:root {
  --navy: #0b132b;
  --teal: #09303a;
  --turquoise: #29d3c3;
  --coral: #ff4b3a; /* brighter coral */
  --white: #f9f9f9;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  scroll-behavior: smooth;
}

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: linear-gradient(180deg, var(--navy) 0%, var(--teal) 100%);
  color: var(--white);
  overflow-x: hidden;
}

/* HEADER */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  display: flex;
  justify-content: center;
  background: rgba(11, 19, 43, 0.85);
  backdrop-filter: blur(8px);
  padding: 1em 0;             /* a bit taller */
  z-index: 100;
  box-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

nav a {
  color: var(--white);
  text-decoration: none;
  margin: 0 1.2em;
  font-weight: 500;
  font-size: 1rem;
  transition: color 0.3s;
}

nav a:hover {
  color: var(--turquoise);
}

/* SECTION LAYOUT */
section {
  padding: 80px 20px;
  text-align: center;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

/* HERO */
#home {
  position: relative;
  height: 88vh;
  min-height: 540px;
  overflow: hidden;
}

.orbit-container {
  position: relative;
  display: inline-block;
  width: min(70vw, 320px);
  aspect-ratio: 1 / 1;
  margin-top: 90px;
}

.orbit {
  position: absolute;
  inset: 0;
  border: 2px solid var(--coral);
  border-radius: 50%;
  animation: spin 22s linear infinite;
  opacity: 0.8;
  z-index: 1;
  transform-origin: 50% 50%;
  will-change: transform;
}

.orbit::before,
.orbit::after {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  background: var(--coral);
  border-radius: 50%;
}

.orbit::before { top: -7px; left: 50%; transform: translateX(-50%); }
.orbit::after  { bottom: -7px; right: 50%; transform: translateX(50%); }

.logo {
  width: 80%;
  height: auto;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 2;
}

h1 {
  font-size: 1.9rem;
  margin-top: 1.4em;
  color: var(--turquoise);
  letter-spacing: 0.02em;
}

.vision {
  margin-top: 0.6em;
  font-style: italic;
  font-size: 1.05rem;
  color: rgba(255,255,255,0.85);
}

/* CONTENT SECTIONS */
#about,
#research,
#contact {
  max-width: 820px;
  margin: auto;
  line-height: 1.7;
  padding: 60px 20px;
}

#about h2,
#research h2,
#contact h2 {
  color: var(--turquoise);
  margin-bottom: 0.7em;
  font-size: 1.7rem;
}

#about p,
#research p,
#contact p {
  font-size: 1rem;
}

a {
  color: var(--coral);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

/* FOOTER */
footer {
  text-align: center;
  padding: 2.5em 0 3em 0;
  margin-top: 3em;
  border-top: 1px solid rgba(255,255,255,0.12);
  color: rgba(255,255,255,0.65);
  font-size: 0.9rem;
}

footer .creator {
  margin-top: 0.4em;
  font-size: 0.85rem;
  opacity: 0.85;
}

footer .footer-links {
  margin-top: 0.5em;
  font-size: 0.85rem;
}

footer .footer-links a {
  color: var(--turquoise);
}
footer .footer-links a:hover {
  text-decoration: underline;
}

/* ANIMATIONS */
@keyframes spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

/* RESPONSIVE */
@media (max-width: 600px) {

  header {
    padding: 1.2em 0;
  }

  nav {
    display: flex;
    flex-wrap: nowrap;
  }

  nav a {
    margin: 0 0.6em;
    font-size: 0.95rem;
    white-space: nowrap;
  }

  /* Hero: make room */
  #home {
    height: auto;         /* instead of forced 88vh */
    padding-top: 120px;   /* space under header */
    padding-bottom: 60px; /* so text never clips */
  }

  .orbit-container {
    width: 200px;
    height: 200px;
    margin-top: 0;        /* remove extra height */
  }

  .logo {
    width: 160px;
  }

  h1 {
    font-size: 1.6rem;
    margin-top: 1.2em;
  }

  .vision {
    font-size: 1rem;
    margin-top: 0.7em;
    padding: 0 20px;
  }

  #about,
  #research,
  #contact {
    padding: 60px 20px;
  }

  #about p,
  #research p,
  #contact p {
    font-size: 1.05rem;
    line-height: 1.65;
  }

  #about h2,
  #research h2,
  #contact h2 {
    font-size: 1.8rem;
  }
}