/* ============================================================
   Hitesh Jonnalagadda — Portfolio
   Premium design · Gradient accents · Bold typography
   ============================================================ */

/* --- Custom Properties ------------------------------------ */
:root {
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-surface-hover: #f0f1f3;
  --color-text: #0a0a0a;
  --color-text-secondary: #3a3a4a;
  --color-text-muted: #6b7280;
  --color-accent: #0078d4;
  --color-accent-hover: #106ebe;
  --color-accent-subtle: rgba(0, 120, 212, 0.06);
  --color-border: #e5e7eb;
  --color-card-shadow: rgba(0, 0, 0, 0.04);
  --color-nav-bg: rgba(250, 250, 250, 0.8);
  --color-nav-text: #0a0a0a;
  --color-footer-bg: #0a0a0f;
  --color-footer-text: #6b7280;

  --gradient-primary: linear-gradient(135deg, #0078d4 0%, #00b4d8 50%, #7b2ff7 100%);
  --gradient-hero: linear-gradient(135deg, #0a0a14 0%, #0d1b2a 40%, #1b1040 100%);
  --gradient-card: linear-gradient(135deg, rgba(0,120,212,0.08), rgba(123,47,247,0.08));
  --gradient-border: linear-gradient(135deg, #0078d4, #00b4d8, #7b2ff7);

  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --max-width: 1120px;
  --nav-height: 72px;
  --radius: 16px;
  --radius-sm: 10px;

  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 2rem;
  --space-xl: 4rem;
  --space-2xl: 7rem;
}

[data-theme="dark"] {
  --color-bg: #0a0a0f;
  --color-surface: #12121c;
  --color-surface-hover: #1a1a2a;
  --color-text: #f0f0f5;
  --color-text-secondary: #c8c8d4;
  --color-text-muted: #7a7a8e;
  --color-accent: #4da6ff;
  --color-accent-hover: #7abfff;
  --color-accent-subtle: rgba(77, 166, 255, 0.08);
  --color-border: #1e1e30;
  --color-card-shadow: rgba(0, 0, 0, 0.4);
  --color-nav-bg: rgba(10, 10, 15, 0.8);
  --color-nav-text: #f0f0f5;
  --color-footer-bg: #060608;
  --color-footer-text: #4a4a5e;
  --gradient-card: linear-gradient(135deg, rgba(0,120,212,0.06), rgba(123,47,247,0.06));
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --color-bg: #0a0a0f;
    --color-surface: #12121c;
    --color-surface-hover: #1a1a2a;
    --color-text: #f0f0f5;
    --color-text-secondary: #c8c8d4;
    --color-text-muted: #7a7a8e;
    --color-accent: #4da6ff;
    --color-accent-hover: #7abfff;
    --color-accent-subtle: rgba(77, 166, 255, 0.08);
    --color-border: #1e1e30;
    --color-card-shadow: rgba(0, 0, 0, 0.4);
    --color-nav-bg: rgba(10, 10, 15, 0.8);
    --color-nav-text: #f0f0f5;
    --color-footer-bg: #060608;
    --color-footer-text: #4a4a5e;
    --gradient-card: linear-gradient(135deg, rgba(0,120,212,0.06), rgba(123,47,247,0.06));
  }
}

/* --- Reset ------------------------------------------------ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: var(--nav-height); }

body {
  font-family: var(--font-sans);
  font-size: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.4s ease, color 0.4s ease;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-accent); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--color-accent-hover); }
:focus-visible { outline: 2px solid var(--color-accent); outline-offset: 2px; }

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

/* --- Utility --------------------------------------------- */
.container { width: 100%; max-width: var(--max-width); margin: 0 auto; padding: 0 var(--space-lg); }
.gradient-text {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.metric {
  display: inline;
  font-weight: 800; font-size: 1.1em; letter-spacing: -0.01em;
  color: var(--color-accent);
}

/* --- Navigation ------------------------------------------ */
.nav {
  position: fixed; top: 0; left: 0; right: 0;
  height: var(--nav-height);
  background: var(--color-nav-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
  transition: background-color 0.4s;
}
.nav__inner { display: flex; align-items: center; justify-content: space-between; height: 100%; }
.nav__logo { font-size: 1.25rem; font-weight: 800; color: var(--color-nav-text); letter-spacing: -0.03em; }
.nav__logo:hover { color: var(--color-accent); }
.nav__links { display: flex; align-items: center; gap: var(--space-sm); list-style: none; }
.nav__link {
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-sm);
  font-size: 0.875rem; font-weight: 500;
  color: var(--color-text-muted);
  transition: color 0.2s, background-color 0.2s;
}
.nav__link:hover { color: var(--color-text); background: var(--color-accent-subtle); }
.nav__link.active { color: var(--color-accent); }

.theme-toggle {
  background: none; border: 1px solid var(--color-border); border-radius: 50%;
  width: 38px; height: 38px; display: flex; align-items: center; justify-content: center;
  cursor: pointer; color: var(--color-text-muted); transition: all 0.2s; flex-shrink: 0;
}
.theme-toggle:hover { color: var(--color-accent); border-color: var(--color-accent); background: var(--color-accent-subtle); }
.theme-toggle svg { width: 18px; height: 18px; }
.theme-toggle .icon-moon { display: none; }
.theme-toggle .icon-sun { display: block; }
[data-theme="dark"] .theme-toggle .icon-moon { display: block; }
[data-theme="dark"] .theme-toggle .icon-sun { display: none; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .icon-moon { display: block; }
  :root:not([data-theme="light"]) .theme-toggle .icon-sun { display: none; }
}

.nav__hamburger {
  display: none; background: none; border: none; cursor: pointer;
  color: var(--color-text); padding: var(--space-sm);
}
.nav__hamburger svg { width: 24px; height: 24px; }

@media (max-width: 768px) {
  .nav__hamburger { display: block; }
  .nav__links {
    position: fixed; top: var(--nav-height); left: 0; right: 0;
    background: var(--color-nav-bg); backdrop-filter: blur(20px);
    flex-direction: column; padding: var(--space-lg); gap: var(--space-xs);
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-100%); opacity: 0; pointer-events: none;
    transition: transform 0.3s, opacity 0.3s;
  }
  .nav__links.open { transform: translateY(0); opacity: 1; pointer-events: all; }
  .nav__link { font-size: 1rem; padding: var(--space-sm) var(--space-md); width: 100%; text-align: center; }
}

/* --- Hero ------------------------------------------------ */
.hero {
  min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  background: var(--gradient-hero);
  color: #ffffff;
  padding: calc(var(--nav-height) + var(--space-xl)) var(--space-lg) var(--space-xl);
  position: relative; overflow: hidden;
}

/* Animated gradient orbs */
.hero::before,
.hero::after {
  content: ''; position: absolute; border-radius: 50%; filter: blur(80px); pointer-events: none;
  animation: orbFloat 12s ease-in-out infinite;
}
.hero::before {
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(0, 120, 212, 0.25) 0%, transparent 70%);
  top: -10%; left: -5%;
}
.hero::after {
  width: 500px; height: 500px;
  background: radial-gradient(circle, rgba(123, 47, 247, 0.2) 0%, transparent 70%);
  bottom: -10%; right: -5%;
  animation-delay: -6s;
  animation-direction: reverse;
}

@keyframes orbFloat {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(30px, -40px) scale(1.05); }
  66% { transform: translate(-20px, 20px) scale(0.95); }
}

.hero__content { position: relative; text-align: center; max-width: 820px; }

.hero__badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 16px; border-radius: 100px;
  background: rgba(255,255,255,0.08); border: 1px solid rgba(255,255,255,0.12);
  font-size: 0.8125rem; font-weight: 600; letter-spacing: 0.04em;
  color: rgba(255,255,255,0.8); margin-bottom: var(--space-lg);
  opacity: 0; transform: translateY(20px);
  animation: fadeUp 0.7s ease 0.1s forwards;
}
.hero__badge-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: #10b981; box-shadow: 0 0 8px #10b981;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(0.85); }
}

.hero__name {
  font-size: clamp(3rem, 2.5rem + 3.5vw, 5.5rem);
  font-weight: 900; line-height: 1.05; letter-spacing: -0.04em;
  margin-bottom: var(--space-md);
  opacity: 0; transform: translateY(24px);
  animation: fadeUp 0.7s ease 0.2s forwards;
}

.hero__thesis {
  font-size: clamp(1.125rem, 1rem + 0.6vw, 1.5rem);
  font-weight: 400; color: rgba(255,255,255,0.65);
  max-width: 640px; margin: 0 auto var(--space-lg);
  line-height: 1.5;
  opacity: 0; transform: translateY(24px);
  animation: fadeUp 0.7s ease 0.35s forwards;
}

.hero__thesis strong { color: rgba(255,255,255,0.95); font-weight: 600; }

.hero__cta {
  display: inline-flex; gap: var(--space-md); flex-wrap: wrap; justify-content: center;
  opacity: 0; transform: translateY(24px);
  animation: fadeUp 0.7s ease 0.5s forwards;
}

.hero__scroll-hint {
  position: absolute; bottom: 40px; left: 50%; transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  color: rgba(255,255,255,0.3); font-size: 0.75rem; letter-spacing: 0.1em;
  text-transform: uppercase;
  opacity: 0; animation: fadeUp 0.7s ease 0.8s forwards;
}
.hero__scroll-line {
  width: 1px; height: 40px; background: linear-gradient(to bottom, rgba(255,255,255,0.3), transparent);
  animation: scrollPulse 2s ease-in-out infinite;
}
@keyframes scrollPulse {
  0%, 100% { transform: scaleY(1); opacity: 1; }
  50% { transform: scaleY(0.5); opacity: 0.3; }
}

@keyframes fadeUp {
  to { opacity: 1; transform: translateY(0); }
}

/* --- Buttons --------------------------------------------- */
.btn {
  display: inline-flex; align-items: center; gap: var(--space-sm);
  padding: 0.875rem 2rem; font-size: 0.9375rem; font-weight: 600;
  border-radius: var(--radius-sm); border: none; cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s, background-color 0.2s;
}
.btn:hover { transform: translateY(-2px); }

.btn--primary {
  background: var(--gradient-primary); color: #ffffff;
  box-shadow: 0 4px 24px rgba(0, 120, 212, 0.3);
}
.btn--primary:hover { box-shadow: 0 8px 32px rgba(0, 120, 212, 0.45); color: #fff; }

.btn--outline {
  background: transparent; color: #ffffff;
  border: 1.5px solid rgba(255,255,255,0.2);
}
.btn--outline:hover { border-color: rgba(255,255,255,0.5); color: #fff; background: rgba(255,255,255,0.05); }

.btn--surface {
  background: var(--color-surface); color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn--surface:hover { background: var(--color-surface-hover); box-shadow: 0 4px 20px var(--color-card-shadow); }

/* --- Section --------------------------------------------- */
.section { padding: var(--space-2xl) var(--space-lg); }
.section--alt { background: var(--color-surface); }

.section__header { text-align: center; margin-bottom: var(--space-xl); }
.section__label {
  font-size: 0.8125rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.12em; margin-bottom: var(--space-sm);
  background: var(--gradient-primary);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.section__title {
  font-size: clamp(2rem, 1.5rem + 2vw, 3rem);
  font-weight: 900; letter-spacing: -0.03em; line-height: 1.15;
}
.section__subtitle {
  color: var(--color-text-muted); max-width: 560px;
  margin: var(--space-md) auto 0; font-size: 1.0625rem;
}

/* --- About ----------------------------------------------- */
.about__grid {
  display: grid; grid-template-columns: 0.9fr 1.1fr;
  gap: var(--space-xl); align-items: center;
}
.about__image {
  width: 100%; aspect-ratio: 4/5; border-radius: var(--radius);
  object-fit: cover; object-position: center top;
  border: 2px solid var(--color-border);
}
.about__text p { margin-bottom: var(--space-md); color: var(--color-text-secondary); font-size: 1.0625rem; }
.about__text p:first-child { color: var(--color-text); font-size: 1.1875rem; font-weight: 500; }

.about__highlights {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md); margin-top: var(--space-lg);
}
.about__highlight {
  text-align: center; padding: var(--space-lg) var(--space-md);
  background: var(--gradient-card); border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  position: relative; overflow: hidden;
}
.about__highlight::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: var(--gradient-primary);
}
.about__highlight-value { font-size: 1.75rem; font-weight: 900; }
.about__highlight-label { font-size: 0.8125rem; color: var(--color-text-muted); margin-top: 2px; }

@media (max-width: 768px) {
  .about__grid { grid-template-columns: 1fr; gap: var(--space-lg); }
  .about__image { max-width: 320px; margin: 0 auto; }
}

/* --- Experience ------------------------------------------ */
.timeline { position: relative; max-width: 760px; margin: 0 auto; }
.timeline::before {
  content: ''; position: absolute; left: 23px; top: 0; bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--color-accent), var(--color-border));
}
.timeline__item { position: relative; padding-left: 68px; padding-bottom: var(--space-xl); }
.timeline__item:last-child { padding-bottom: 0; }

.timeline__dot {
  position: absolute; left: 14px; top: 4px;
  width: 20px; height: 20px; border-radius: 50%;
  background: var(--color-accent);
  border: 3px solid var(--color-bg);
  box-shadow: 0 0 0 2px var(--color-accent);
  transition: all 0.3s;
}
.timeline__item--past .timeline__dot {
  background: var(--color-text-muted);
  box-shadow: 0 0 0 2px var(--color-text-muted);
}

.timeline__role { font-size: 1.1875rem; font-weight: 800; letter-spacing: -0.01em; }
.timeline__company { font-size: 0.9375rem; font-weight: 600; margin-bottom: 2px; }
.timeline__company .gradient-text { font-weight: 700; }
.timeline__period { font-size: 0.8125rem; color: var(--color-text-muted); margin-bottom: var(--space-sm); }
.timeline__desc { color: var(--color-text-muted); font-size: 0.9375rem; line-height: 1.65; }

/* --- Thesis / Perspective -------------------------------- */
.thesis__grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-lg);
}
.thesis-card {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius); padding: var(--space-lg) var(--space-lg) var(--space-lg);
  position: relative; overflow: hidden;
  transition: transform 0.3s, box-shadow 0.3s;
}
.thesis-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px var(--color-card-shadow);
}
.thesis-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: var(--gradient-primary); opacity: 0;
  transition: opacity 0.3s;
}
.thesis-card:hover::before { opacity: 1; }

.thesis-card__icon {
  width: 48px; height: 48px; border-radius: var(--radius-sm);
  background: var(--gradient-card);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: var(--space-md); color: var(--color-accent);
}
.thesis-card__icon svg { width: 24px; height: 24px; }
.thesis-card__title { font-size: 1.125rem; font-weight: 800; margin-bottom: var(--space-sm); letter-spacing: -0.01em; }
.thesis-card__text { color: var(--color-text-muted); font-size: 0.9375rem; line-height: 1.65; }

/* --- Skills (tag cloud style) ---------------------------- */
.skills__grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-lg);
}
.skill-card {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius); padding: var(--space-lg);
  transition: transform 0.2s, box-shadow 0.2s;
}
.skill-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px var(--color-card-shadow);
}
.skill-card__icon {
  width: 44px; height: 44px; border-radius: var(--radius-sm);
  background: var(--gradient-card);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: var(--space-md); color: var(--color-accent);
}
.skill-card__icon svg { width: 22px; height: 22px; }
.skill-card__title { font-size: 1.0625rem; font-weight: 800; margin-bottom: var(--space-sm); }
.skill-card__tags { display: flex; flex-wrap: wrap; gap: var(--space-sm); }
.skill-tag {
  font-size: 0.8125rem; padding: 5px 12px;
  background: var(--color-bg); border: 1px solid var(--color-border);
  border-radius: 100px; color: var(--color-text-muted);
  transition: all 0.2s;
}
.skill-tag:hover { background: var(--color-accent-subtle); color: var(--color-accent); border-color: var(--color-accent); }

/* --- Certifications banner ------------------------------- */
.certs {
  display: flex; flex-wrap: wrap; justify-content: center;
  gap: var(--space-md); padding: var(--space-lg) 0;
}
.cert-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 16px; border-radius: 100px;
  background: var(--color-surface); border: 1px solid var(--color-border);
  font-size: 0.8125rem; font-weight: 600; color: var(--color-text-secondary);
  transition: all 0.2s;
}
.cert-badge:hover { border-color: var(--color-accent); color: var(--color-accent); }
.cert-badge svg { width: 16px; height: 16px; color: var(--color-accent); }

/* --- Contact --------------------------------------------- */
.contact__links {
  display: flex; justify-content: center; gap: var(--space-lg); flex-wrap: wrap;
  max-width: 900px; margin: 0 auto;
}
.contact__link-card {
  display: flex; flex-direction: column; align-items: center; gap: var(--space-sm);
  padding: var(--space-xl) var(--space-lg);
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius); min-width: 220px; flex: 1;
  text-align: center; color: var(--color-text);
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}
.contact__link-card:hover {
  transform: translateY(-4px); color: var(--color-text);
  box-shadow: 0 12px 40px var(--color-card-shadow);
  border-color: var(--color-accent);
}
.contact__link-card svg { width: 28px; height: 28px; color: var(--color-accent); }
.contact__link-label { font-size: 1.0625rem; font-weight: 800; }
.contact__link-handle { font-size: 0.875rem; color: var(--color-text-muted); }

/* --- Footer ---------------------------------------------- */
.footer {
  background: var(--color-footer-bg); color: var(--color-footer-text);
  padding: var(--space-xl) var(--space-lg) var(--space-lg);
}
.footer__inner {
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: var(--space-md);
}
.footer__copy { font-size: 0.8125rem; }
.footer__socials { display: flex; gap: var(--space-md); }
.footer__social {
  width: 38px; height: 38px; display: flex; align-items: center; justify-content: center;
  border-radius: 50%; border: 1px solid rgba(255,255,255,0.1);
  color: var(--color-footer-text); transition: all 0.2s;
}
.footer__social:hover { color: #4da6ff; border-color: #4da6ff; background: rgba(77,166,255,0.08); }
.footer__social svg { width: 18px; height: 18px; }

/* --- Scroll reveal --------------------------------------- */
.reveal {
  opacity: 0; transform: translateY(28px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-stagger > .reveal { transition-delay: calc(var(--i, 0) * 0.1s); }

/* --- Quote block ----------------------------------------- */
.quote-block {
  text-align: center; padding: var(--space-2xl) var(--space-lg);
  background: var(--gradient-hero); color: #fff;
  position: relative; overflow: hidden;
}
.quote-block::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse at center, rgba(0,120,212,0.12) 0%, transparent 70%);
  pointer-events: none;
}
.quote-block__text {
  position: relative; font-size: clamp(1.5rem, 1.2rem + 1.5vw, 2.5rem);
  font-weight: 800; line-height: 1.3; letter-spacing: -0.02em;
  max-width: 800px; margin: 0 auto var(--space-md);
}
.quote-block__attr {
  position: relative; font-size: 0.9375rem;
  color: rgba(255,255,255,0.5); font-weight: 500;
}

/* --- Scrollbar ------------------------------------------- */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--color-bg); }
::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--color-text-muted); }

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