/* =============================================================================
   style.css — Arnav Chopra Portfolio
   Dark theme, responsive, single-page layout
============================================================================= */

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

:root {
  --bg:           #0a0a0f;
  --bg-alt:       #0d0d14;
  --surface:      #111118;
  --surface-2:    rgba(17, 17, 24, 0.7);
  --border:       #1c1c2a;
  --border-hover: rgba(108, 99, 255, 0.45);
  --accent:       #6c63ff;
  --accent-2:     #a78bfa;
  --accent-glow:  rgba(108, 99, 255, 0.2);
  --text:         #e2e8f0;
  --text-muted:   #94a3b8;
  --muted:        #5a6478;
  --radius:       0.625rem;
  --radius-lg:    1.125rem;
  --nav-h:        64px;
}

[data-theme="light"] {
  --bg:           #f4f4f8;
  --bg-alt:       #ebebf2;
  --surface:      #ffffff;
  --surface-2:    rgba(255, 255, 255, 0.75);
  --border:       #d8d8e8;
  --border-hover: rgba(108, 99, 255, 0.4);
  --accent:       #5b52d4;
  --accent-2:     #6c63ff;
  --accent-glow:  rgba(108, 99, 255, 0.12);
  --text:         #18182a;
  --text-muted:   #52526e;
  --muted:        #8888a4;
}

/* Gradient-text elements that hardcode #fff must be overridden in light mode */
[data-theme="light"] .hero-name {
  background: linear-gradient(135deg, #18182a 30%, var(--accent-2) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
[data-theme="light"] .nav-logo {
  background: linear-gradient(135deg, #18182a 30%, var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
[data-theme="light"] .section-title {
  background: linear-gradient(135deg, #18182a 40%, var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-h);
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  font-size: 1rem;
  line-height: 1.7;
  overflow-x: hidden;
  transition: background-color 0.25s ease, color 0.25s ease;
}

a { color: inherit; text-decoration: none; }
img, video { max-width: 100%; display: block; }

::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

/* ── Utility ──────────────────────────────────────────────────────────────── */

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 6rem 0;
}

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

.section-title {
  font-size: clamp(1.75rem, 3.5vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.2;
  margin-bottom: 0.5rem;
  background: linear-gradient(135deg, #fff 40%, var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-sub {
  color: var(--text-muted);
  margin-bottom: 3rem;
  max-width: 560px;
  font-size: 0.95rem;
}

.badge {
  display: inline-block;
  background: rgba(108, 99, 255, 0.12);
  border: 1px solid rgba(108, 99, 255, 0.28);
  color: var(--accent-2);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.11em;
  text-transform: uppercase;
  padding: 0.28rem 0.85rem;
  border-radius: 999px;
}

.inline-link {
  color: var(--accent-2);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.inline-link:hover { opacity: 0.8; }

/* ── Buttons ──────────────────────────────────────────────────────────────── */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: opacity 0.2s, transform 0.2s, box-shadow 0.2s, border-color 0.2s, color 0.2s;
}
.btn:hover { opacity: 0.88; transform: translateY(-2px); }
.btn svg { width: 17px; height: 17px; flex-shrink: 0; }

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 0 18px rgba(108, 99, 255, 0.32);
}
.btn-primary:hover { box-shadow: 0 0 30px rgba(108, 99, 255, 0.5); }

.btn-outline {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}
.btn-outline:hover { border-color: var(--accent); color: var(--accent-2); }

.btn-sm { padding: 0.4rem 0.9rem; font-size: 0.8rem; }

.text-link {
  color: var(--accent-2);
  font-size: 0.9rem;
  font-weight: 500;
  text-underline-offset: 3px;
}
.text-link:hover { text-decoration: underline; }

/* ── Scroll-reveal ────────────────────────────────────────────────────────── */

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}
.reveal.visible {
  opacity: 1;
  transform: none;
}

/* =============================================================================
   NAVBAR
============================================================================= */

#navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 1000;
  border-bottom: 1px solid transparent;
  transition: background 0.3s, border-color 0.3s, box-shadow 0.3s;
}

#navbar.scrolled {
  background: rgba(10, 10, 15, 0.9);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-color: var(--border);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
}
[data-theme="light"] #navbar.scrolled {
  background: rgba(244, 244, 248, 0.92);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 100%;
}

.nav-logo {
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, #fff 30%, var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 2rem;
  align-items: center;
}
.nav-links a {
  font-size: 0.87rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--text); }

.theme-toggle {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  padding: 0.35rem 0.45rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  flex-shrink: 0;
  line-height: 1;
  transition: border-color 0.2s, color 0.2s;
}
.theme-toggle:hover {
  border-color: var(--accent);
  color: var(--accent-2);
}
.theme-toggle svg {
  width: 18px;
  height: 18px;
  display: block;
}

.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(--text);
  border-radius: 2px;
  transition: transform 0.28s, opacity 0.28s;
}

/* =============================================================================
   HERO
============================================================================= */

#hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  text-align: center;
  padding: calc(var(--nav-h) + 2rem) 1.5rem 5rem;
}

.hero-bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.28;
  pointer-events: none;
  mask-image: radial-gradient(ellipse 85% 85% at 50% 50%, black 30%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 85% 85% at 50% 50%, black 30%, transparent 100%);
}

.hero-glow {
  position: absolute;
  top: 40%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 640px;
  height: 640px;
  background: radial-gradient(circle, rgba(108, 99, 255, 0.13) 0%, transparent 65%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  max-width: 680px;
  animation: heroFadeUp 0.7s ease 0.1s both;
}

@keyframes heroFadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: none; }
}

.hero-name {
  font-size: clamp(2.75rem, 8vw, 5.5rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.05;
  background: linear-gradient(135deg, #ffffff 30%, var(--accent-2) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-title {
  font-size: clamp(0.95rem, 2.2vw, 1.15rem);
  color: var(--text-muted);
  font-weight: 400;
  letter-spacing: 0.015em;
}

.hero-sub {
  font-size: 0.93rem;
  color: var(--muted);
  max-width: 460px;
  line-height: 1.75;
  margin-top: 0.1rem;
}

.hero-ctas {
  display: flex;
  gap: 0.85rem;
  margin-top: 0.5rem;
  flex-wrap: wrap;
  justify-content: center;
}

.hero-scroll-hint {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.2rem;
  color: var(--muted);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  animation: scrollBounce 2.2s ease-in-out infinite;
}
.hero-scroll-hint svg { width: 16px; height: 16px; }

@keyframes scrollBounce {
  0%, 100% { transform: translateX(-50%) translateY(0);   opacity: 0.5; }
  50%       { transform: translateX(-50%) translateY(7px); opacity: 1;   }
}

/* =============================================================================
   ABOUT
============================================================================= */

.about-grid {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 4rem;
  align-items: start;
}

.about-photo {
  width: 100%;
}

.photo-placeholder {
  aspect-ratio: 1;
  border-radius: var(--radius-lg);
  border: 2px dashed var(--border);
  background: var(--surface);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  color: var(--muted);
  font-size: 0.78rem;
}
.photo-placeholder svg {
  width: 44px;
  height: 44px;
  opacity: 0.35;
}

.about-text {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.about-bio {
  color: var(--text-muted);
  font-size: 0.97rem;
  line-height: 1.8;
}

.about-links {
  display: flex;
  gap: 1.5rem;
  margin-top: 0.5rem;
  flex-wrap: wrap;
}

/* =============================================================================
   EXPERIENCE TIMELINE
============================================================================= */

.timeline {
  position: relative;
  padding-left: 2.5rem;
  margin-top: 0.5rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent) 0%, transparent 100%);
  border-radius: 2px;
}

.timeline-item {
  position: relative;
  padding-bottom: 2.75rem;
}
.timeline-item:last-child { padding-bottom: 0; }

.timeline-dot {
  position: absolute;
  left: -2.18rem;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg-alt);
  box-shadow: 0 0 0 3px rgba(108, 99, 255, 0.2);
}

.timeline-date {
  display: block;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-2);
  letter-spacing: 0.07em;
  text-transform: uppercase;
  margin-bottom: 0.3rem;
}

.timeline-role {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.2rem;
}

.timeline-org {
  font-size: 0.87rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.timeline-desc {
  font-size: 0.9rem;
  color: var(--muted);
  line-height: 1.7;
}

/* =============================================================================
   PROJECTS
============================================================================= */

.projects-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

.project-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: border-color 0.25s, transform 0.25s, box-shadow 0.25s;
}
.project-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: 0 20px 48px rgba(0, 0, 0, 0.45), 0 0 0 1px rgba(108, 99, 255, 0.08);
}

/* Media area */
.card-media {
  position: relative;
  aspect-ratio: 16 / 9;
  background: var(--surface-2);
  overflow: hidden;
  border-bottom: 1px solid var(--border);
}
.card-media img,
.card-media video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.card-media-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  color: var(--muted);
  font-size: 0.75rem;
  background: linear-gradient(135deg, #0f0f18, #0a0a14);
}
.card-media-placeholder svg {
  width: 32px;
  height: 32px;
  opacity: 0.25;
}
.card-demo-badge {
  position: absolute;
  top: 0.55rem;
  right: 0.55rem;
  background: rgba(108, 99, 255, 0.88);
  color: #fff;
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.18rem 0.55rem;
  border-radius: 999px;
}

/* Card body */
.card-body {
  padding: 1.1rem 1.2rem 1rem;
  display: flex;
  flex-direction: column;
  flex: 1;
  gap: 0.55rem;
}
.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}
.card-tag {
  font-size: 0.67rem;
  font-weight: 600;
  padding: 0.16rem 0.55rem;
  border-radius: 999px;
  background: rgba(108, 99, 255, 0.1);
  border: 1px solid rgba(108, 99, 255, 0.18);
  color: var(--accent-2);
}
.card-title {
  font-size: 0.97rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.35;
}
.card-desc {
  font-size: 0.83rem;
  color: var(--text-muted);
  line-height: 1.65;
  flex: 1;
}
.card-footer {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
  margin-top: auto;
}
.card-footer .btn svg { width: 14px; height: 14px; }

/* =============================================================================
   SKILLS
============================================================================= */

.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

.skill-group {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}

.skill-group-title {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent-2);
  margin-bottom: 1rem;
}

.skill-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.skill-badge {
  font-size: 0.82rem;
  font-weight: 500;
  padding: 0.28rem 0.7rem;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-muted);
}

.skill-placeholder {
  opacity: 0.45;
  font-style: italic;
}

/* =============================================================================
   CONTACT
============================================================================= */

.contact-inner {
  text-align: center;
}

.contact-links {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.contact-card {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  padding: 1rem 1.75rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
  transition: border-color 0.2s, color 0.2s, transform 0.2s, box-shadow 0.2s;
}
.contact-card:hover {
  border-color: var(--accent);
  color: var(--text);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(108, 99, 255, 0.12);
}
.contact-card svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

/* =============================================================================
   FOOTER
============================================================================= */

#footer {
  text-align: center;
  padding: 2rem 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.78rem;
  color: var(--muted);
}

/* =============================================================================
   RESPONSIVE
============================================================================= */

@media (max-width: 960px) {
  .projects-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 720px) {
  .about-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .about-photo {
    max-width: 200px;
    margin: 0 auto;
  }
  .skills-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 600px) {
  .projects-grid {
    grid-template-columns: 1fr;
  }
  .section {
    padding: 4rem 0;
  }

  /* Mobile nav */
  .nav-links {
    display: none;
    position: fixed;
    top: var(--nav-h);
    left: 0;
    right: 0;
    background: rgba(10, 10, 15, 0.97);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    flex-direction: column;
    gap: 0;
    padding: 0.5rem 0 1rem;
    border-bottom: 1px solid var(--border);
  }
  .nav-links.open { display: flex; }
  .nav-links li { width: 100%; }
  .nav-links a {
    display: block;
    padding: 0.85rem 1.5rem;
    font-size: 0.95rem;
  }
  .nav-toggle { display: flex; }

  .contact-links { flex-direction: column; align-items: center; }
  .contact-card { width: 100%; max-width: 280px; justify-content: center; }
}