/* ═══════════════════════════════════════════════════════════════
   PORTFOLIO.CSS  –  Main Portfolio Page (portfolio.html) Styles
   Jeeva Sivan Portfolio | Dark Futuristic Developer Theme
   ═══════════════════════════════════════════════════════════════ */

/* ─── Portfolio Body ─────────────────────────────────────────── */
.portfolio-body {
  background: var(--clr-bg-main);
  padding-top: var(--nav-height);
}

/* ─── Fixed Ambient Background ───────────────────────────────── */
.portfolio-body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 100vh;
  background:
    radial-gradient(ellipse 80% 50% at 20% 20%, rgba(59, 130, 246, 0.07) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 80%, rgba(139, 92, 246, 0.05) 0%, transparent 60%),
    radial-gradient(ellipse 50% 30% at 50% 50%, rgba(6, 182, 212, 0.04) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

/* ─── NAVBAR ─────────────────────────────────────────────────── */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  background: rgba(6, 13, 31, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--clr-border);
  transition: background var(--transition-base), box-shadow var(--transition-base);
}

.navbar.scrolled {
  background: rgba(2, 8, 23, 0.95);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.5);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--sp-6);
}

/* ─── Nav Logo ───────────────────────────────────────────────── */
.nav-logo {
  font-family: var(--font-mono);
  font-size: var(--fs-lg);
  font-weight: var(--fw-bold);
  color: var(--clr-text-primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0;
  letter-spacing: -0.02em;
  transition: transform var(--transition-bounce);
}

.nav-logo:hover {
  color: var(--clr-text-primary);
  transform: scale(1.05);
}

.logo-bracket {
  color: var(--clr-cyan);
  text-shadow: var(--glow-text-cyan);
}

.logo-text {
  background: linear-gradient(135deg, var(--clr-blue-bright), var(--clr-purple-bright));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  padding-inline: var(--sp-1);
}

/* ─── Nav Links ──────────────────────────────────────────────── */
.nav-links {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
}

.nav-link {
  position: relative;
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--clr-text-secondary);
  text-decoration: none;
  padding: var(--sp-2) var(--sp-3);
  border-radius: var(--radius-md);
  transition: color var(--transition-base), background var(--transition-base);
  white-space: nowrap;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 70%;
  height: 2px;
  background: linear-gradient(90deg, var(--clr-blue), var(--clr-cyan));
  border-radius: 2px;
  transition: transform var(--transition-base);
}

.nav-link:hover {
  color: var(--clr-text-primary);
  background: rgba(59, 130, 246, 0.07);
}

.nav-link:hover::after {
  transform: translateX(-50%) scaleX(1);
}

.nav-link.active {
  color: var(--clr-blue-bright);
}

.nav-link.active::after {
  transform: translateX(-50%) scaleX(1);
}

/* ─── Nav Active Progress Indicator ─────────────────────────── */
.nav-indicator {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--clr-blue), var(--clr-cyan), var(--clr-purple));
  transition: width var(--transition-base);
  width: 0;
}

/* ─── Hamburger Toggle ───────────────────────────────────────── */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  padding: 4px;
  cursor: pointer;
  border-radius: var(--radius-md);
  transition: background var(--transition-base);
}

.nav-toggle:hover {
  background: rgba(59, 130, 246, 0.1);
}

.hamburger-line {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--clr-text-secondary);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base), background var(--transition-base);
  transform-origin: center;
}

.nav-toggle[aria-expanded="true"] .hamburger-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
  background: var(--clr-blue-bright);
}

.nav-toggle[aria-expanded="true"] .hamburger-line:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.nav-toggle[aria-expanded="true"] .hamburger-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
  background: var(--clr-blue-bright);
}

/* ─── Section Backgrounds (alternating subtle) ───────────────── */
.section {
  position: relative;
  z-index: 1;
}

.section-home          { background: transparent; }
.section-about         { background: rgba(10, 22, 40, 0.3); }
.section-skills        { background: transparent; }
.section-projects      { background: rgba(10, 22, 40, 0.3); }
.section-education     { background: transparent; }
.section-certifications{ background: rgba(10, 22, 40, 0.3); }
.section-internship    { background: transparent; }
.section-softskills    { background: rgba(10, 22, 40, 0.3); }
.section-contact       { background: transparent; }

/* ─── Footer ─────────────────────────────────────────────────── */
.portfolio-footer {
  padding: var(--sp-8) var(--sp-6);
  text-align: center;
  border-top: 1px solid var(--clr-border);
  color: var(--clr-text-muted);
  font-size: var(--fs-sm);
  font-family: var(--font-mono);
  position: relative;
  z-index: 1;
}

/* ─── Back to Top Button ─────────────────────────────────────── */
.back-to-top {
  position: fixed;
  bottom: var(--sp-8);
  right: var(--sp-8);
  width: 44px;
  height: 44px;
  background: rgba(6, 13, 31, 0.9);
  border: 1px solid var(--clr-border-bright);
  border-radius: var(--radius-full);
  color: var(--clr-blue-bright);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 99;
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
  transition: opacity var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
  backdrop-filter: blur(8px);
}

.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.back-to-top:hover {
  box-shadow: var(--glow-blue);
  border-color: var(--clr-blue);
}

/* ─── Responsive Navbar ──────────────────────────────────────── */
@media (max-width: 1023px) {
  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    bottom: 0;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--sp-2);
    background: rgba(2, 8, 23, 0.97);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    transform: translateX(100%);
    transition: transform var(--transition-slow);
    z-index: 999;
    padding: var(--sp-8);
  }

  .nav-links.open {
    transform: translateX(0);
  }

  .nav-link {
    font-size: var(--fs-xl);
    font-weight: var(--fw-semibold);
    padding: var(--sp-4) var(--sp-8);
    width: 100%;
    text-align: center;
    border-radius: var(--radius-lg);
  }

  .nav-toggle {
    display: flex;
  }
}

@media (max-width: 479px) {
  .back-to-top {
    bottom: var(--sp-6);
    right: var(--sp-4);
  }
}