid-template-columns: .8fr 1.2fr; gap: 50px; margin-top: 10px; }
.contact-info{ display:grid; gap: 16px; align-content:start; }
.contact-item{
  display:flex; align-items:center; gap: 16px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  transition: var(--transition);
}
.contact-item:hover{ border-color: var(--accent); transform: translateX(6px); }
.contact-item i{ font-size: 1.3rem; color: var(--accent); width: 30px; text-align:center; }
.contact-item span{ display:block; font-size: .75rem; color: var(--text-muted); text-transform:uppercase; letter-spacing:.5px; }
.contact-item p{ font-weight: 500; }

.contact-form{ display:grid; gap: 16px; }
.form-row{ display:grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.contact-form input, .contact-form textarea{
  width:100%;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px 16px;
  color: var(--text);
  font-family: inherit;
  transition: var(--transition);
  resize: vertical;
}
.contact-form input:focus, .contact-form textarea:focus{ outline:none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(100,255,218,0.15); }
.form-note{ font-size: .78rem; color: var(--text-muted); }

/* ===== Footer ===== */
.site-footer{ background: var(--bg-alt); border-top: 1px solid var(--border); padding: 50px 0 20px; }
.footer-grid{ display:flex; flex-wrap:wrap; justify-content:space-between; align-items:center; gap: 24px; padding-bottom: 30px; }
.footer-grid p{ color: var(--text-muted); font-size: .85rem; margin-top: 6px; }
.footer-links{ display:flex; gap: 24px; }
.footer-links a{ color: var(--text-muted); font-size: .9rem; transition: var(--transition); }
.footer-links a:hover{ color: var(--accent); }
.footer-socials{ display:flex; gap: 14px; }
.footer-socials a{
  width:38px; height:38px; border-radius:50%;
  border: 1px solid var(--border);
  display:flex; align-items:center; justify-content:center;
  transition: var(--transition);
}
.footer-socials a:hover{ background: var(--accent); color:#061019; }
.footer-bottom{
  text-align:center; padding-top: 20px; border-top:1px solid var(--border);
  color: var(--text-muted); font-size: .82rem;
}
.footer-bottom i{ color: var(--accent-warm); }
.footer-bottom code{ background: var(--surface-2); padding: 2px 6px; border-radius:4px; }

/* ===== Back to top ===== */
.back-to-top{
  position: fixed; bottom: 26px; right: 26px;
  width: 48px; height:48px;
  border-radius: 50%;
  background: var(--gradient);
  color: #061019;
  display:flex; align-items:center; justify-content:center;
  box-shadow: var(--shadow);
  opacity:0; visibility:hidden; transform: translateY(20px);
  transition: var(--transition);
  z-index: 90;
}
.back-to-top.show{ opacity:1; visibility:visible; transform: translateY(0); }
.back-to-top:hover{ transform: translateY(-4px); }

/* ===== Toast (easter egg) ===== */
.toast{
  position: fixed; bottom: 30px; left: 50%;
  transform: translate(-50%, 120%);
  background: var(--surface);
  border: 1px solid var(--accent);
  color: var(--text);
  padding: 14px 22px;
  border-radius: 12px;
  font-family: var(--font-mono);
  font-size: .85rem;
  box-shadow: var(--shadow);
  z-index: 200;
  transition: transform .4s cubic-bezier(.4,0,.2,1);
  max-width: 90vw;
}
.toast.show{ transform: translate(-50%, 0); }

/* ===== Responsive ===== */
@media (max-width: 980px){
  .hero-content{ grid-template-columns:1fr; text-align:center; }
  .hero-photo{ order:-1; }
  .hero-buttons, .hero-socials, .hero-stats{ justify-content:center; }
  .hero-tagline{ margin-left:auto; margin-right:auto; }
  .about-grid, .contact-grid, .edu-grid{ grid-template-columns: 1fr; }
  .skills-grid{ grid-template-columns: 1fr; }
  .hobby-grid{ grid-template-columns: repeat(2,1fr); }
}

@media (max-width: 768px){
  .nav-links{
    position: fixed; top: 0; right: -100%;
    width: min(300px, 80vw); height: 100vh;
    background: var(--surface);
    flex-direction: column;
    padding: 100px 30px;
    gap: 26px;
    transition: right .4s cubic-bezier(.4,0,.2,1);
    box-shadow: -10px 0 40px rgba(0,0,0,0.3);
  }
  .nav-links.open{ right: 0; }
  .hamburger{ display:flex; }
  .hamburger.open span:nth-child(1){ transform: translateY(7px) rotate(45deg); }
  .hamburger.open span:nth-child(2){ opacity:0; }
  .hamburger.open span:nth-child(3){ transform: translateY(-7px) rotate(-45deg); }

  .form-row{ grid-template-columns: 1fr; }
  .cert-grid{ grid-template-columns: 1fr; }
}

@media (max-width: 520px){
  .hobby-grid{ grid-template-columns: 1fr; }
  .hero-stats{ gap: 18px; }
}