/* =========================================
   Rahul Kumar — Portfolio
   Theme: Dark + Modern Cyan Accent
   ========================================= */

:root {
  --bg: #07090f;
  --bg-2: #0d1320;
  --surface: #121a2b;
  --surface-2: #19233a;
  --border: rgba(255, 255, 255, 0.08);
  --text: #e6edf7;
  --text-dim: #a0acc2;
  --muted: #6b7691;
  --accent: #22d3ee;            /* cyan-400 */
  --accent-2: #38bdf8;           /* sky-400  */
  --accent-soft: rgba(34, 211, 238, 0.12);
  --accent-glow: 0 0 0 1px rgba(34,211,238,0.25), 0 8px 32px rgba(34,211,238,0.18);
  --success: #4ade80;
  --radius: 12px;
  --radius-sm: 8px;
  --maxw: 1180px;
  --container-x: clamp(20px, 6vw, 80px);
  --font: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  --mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
}

/* ------------ Reset ------------ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img { max-width: 100%; display: block; }
a { color: var(--accent); text-decoration: none; transition: color .2s; }
a:hover { color: var(--accent-2); }
button { font-family: inherit; cursor: pointer; }
ul { list-style: none; }

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

section { padding: 90px 0; }
.sub-title {
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 700;
  color: var(--text);
  margin-bottom: 40px;
  position: relative;
  display: inline-block;
  letter-spacing: -0.02em;
}
.sub-title::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -10px;
  width: 56px;
  height: 4px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  border-radius: 4px;
}

/* ------------ Buttons ------------ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 15px;
  text-decoration: none;
  border: 1px solid transparent;
  transition: transform .2s ease, background .2s ease, box-shadow .2s ease, border-color .2s ease;
  cursor: pointer;
  letter-spacing: 0.01em;
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #051018;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--accent-glow); color: #051018; }
.btn-outline {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}
.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
}
.btn-center { display: flex; margin: 50px auto 0; width: fit-content; }

/* ============== HEADER / HERO ============== */
#header {
  position: relative;
  min-height: 100vh;
  background:
    radial-gradient(60% 60% at 80% 10%, rgba(34,211,238,0.10), transparent 60%),
    radial-gradient(60% 50% at 10% 90%, rgba(56,189,248,0.08), transparent 60%),
    linear-gradient(180deg, #07090f 0%, #0a1020 100%);
  overflow: hidden;
}
#header::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.025) 1px, transparent 1px);
  background-size: 56px 56px;
  pointer-events: none;
  mask-image: radial-gradient(ellipse at center, black 40%, transparent 80%);
}

nav {
  position: relative;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 26px 0;
}
.brand .logo { width: 110px; height: auto; }
nav ul {
  display: flex;
  gap: 8px;
  align-items: center;
}
nav ul li a {
  position: relative;
  display: inline-block;
  color: var(--text-dim);
  font-size: 15px;
  font-weight: 500;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  transition: color .2s, background .2s;
}
nav ul li a:hover { color: var(--text); background: rgba(255,255,255,0.04); }
nav ul li a.nav-cta {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #051018;
  padding: 10px 20px;
  font-weight: 600;
  margin-left: 8px;
}
nav ul li a.nav-cta:hover { transform: translateY(-1px); box-shadow: var(--accent-glow); background: linear-gradient(135deg, var(--accent), var(--accent-2)); }

.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px;
  width: 44px;
  height: 44px;
  flex-direction: column;
  gap: 5px;
  justify-content: center;
  align-items: center;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  transition: transform .25s, opacity .25s;
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.header-text {
  position: relative;
  z-index: 5;
  margin-top: clamp(60px, 12vh, 130px);
  max-width: 760px;
}
.eyebrow {
  display: inline-block;
  color: var(--accent);
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 6px 14px;
  background: var(--accent-soft);
  border: 1px solid rgba(34,211,238,0.25);
  border-radius: 999px;
  margin-bottom: 22px;
}
.header-text h1 {
  font-size: clamp(38px, 6vw, 72px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 22px;
}
.header-text h1 span {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.header-text .lede {
  font-size: clamp(16px, 1.6vw, 19px);
  color: var(--text-dim);
  max-width: 620px;
  margin-bottom: 36px;
}
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }

/* ============== ABOUT ============== */
#about { background: var(--bg-2); }
.row {
  display: flex;
  gap: 56px;
  align-items: flex-start;
  flex-wrap: wrap;
}
.about-col-1 {
  flex: 1 1 320px;
  max-width: 380px;
}
.about-col-1 img {
  width: 100%;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  filter: grayscale(0.05);
}
.about-col-2 {
  flex: 1 1 520px;
  color: var(--text-dim);
}
.about-col-2 p { margin-bottom: 16px; font-size: 16px; }
.about-col-2 p strong { color: var(--text); font-weight: 600; }

/* tabs */
.tab-titles {
  display: flex;
  gap: 10px;
  margin: 32px 0 28px;
  flex-wrap: wrap;
  border-bottom: 1px solid var(--border);
}
.tab-links {
  background: transparent;
  border: 0;
  color: var(--text-dim);
  font-size: 15px;
  font-weight: 600;
  padding: 12px 6px;
  margin-right: 18px;
  position: relative;
  transition: color .2s;
}
.tab-links:hover { color: var(--text); }
.tab-links::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width .3s;
}
.tab-links.active-link { color: var(--accent); }
.tab-links.active-link::after { width: 100%; }

.tab-contents { display: none; padding-top: 8px; }
.tab-contents.active-tab { display: block; animation: fadeIn .4s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(6px);} to { opacity:1; transform:none;} }

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
}
.skills-grid li {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  transition: border-color .2s, transform .2s;
}
.skills-grid li:hover { border-color: var(--accent); transform: translateY(-2px); }
.skills-grid li strong {
  display: block;
  color: var(--text);
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 4px;
}
.skills-grid li span {
  display: block;
  color: var(--muted);
  font-size: 13px;
}

/* experience & education cards */
.exp-item, .edu-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 24px;
  margin-bottom: 16px;
  transition: border-color .2s;
}
.exp-item:hover, .edu-item:hover { border-color: rgba(34,211,238,0.35); }
.exp-head, .edu-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 10px;
}
.exp-role, .edu-course {
  font-weight: 700;
  color: var(--text);
  font-size: 17px;
}
.exp-meta, .edu-meta {
  color: var(--accent);
  font-size: 13px;
  font-family: var(--mono);
  font-weight: 500;
}
.exp-desc, .edu-desc { color: var(--text-dim); margin-bottom: 10px; font-size: 15px; }
.exp-resp, .edu-points { margin-left: 18px; color: var(--text-dim); margin-bottom: 12px; }
.exp-resp li, .edu-points li { margin: 6px 0; line-height: 1.55; list-style: disc; font-size: 14px; }
.exp-links { margin-top: 12px; display: flex; gap: 10px; flex-wrap: wrap; }

.cert-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  text-decoration: none;
  color: var(--accent);
  border: 1px solid rgba(34,211,238,0.3);
  padding: 7px 14px;
  border-radius: 999px;
  background: var(--accent-soft);
  font-size: 13px;
  font-weight: 500;
  transition: background .2s, transform .15s;
}
.cert-link:hover { background: var(--accent); color: #051018; transform: translateY(-2px); }

/* ============== SERVICES ============== */
.services-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 22px;
  margin-top: 16px;
}
.services-list article {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 32px 26px;
  border-radius: var(--radius);
  transition: transform .25s ease, border-color .25s ease, background .25s ease;
  position: relative;
  overflow: hidden;
}
.services-list article::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(34,211,238,0.06), transparent 60%);
  opacity: 0;
  transition: opacity .25s;
}
.services-list article:hover {
  transform: translateY(-6px);
  border-color: var(--accent);
}
.services-list article:hover::before { opacity: 1; }
.services-list article i {
  font-size: 32px;
  color: var(--accent);
  margin-bottom: 20px;
  display: inline-block;
  padding: 14px;
  background: var(--accent-soft);
  border-radius: var(--radius-sm);
}
.services-list article h3 {
  font-size: 19px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 10px;
}
.services-list article p {
  color: var(--text-dim);
  font-size: 14.5px;
  margin-bottom: 16px;
  line-height: 1.6;
}
.services-list article a {
  color: var(--accent);
  font-size: 14px;
  font-weight: 600;
}

/* ============== PORTFOLIO ============== */
#portfolio { background: var(--bg-2); }
.work-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin-top: 16px;
}
.work {
  border-radius: var(--radius);
  position: relative;
  overflow: hidden;
  aspect-ratio: 4 / 3;
  background: var(--surface);
  border: 1px solid var(--border);
}
.work img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform .5s ease;
}
.layer {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(7,9,15,0.2) 0%, rgba(7,9,15,0.95) 70%);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 24px;
  opacity: 0;
  transition: opacity .4s ease;
}
.layer h3 {
  color: var(--text);
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  transform: translateY(12px);
  transition: transform .4s ease;
}
.layer p {
  color: var(--text-dim);
  font-size: 14px;
  margin-bottom: 14px;
  transform: translateY(12px);
  transition: transform .4s ease .05s;
}
.layer a {
  align-self: flex-start;
  color: #051018;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  transform: translateY(12px);
  transition: transform .4s ease .1s;
}
.work:hover img { transform: scale(1.06); }
.work:hover .layer { opacity: 1; }
.work:hover .layer h3,
.work:hover .layer p,
.work:hover .layer a { transform: translateY(0); }

/* ============== CONTACT ============== */
.contact-row { gap: 40px; }
.contact-left { flex: 1 1 320px; }
.contact-right { flex: 1 1 420px; }
.contact-intro { color: var(--text-dim); margin-bottom: 24px; max-width: 380px; }
.contact-left p {
  margin: 12px 0;
  color: var(--text-dim);
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 15px;
}
.contact-left p i {
  color: var(--accent);
  font-size: 18px;
  width: 36px;
  height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-soft);
  border-radius: var(--radius-sm);
}
.contact-left p a { color: var(--text-dim); }
.contact-left p a:hover { color: var(--accent); }
.social-icons { margin: 24px 0; display: flex; gap: 12px; }
.social-icons a {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-dim);
  font-size: 18px;
  transition: all .2s;
}
.social-icons a:hover {
  color: var(--accent);
  border-color: var(--accent);
  transform: translateY(-3px);
}

/* contact form */
.contact-form {
  background: var(--surface);
  padding: 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}
.contact-form h3 { color: var(--text); font-size: 20px; margin-bottom: 18px; font-weight: 600; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 12px 14px;
  margin: 8px 0;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-family: inherit;
  font-size: 15px;
  outline: none;
  transition: border-color .2s, box-shadow .2s;
}
.contact-form input::placeholder,
.contact-form textarea::placeholder { color: var(--muted); }
.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(34,211,238,0.15);
}
.contact-form textarea { resize: vertical; min-height: 120px; }
.contact-form .btn { width: 100%; margin-top: 12px; }
.cf-status { margin-top: 12px; color: var(--success); font-size: 14px; min-height: 18px; }

/* ============== FEEDBACK PANEL ============== */
#feedback-panel { margin-top: 60px; }
.feedback-summary {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
  flex-wrap: wrap;
  gap: 14px;
}
.summary-left { display: flex; align-items: center; gap: 14px; }
.avg-rating {
  font-size: 32px;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.avg-stars { font-size: 18px; color: var(--accent); }
.rating-count { color: var(--text-dim); font-size: 13px; }

.feedback-list { display: flex; flex-direction: column; gap: 12px; margin-bottom: 16px; }
.feedback-card {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 16px 18px;
  border-radius: var(--radius);
  color: var(--text-dim);
  transition: transform .2s, border-color .2s;
}
.feedback-card:hover { transform: translateY(-2px); border-color: rgba(34,211,238,0.3); }
.feedback-card .meta { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; flex-wrap: wrap; gap: 8px; }
.feedback-card .meta .left { font-weight: 600; color: var(--text); display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.feedback-card .meta .role { color: var(--accent); font-size: 13px; font-weight: 500; }
.feedback-card .meta .date { color: var(--muted); font-size: 12px; }
.feedback-card .comment { color: var(--text-dim); font-size: 14.5px; line-height: 1.55; }
.star-display { color: var(--accent); font-size: 14px; margin-left: 4px; }
.no-feedback { color: var(--muted); text-align: center; padding: 20px; }

.feedback-form-wrap {
  margin-top: 16px;
  background: var(--surface);
  padding: 22px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}
.feedback-form-wrap.hidden { display: none; }
.feedback-form-wrap h3 { color: var(--text); font-size: 18px; margin-bottom: 14px; }
#fb-name, #fb-role, #fb-message {
  width: 100%;
  background: var(--bg-2);
  padding: 11px 13px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  margin: 8px 0;
  outline: none;
  font-family: inherit;
  font-size: 14.5px;
}
#fb-name:focus, #fb-role:focus, #fb-message:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(34,211,238,0.15);
}
.rating-input { display: flex; align-items: center; gap: 10px; margin: 12px 0; flex-wrap: wrap; }
.rating-input label { color: var(--text-dim); font-size: 14px; }
.star-input { display: inline-flex; gap: 4px; }
.star-input .star {
  font-size: 24px;
  cursor: pointer;
  color: var(--muted);
  transition: color .15s, transform .15s;
  user-select: none;
}
.star-input .star.active,
.star-input .star:hover { color: var(--accent); }
.fb-actions { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; margin-top: 10px; }

/* ============== FOOTER ============== */
.site-footer {
  background: var(--bg);
  padding: 36px 0;
  border-top: 1px solid var(--border);
}
.site-footer p {
  color: var(--text-dim);
  text-align: center;
  font-size: 14px;
}
.site-footer a { color: var(--accent); margin-left: 12px; }

/* ============== RESPONSIVE ============== */
@media (max-width: 900px) {
  .nav-toggle { display: inline-flex; }
  nav ul {
    position: absolute;
    top: 84px;
    left: var(--container-x);
    right: var(--container-x);
    flex-direction: column;
    align-items: stretch;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 14px;
    gap: 4px;
    box-shadow: 0 16px 40px rgba(0,0,0,0.5);
    transform: scaleY(0);
    transform-origin: top;
    opacity: 0;
    transition: transform .25s, opacity .25s;
    pointer-events: none;
  }
  nav ul.open {
    transform: scaleY(1);
    opacity: 1;
    pointer-events: auto;
  }
  nav ul li { width: 100%; }
  nav ul li a { display: block; padding: 12px 16px; }
  nav ul li a.nav-cta { text-align: center; margin: 6px 0 0; }
  .row { gap: 32px; }
  .form-row { grid-template-columns: 1fr; }
  section { padding: 70px 0; }
  .feedback-summary { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 500px) {
  .header-text h1 { font-size: 38px; }
  .hero-cta { flex-direction: column; }
  .hero-cta .btn { width: 100%; }
  .btn { padding: 12px 22px; font-size: 14px; }
  .contact-form { padding: 20px; }
}

/* ============== UTILITIES ============== */
.hidden { display: none !important; }
::selection { background: var(--accent); color: #051018; }

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