/* --- Variables --- */
:root {
  --flutter-blue: #02539a;
  --flutter-blue-light: #0373c4;
  --flutter-blue-glow: rgba(2, 83, 154, 0.4);
  --bg-dark: #0d1117;
  --bg-card: rgba(22, 27, 34, 0.7);
  --glass-border: rgba(255, 255, 255, 0.08);
  --text-primary: #e6edf3;
  --text-muted: #8b949e;
  --font: 'Poppins', sans-serif;
  --radius: 12px;
  --radius-lg: 20px;
  --transition: 0.25s ease;
}

/* --- Keyframe Animations --- */
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
@keyframes pulseGlow {
  0%, 100% { box-shadow: 0 4px 20px var(--flutter-blue-glow); }
  50% { box-shadow: 0 4px 28px rgba(2, 83, 154, 0.55); }
}
@keyframes floatBg {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.85; transform: scale(1.02); }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

a {
  color: var(--flutter-blue-light);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover {
  color: #58a6ff;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* --- Header & Nav --- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(13, 17, 23, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--glass-border);
  transition: background var(--transition);
}
.header.anim-header {
  animation: slideDown 0.6s ease-out forwards;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
}

.logo {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text-primary);
}
.logo:hover {
  color: var(--flutter-blue-light);
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 2rem;
}
.nav-links a {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
  position: relative;
  transition: color var(--transition);
}
.nav-links a::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 0;
  height: 2px;
  background: var(--flutter-blue-light);
  transition: width 0.3s ease;
}
.nav-links a:hover {
  color: var(--text-primary);
}
.nav-links a:hover::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  color: var(--text-primary);
}
.nav-toggle span {
  width: 24px;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: var(--transition);
}

/* --- Buttons --- */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  font-family: var(--font);
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition);
}
.btn:hover {
  transform: translateY(-2px);
}
.btn-primary {
  background: var(--flutter-blue);
  color: #fff;
  box-shadow: 0 4px 20px var(--flutter-blue-glow);
}
.btn-primary:hover {
  background: var(--flutter-blue-light);
  box-shadow: 0 6px 28px var(--flutter-blue-glow);
}

/* --- Hero --- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 6rem 0 4rem;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 50% at 50% 0%, var(--flutter-blue-glow) 0%, transparent 50%),
              radial-gradient(ellipse 60% 40% at 80% 60%, rgba(2, 83, 154, 0.15) 0%, transparent 50%);
  pointer-events: none;
  animation: floatBg 8s ease-in-out infinite;
}

.hero-content {
  position: relative;
  text-align: center;
}

.hero-badge {
  display: inline-block;
  padding: 0.35rem 1rem;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--flutter-blue-light);
  background: rgba(2, 83, 154, 0.2);
  border: 1px solid rgba(2, 83, 154, 0.4);
  border-radius: 999px;
  margin-bottom: 1.25rem;
  letter-spacing: 0.02em;
}

.hero-title {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
  background: linear-gradient(180deg, #fff 0%, rgba(230, 237, 243, 0.9) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 520px;
  margin: 0 auto 2rem;
}

.cta {
  margin-top: 0.5rem;
}

/* --- Hero entrance animations --- */
.anim-fade-up {
  opacity: 0;
  animation: fadeUp 0.7s ease-out forwards;
}
.anim-fade-up[data-delay="0"] { animation-delay: 0.1s; }
.anim-fade-up[data-delay="100"] { animation-delay: 0.25s; }
.anim-fade-up[data-delay="200"] { animation-delay: 0.45s; }
.anim-fade-up[data-delay="300"] { animation-delay: 0.65s; }
.anim-pulse-hover {
  animation: pulseGlow 2.5s ease-in-out infinite;
}
.anim-pulse-hover:hover {
  animation: none;
}

/* --- Glassmorphism --- */
.glass {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
}

/* --- Sections --- */
.section {
  padding: 5rem 0;
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  text-align: center;
  margin-bottom: 2.5rem;
  color: var(--text-primary);
}

/* --- About --- */
.about-card {
  padding: 2rem 2.5rem;
  max-width: 720px;
  margin: 0 auto;
}
.about-text {
  font-size: 1.05rem;
  color: var(--text-muted);
}
.about-text strong {
  color: var(--flutter-blue-light);
}

/* --- Tech Stack --- */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 1rem;
  max-width: 720px;
  margin: 0 auto;
}

.tech-card {
  padding: 1.25rem;
  text-align: center;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-primary);
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}
.tech-card:hover {
  transform: translateY(-4px) scale(1.02);
  border-color: rgba(2, 83, 154, 0.3);
  box-shadow: 0 8px 24px rgba(2, 83, 154, 0.15);
}
.tech-card:nth-child(1) { transition-delay: 0s; }
.tech-card:nth-child(2) { transition-delay: 0.03s; }
.tech-card:nth-child(3) { transition-delay: 0.06s; }
.tech-card:nth-child(4) { transition-delay: 0.09s; }
.tech-card:nth-child(5) { transition-delay: 0.12s; }
.tech-card:nth-child(6) { transition-delay: 0.15s; }
.tech-card:nth-child(7) { transition-delay: 0.18s; }
.tech-card:nth-child(8) { transition-delay: 0.21s; }

/* --- Portfolio --- */
.portfolio-sub {
  text-align: center;
  margin: -1.25rem auto 2rem;
  font-size: 0.95rem;
  color: var(--text-muted);
}
.portfolio-sub a {
  color: var(--flutter-blue-light);
  font-weight: 500;
}
.portfolio-sub a:hover {
  text-decoration: underline;
}
.portfolio-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}

.project-card {
  padding: 1.75rem;
  transition: transform 0.35s ease, border-color 0.3s ease, box-shadow 0.35s ease;
}
.project-card:hover {
  transform: translateY(-6px) scale(1.02);
  border-color: rgba(2, 83, 154, 0.3);
  box-shadow: 0 12px 32px rgba(2, 83, 154, 0.12);
}

.project-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}
.project-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* --- Contact --- */
.contact-wrap {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  max-width: 800px;
  margin: 0 auto;
}

.contact-info {
  padding: 2rem;
}
.contact-info p {
  margin-bottom: 1.25rem;
  color: var(--text-muted);
  font-size: 0.95rem;
}
.contact-info p:last-child {
  margin-bottom: 0;
}
.contact-info a {
  color: var(--flutter-blue-light);
}

.contact-form {
  padding: 2rem;
}
.contact-form label {
  display: block;
  font-size: 0.9rem;
  font-weight: 500;
  margin-bottom: 0.35rem;
  color: var(--text-primary);
}
.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 0.65rem 0.9rem;
  margin-bottom: 1rem;
  font-family: var(--font);
  font-size: 0.95rem;
  color: var(--text-primary);
  background: rgba(13, 17, 23, 0.6);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  transition: border-color var(--transition);
}
.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: var(--text-muted);
}
.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--flutter-blue);
}
.contact-form button {
  width: 100%;
  margin-top: 0.25rem;
}

/* --- Footer --- */
.footer {
  padding: 1.5rem 0;
  border-top: 1px solid var(--glass-border);
  text-align: center;
}
.footer p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }
  .nav-links {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: rgba(13, 17, 23, 0.98);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 1.5rem;
    gap: 1rem;
    border-bottom: 1px solid var(--glass-border);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--transition), opacity var(--transition), visibility var(--transition);
  }
  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  .hero {
    padding: 5rem 0 3rem;
  }
  .section {
    padding: 3.5rem 0;
  }
  .contact-wrap {
    grid-template-columns: 1fr;
  }
  .portfolio-grid {
    grid-template-columns: 1fr;
  }
}

/* --- Scroll-in animation --- */
.animate-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.animate-in.in-view {
  opacity: 1;
  transform: translateY(0);
}
.animate-in.in-view.tech-card { transition-duration: 0.5s; }
.animate-in.in-view.project-card { transition-duration: 0.5s; }

@media (max-width: 480px) {
  .container {
    padding: 0 1rem;
  }
  .about-card,
  .contact-info,
  .contact-form {
    padding: 1.5rem;
  }
  .tech-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}