/* =====================
   Deepthi Chowla Portfolio Styles
   Color palette:
   Primary: #1E3A8A (Navy Blue)
   Secondary: #3B82F6 (Bright Blue)
   Accent: #F59E0B (Amber)
   Background: #F9FAFB (Off-White)
   Text: #111827 (Dark Grey)
===================== */

:root {
  /* Cinematic Dark Theme */
  --color-primary: #93c5fd; /* Light blue headings */
  --color-secondary: #3b82f6; /* Electric blue accent */
  --color-accent: #f59e0b; /* Amber button */
  --color-bg: #0b1020; /* Deep navy black */
  --color-surface: #11162a; /* Elevated surfaces */
  --color-text: #e5e7eb; /* Light foreground */
  --color-muted: #94a3b8; /* Muted text */

  --radius: 12px;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
  --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.12);
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  color: var(--color-text);
  background: radial-gradient(1200px 600px at 20% 10%, rgba(59,130,246,0.08), transparent 60%),
              radial-gradient(800px 400px at 80% 0%, rgba(245,158,11,0.06), transparent 60%),
              var(--color-bg);
  line-height: 1.6;
}

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

.container {
  width: min(1100px, 92%);
  margin: 0 auto;
}

/* ===================== NAVIGATION ===================== */
.site-header { color: #fff; position: relative; overflow: hidden; }
.site-header::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(2,6,23,0.6) 0%, rgba(2,6,23,0.3) 40%, rgba(2,6,23,0.85) 100%),
              radial-gradient(1000px 500px at 10% -10%, rgba(59,130,246,0.25), transparent 60%),
              radial-gradient(900px 450px at 90% -10%, rgba(245,158,11,0.2), transparent 60%);
  z-index: -1;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 0;
}

.logo {
  font-weight: 800;
  letter-spacing: 0.5px;
  font-size: 20px;
}

.logo span { color: var(--color-accent); }

.nav-links {
  list-style: none;
  display: flex;
  gap: 20px;
}

.nav-links a {
  color: #e5e7eb;
  padding: 8px 12px;
  border-radius: 8px;
}

.nav-links a:hover, .nav-links a:focus {
  background: rgba(255,255,255,0.12);
}

.nav-toggle {
  display: none;
  background: transparent;
  border: 0;
  cursor: pointer;
}

.nav-toggle .bar {
  display: block;
  width: 24px;
  height: 2px;
  background: #fff;
  margin: 6px 0;
  border-radius: 1px;
}

/* ===================== HERO ===================== */
.hero { padding: 92px 0 120px; }

.hero-content {
  padding: 32px 0;
}

.hero h1 {
  font-size: 42px;
  margin: 0 0 8px;
}

.highlight {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tagline { font-size: 20px; color: #cbd5e1; margin: 0 0 16px; opacity: 0.9; }

.hero-description {
  font-size: 16px;
  color: var(--color-muted);
  margin: 0 0 20px;
  max-width: 600px;
  line-height: 1.6;
}

.quick-info {
  list-style: none;
  padding: 0;
  margin: 0 0 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 16px 24px;
  color: #e5e7eb;
}

.quick-info li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.quick-info i {
  color: var(--color-accent);
  width: 16px;
}

.hero-cta { display: flex; gap: 12px; }

.btn {
  display: inline-block;
  padding: 10px 16px;
  border-radius: 10px;
  font-weight: 600;
  transition: transform .2s ease, box-shadow .2s ease, background .2s ease, color .2s ease;
}

.btn-primary { background: var(--color-secondary); color: #fff; box-shadow: 0 0 0 rgba(59,130,246,0.6); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }

.btn-secondary { background: rgba(255,255,255,0.08); color: #fff; border: 1px solid rgba(255,255,255,0.18); }
.btn-secondary:hover { background: rgba(255,255,255,0.22); }

.btn-outline { border: 1.5px solid var(--color-primary); color: var(--color-primary); background: #fff; }
.btn-outline:hover { background: var(--color-primary); color: #fff; }

.btn-accent { background: var(--color-accent); color: #111827; }
.btn-accent:hover { filter: brightness(1.05); transform: translateY(-2px); }

.glow {
  position: relative;
  box-shadow: 0 0 0 rgba(59,130,246,0.5);
}
.glow::after {
  content: '';
  position: absolute; inset: -2px;
  border-radius: 12px;
  background: radial-gradient(600px 80px at 0% 0%, rgba(59,130,246,0.35), transparent 60%);
  filter: blur(14px); z-index: -1; opacity: .6;
}

/* ===================== SECTIONS ===================== */
.section { padding: 72px 0; }
.section-alt { background: var(--color-surface); }

.section-head h2 {
  margin: 0 0 8px;
  font-size: 28px;
  color: var(--color-primary);
}

.section-head p { margin: 0 0 24px; color: var(--color-muted); }

/* ===================== ABOUT ===================== */
.about-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 28px;
}

.about-content {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 24px;
}

.stat-item {
  text-align: center;
  padding: 16px;
  background: var(--color-surface);
  border: 1px solid rgba(148,163,184,0.15);
  border-radius: 10px;
}

.stat-number {
  font-size: 24px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 4px;
}

.stat-label {
  font-size: 12px;
  color: var(--color-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.highlights {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.highlights li {
  background: var(--color-surface);
  border: 1px solid rgba(148,163,184,0.15);
  padding: 12px 14px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.highlights li:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow-sm);
}

.highlights li i {
  color: var(--color-accent);
  width: 16px;
}

/* ===================== SKILLS ===================== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
}

.skill-card {
  background: var(--color-surface);
  border: 1px solid rgba(148,163,184,0.15);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow-sm);
  transition: transform .2s ease, box-shadow .2s ease;
}

.skill-card:hover { transform: translateY(-4px); box-shadow: 0 10px 32px rgba(0,0,0,0.35); }
.skill-icon {
  font-size: 24px;
  margin-bottom: 12px;
  color: var(--color-accent);
}

.skill-card h3 { 
  margin: 0 0 12px; 
  font-size: 16px; 
  color: var(--color-primary); 
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.skill-tag {
  padding: 4px 8px;
  background: rgba(148,163,184,0.1);
  border: 1px solid rgba(148,163,184,0.2);
  border-radius: 12px;
  font-size: 12px;
  color: var(--color-text);
  transition: all 0.2s ease;
}

.skill-tag.primary {
  background: rgba(59,130,246,0.2);
  border-color: rgba(59,130,246,0.4);
  color: var(--color-primary);
  font-weight: 600;
}

.skill-tag:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

/* ===================== PROJECTS ===================== */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.card {
  display: flex;
  flex-direction: column;
  background: var(--color-surface);
  border: 1px solid rgba(148,163,184,0.15);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: transform .2s ease, box-shadow .2s ease;
}

.card:hover { transform: translateY(-6px); box-shadow: 0 16px 44px rgba(0,0,0,0.45); }
.card-body { padding: 18px; }
.card-body h3 { margin: 0 0 8px; color: var(--color-primary); }
.card-body p { margin: 0; color: var(--color-text); }
.card-actions { padding: 16px 18px; border-top: 1px solid rgba(148,163,184,0.1); display: flex; justify-content: flex-end; }

/* ===================== EXPERIENCE (Timeline) ===================== */
.timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 10px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: #e5e7eb;
}

.timeline-item {
  position: relative;
  padding-left: 36px;
  margin-bottom: 24px;
}

.timeline-dot {
  position: absolute;
  left: 4px;
  top: 4px;
  width: 12px;
  height: 12px;
  background: var(--color-secondary);
  border: 2px solid #fff;
  border-radius: 50%;
  box-shadow: var(--shadow-sm);
}

.timeline-content h3 { margin: 0 0 4px; color: var(--color-primary); }
.timeline-content .meta { margin: 0 0 8px; color: var(--color-muted); font-size: 14px; }

/* ===================== EDUCATION ===================== */
.edu-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.edu-card {
  background: var(--color-surface);
  border: 1px solid rgba(148,163,184,0.15);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow-sm);
}

.edu-card h3 { margin: 0 0 6px; color: var(--color-primary); }
.edu-card .meta { margin: 0 0 4px; color: var(--color-muted); }

/* ===================== CERTIFICATIONS ===================== */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
}

.cert-card {
  background: var(--color-surface);
  border: 1px solid rgba(148,163,184,0.15);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.cert-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 32px rgba(0,0,0,0.35);
}

.cert-icon {
  font-size: 24px;
  color: var(--color-accent);
  margin-top: 4px;
}

.cert-content h3 {
  margin: 0 0 8px;
  color: var(--color-primary);
  font-size: 16px;
}

.cert-content p {
  margin: 0 0 12px;
  color: var(--color-muted);
  font-size: 14px;
}

.cert-download {
  font-size: 13px;
  padding: 8px 12px;
}

/* ===================== CONTACT ===================== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.contact-details ul { list-style: none; margin: 0; padding: 0; }
.contact-details li { 
  margin-bottom: 16px; 
  display: flex; 
  align-items: center; 
  gap: 12px;
  padding: 12px;
  background: var(--color-surface);
  border: 1px solid rgba(148,163,184,0.15);
  border-radius: 10px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.contact-details li:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow-sm);
}

.contact-icon {
  color: var(--color-accent);
  font-size: 18px;
  width: 20px;
  text-align: center;
}

.contact-details a {
  color: var(--color-primary);
  transition: color 0.2s ease;
}

.contact-details a:hover {
  color: var(--color-secondary);
}

.contact-form {
  background: var(--color-surface);
  border: 1px solid rgba(148,163,184,0.15);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow-sm);
}

.form-field { display: grid; gap: 6px; margin-bottom: 12px; }
label { font-weight: 600; }
input, textarea {
  padding: 10px 12px;
  border: 1px solid #d1d5db;
  border-radius: 10px;
  font: inherit;
}

input:focus, textarea:focus {
  outline: 2px solid var(--color-secondary);
  border-color: var(--color-secondary);
}

input.error, textarea.error {
  border-color: #ef4444;
  box-shadow: 0 0 0 2px rgba(239, 68, 68, 0.1);
}

.error { color: #ef4444; font-size: 13px; min-height: 16px; }
.form-status { margin-top: 8px; font-size: 14px; }

/* Active navigation styles */
.nav-links a.active {
  background: rgba(59,130,246,0.2);
  color: var(--color-primary);
  border-radius: 8px;
}

/* Mobile nav toggle animation */
.nav-toggle.active .bar:nth-child(1) {
  transform: rotate(-45deg) translate(-5px, 6px);
}

.nav-toggle.active .bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active .bar:nth-child(3) {
  transform: rotate(45deg) translate(-5px, -6px);
}

.nav-toggle .bar {
  transition: all 0.3s ease;
}

/* Back to top button improvements */
.back-to-top {
  transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.2s ease;
  opacity: 0;
  visibility: hidden;
}

.back-to-top:hover {
  transform: translateY(-2px);
}

/* ===================== FOOTER ===================== */
.site-footer { background: #070b18; color: #e5e7eb; }

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 0;
}

.back-to-top {
  display: inline-flex;
  width: 32px;
  height: 32px;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  background: rgba(255,255,255,0.12);
}

.back-to-top:hover { background: rgba(255,255,255,0.22); }

/* ===================== RESPONSIVE ===================== */
@media (max-width: 980px) {
  .skills-grid { grid-template-columns: repeat(3, 1fr); }
  .cards-grid { grid-template-columns: repeat(2, 1fr); }
  .edu-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 720px) {
  .nav-links { display: none; position: absolute; right: 4%; top: 56px; background: #0b1b51; padding: 12px; border-radius: 10px; flex-direction: column; gap: 8px; box-shadow: var(--shadow-md); }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }
  .about-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: repeat(2, 1fr); }
  .cards-grid { grid-template-columns: 1fr; }
  .edu-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 34px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .hero-cta { flex-direction: column; gap: 8px; }
  .hero-cta .btn { text-align: center; }
  .quick-info { justify-content: center; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 28px; }
  .hero { padding: 60px 0 80px; }
  .section { padding: 48px 0; }
  .skills-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr; }
  .skill-card { padding: 14px; }
  .container { width: min(1100px, 95%); }
}

/* ===================== Reveal on scroll ===================== */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity .6s ease, transform .6s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ===================== Modal ===================== */
.modal { position: fixed; inset: 0; display: none; }
.modal.open { display: block; }
.modal-backdrop { position: absolute; inset: 0; background: rgba(0,0,0,0.6); backdrop-filter: blur(4px); }
.modal-dialog { position: relative; margin: 8vh auto; width: min(720px, 92%); background: var(--color-surface); border: 1px solid rgba(148,163,184,0.15); border-radius: 14px; box-shadow: 0 30px 80px rgba(0,0,0,0.5); padding: 20px 20px 16px; color: var(--color-text); }
.modal-close { position: absolute; right: 10px; top: 10px; background: transparent; border: 0; color: var(--color-text); font-size: 24px; cursor: pointer; }
.modal-stack { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.badge { padding: 6px 10px; border-radius: 999px; background: rgba(59,130,246,0.15); color: #bfdbfe; border: 1px solid rgba(59,130,246,0.35); font-size: 12px; }
.modal-links { margin-top: 12px; display: flex; gap: 10px; }