/* ===================================================
   Portfolio – Dark Space Theme (Blue Monochrome)
   Overrides & extensions for Bootstrap 5.3

   Aesthetic: Space / terminal
   Accent: Blue (#9cdcfe)
   =================================================== */

/* --- Design Tokens --- */
:root {
  /* Surfaces – layered blacks */
  --clr-bg: #000000;
  --clr-surface: #0a0a0a;
  --clr-surface-2: #141414;
  --clr-surface-3: #1a1a1a;
  --clr-border: #272727;

  /* Text hierarchy */
  --clr-text: #e7e9ea;
  --clr-text-secondary: #888888;
  --clr-text-muted: #555555;

  /* Accent – blue from solar-system */
  --clr-accent: #9cdcfe;
  --clr-accent-hover: #b4e5ff;
  --clr-accent-dim: #7a7adb;

  /* Semantic */
  --clr-white: #ffffff;

  /* Typography */
  --ff-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --ff-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  /* Motion */
  --transition-fast: 0.15s ease;
  --transition-base: 0.2s ease;
}

/* --- Reset & Global --- */
*,
*::before,
*::after {
  border-color: var(--clr-border);
}

body {
  font-family: var(--ff-body);
  color: var(--clr-text);
  background-color: var(--clr-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--ff-heading);
  color: var(--clr-text);
  font-weight: 700;
}

a {
  color: var(--clr-accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--clr-accent-dim);
}

::selection {
  background: var(--clr-accent);
  color: var(--clr-bg);
}

/* --- Navbar --- */
.navbar {
  background-color: rgba(0, 0, 0, 0.85) !important;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--clr-border);
  padding: 0.6rem 0;
  transition: background-color var(--transition-base);
}

.navbar-brand {
  font-family: var(--ff-heading);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--clr-text) !important;
  letter-spacing: -0.01em;
}

.nav-link {
  color: var(--clr-text-secondary) !important;
  font-weight: 500;
  font-size: 0.9rem;
  padding: 0.5rem 1rem !important;
  border-radius: 9999px;
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-link:hover,
.nav-link:focus {
  color: var(--clr-text) !important;
  background-color: var(--clr-surface-2);
}

.nav-link.active {
  color: var(--clr-text) !important;
  font-weight: 700;
  background-color: transparent !important;
  position: relative;
}

/* Underline indicator for active link */
.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -0.6rem;
  left: 50%;
  transform: translateX(-50%);
  width: 32px;
  height: 3px;
  background-color: var(--clr-white);
  border-radius: 9999px;
}

.navbar-toggler {
  border-color: var(--clr-border);
}

.navbar-toggler-icon {
  filter: invert(1);
}

/* --- Hero Section --- */
.hero-section {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--clr-bg);
  color: var(--clr-text);
  text-align: center;
  position: relative;
  overflow: hidden;
}

/* Very faint radial glow */
.hero-section::before {
  content: '';
  position: absolute;
  width: 700px;
  height: 700px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.025) 0%, transparent 70%);
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
}

.hero-section h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  color: var(--clr-text);
  margin-bottom: 1rem;
  position: relative;
  z-index: 1;
  letter-spacing: -0.03em;
}

.hero-section .lead {
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  color: var(--clr-text-secondary);
  max-width: 520px;
  margin: 0 auto 2.5rem;
  position: relative;
  z-index: 1;
  line-height: 1.5;
}

/* --- Buttons --- */
/* Primary CTA: inverted (white on black = stands out) */
.btn-cta {
  background-color: var(--clr-accent);
  color: var(--clr-bg);
  border: none;
  padding: 0.75rem 2rem;
  font-size: 0.95rem;
  font-weight: 700;
  border-radius: 9999px;
  transition: background-color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
  position: relative;
  z-index: 1;
}

.btn-cta:hover,
.btn-cta:focus-visible {
  background-color: var(--clr-accent-hover);
  color: var(--clr-bg);
  transform: scale(1.03);
  box-shadow: 0 0 30px rgba(156, 220, 254, 0.2);
}

.btn-cta:active {
  transform: scale(0.98);
  box-shadow: none;
}

/* Outline variant */
.btn-outline-dark {
  color: var(--clr-text);
  border: 1px solid var(--clr-border);
  background: transparent;
  border-radius: 9999px;
  font-weight: 600;
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.btn-outline-dark:hover {
  background-color: var(--clr-surface-2);
  border-color: var(--clr-text-secondary);
  color: var(--clr-text);
}

/* --- Section Layout --- */
.section-heading {
  font-size: 1.75rem;
  font-weight: 800;
  margin-bottom: 0.25rem;
  letter-spacing: -0.02em;
}

.section-subheading {
  color: var(--clr-text-secondary);
  font-size: 0.95rem;
  margin-bottom: 2.5rem;
}

section.py-5 {
  border-bottom: 1px solid var(--clr-border);
}

/* --- About Page --- */
.about-img {
  width: 100%;
  max-width: 280px;
  border-radius: 50%;
  border: 3px solid var(--clr-border);
  object-fit: cover;
}

.skill-category {
  margin-bottom: 1.5rem;
}

.skill-category h5 {
  font-family: var(--ff-body);
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--clr-text-secondary);
  margin-bottom: 0.75rem;
}

.progress {
  height: 6px;
  border-radius: 9999px;
  background-color: var(--clr-surface-3);
  margin-bottom: 0.6rem;
  overflow: hidden;
}

.progress-bar {
  background-color: var(--clr-accent);
  border-radius: 9999px;
  transition: width 0.8s ease-out;
}

.skill-label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--clr-text);
  margin-bottom: 0.15rem;
}

/* --- Experience Timeline --- */
.timeline {
  position: relative;
  padding: 2rem 0;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--clr-border);
  transform: translateX(-50%);
}

.timeline-item {
  position: relative;
  width: 50%;
  padding: 1.5rem 2.5rem;
}

.timeline-item:nth-child(odd) {
  left: 0;
  text-align: right;
  padding-right: 3rem;
}

.timeline-item:nth-child(even) {
  left: 50%;
  padding-left: 3rem;
}

.timeline-item::after {
  content: '';
  position: absolute;
  width: 12px;
  height: 12px;
  background: var(--clr-accent);
  border: 2px solid var(--clr-bg);
  border-radius: 50%;
  top: 2rem;
  z-index: 1;
  box-shadow: 0 0 0 4px var(--clr-surface);
}

.timeline-item:nth-child(odd)::after {
  right: -6px;
}

.timeline-item:nth-child(even)::after {
  left: -6px;
}

.timeline-card {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: 16px;
  padding: 1.25rem;
  transition: border-color var(--transition-base), background-color var(--transition-base);
}

.timeline-card:hover {
  border-color: var(--clr-text-secondary);
  background-color: var(--clr-surface-2);
}

.timeline-card h4 {
  font-family: var(--ff-body);
  font-size: 1rem;
  font-weight: 700;
  color: var(--clr-text);
  margin-bottom: 0.2rem;
}

.timeline-card .company {
  color: var(--clr-accent);
  font-weight: 600;
  font-size: 0.9rem;
}

.timeline-card .date {
  font-size: 0.8rem;
  color: var(--clr-text-muted);
  margin-bottom: 0.6rem;
  display: block;
}

.timeline-card ul {
  padding-left: 1.1rem;
  margin-bottom: 0;
}

.timeline-card ul li {
  font-size: 0.88rem;
  margin-bottom: 0.25rem;
  color: var(--clr-text-secondary);
}

/* Mobile timeline */
@media (max-width: 767.98px) {
  .timeline::before {
    left: 16px;
  }

  .timeline-item {
    width: 100%;
    left: 0 !important;
    text-align: left !important;
    padding-left: 3rem !important;
    padding-right: 1rem !important;
  }

  .timeline-item::after {
    left: 10px !important;
    right: auto !important;
  }
}

/* --- Project Cards --- */
.project-card {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: 16px;
  overflow: hidden;
  transition: border-color var(--transition-base), background-color var(--transition-base), transform var(--transition-base);
  height: 100%;
}

.project-card:hover {
  border-color: var(--clr-text-secondary);
  background-color: var(--clr-surface-2);
  transform: translateY(-2px);
}

.project-card .card-img-top {
  height: 180px;
  object-fit: cover;
  background-color: var(--clr-surface-3);
}

.project-card .card-body {
  padding: 1.25rem;
}

.project-card .card-title {
  font-family: var(--ff-body);
  font-weight: 700;
  font-size: 1rem;
  color: var(--clr-text);
  margin-bottom: 0.4rem;
}

.project-card .card-text {
  font-size: 0.88rem;
  color: var(--clr-text-secondary);
  margin-bottom: 0.75rem;
  line-height: 1.45;
}

.project-card .badge {
  font-weight: 600;
  font-size: 0.72rem;
  padding: 0.3em 0.7em;
  margin-right: 0.25rem;
  margin-bottom: 0.25rem;
  border-radius: 9999px;
}

.project-card .badge.bg-accent {
  background-color: var(--clr-surface-3) !important;
  color: var(--clr-text) !important;
  border: 1px solid var(--clr-border);
}

.project-card .badge.bg-secondary {
  background-color: var(--clr-surface-3) !important;
  color: var(--clr-text-secondary) !important;
}

.project-card .card-footer {
  background: transparent;
  border-top: 1px solid var(--clr-border);
  padding: 0.85rem 1.25rem;
}

.project-card .card-footer a {
  font-weight: 600;
  font-size: 0.85rem;
  text-decoration: none;
}

.project-card .card-footer a:hover {
  text-decoration: underline;
}

/* --- Contact Form --- */
.contact-form .form-control {
  border-radius: 8px;
  border: 1px solid var(--clr-border);
  background-color: var(--clr-surface);
  color: var(--clr-text);
  padding: 0.75rem 1rem;
  font-size: 0.95rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.contact-form .form-control::placeholder {
  color: var(--clr-text-muted);
}

.contact-form .form-control:focus {
  border-color: var(--clr-accent);
  background-color: var(--clr-surface);
  color: var(--clr-text);
  box-shadow: 0 0 0 3px rgba(156, 220, 254, 0.12);
}

.contact-form .form-label {
  font-weight: 600;
  font-size: 0.88rem;
  color: var(--clr-text);
}

.social-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--clr-border);
  background-color: transparent;
  color: var(--clr-text-secondary);
  font-size: 1.15rem;
  margin: 0 0.4rem;
  transition: color var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast);
}

.social-links a:hover {
  color: var(--clr-accent);
  border-color: var(--clr-accent);
  background-color: rgba(156, 220, 254, 0.06);
}

/* --- Footer --- */
.site-footer {
  background-color: var(--clr-bg);
  border-top: 1px solid var(--clr-border);
  color: var(--clr-text-muted);
  padding: 1.5rem 0;
  font-size: 0.82rem;
}

.site-footer a {
  color: var(--clr-text-secondary);
}

.site-footer a:hover {
  color: var(--clr-white);
}

/* --- Back to Top Button --- */
#backToTop {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: var(--clr-surface-2);
  border: 1px solid var(--clr-border);
  color: var(--clr-text-secondary);
  font-size: 1rem;
  display: none;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: color var(--transition-fast), border-color var(--transition-fast), opacity var(--transition-base);
  z-index: 1050;
  opacity: 0;
}

#backToTop.show {
  display: flex;
  opacity: 1;
}

#backToTop:hover {
  color: var(--clr-accent);
  border-color: var(--clr-accent);
}

/* --- Utility --- */
.text-accent {
  color: var(--clr-accent) !important;
}

.bg-accent {
  background-color: var(--clr-surface-3) !important;
}

.text-muted {
  color: var(--clr-text-secondary) !important;
}

/* Placeholder image fill */
.img-placeholder {
  width: 100%;
  height: 180px;
  background: var(--clr-surface-3);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--clr-text-muted);
  font-size: 0.85rem;
}

/* --- Focus Visible (Accessibility) --- */
:focus-visible {
  outline: 2px solid var(--clr-accent);
  outline-offset: 2px;
}

button:focus-visible,
a:focus-visible {
  outline: 2px solid var(--clr-accent);
  outline-offset: 2px;
}

/* --- Scrollbar --- */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--clr-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--clr-surface-3);
  border-radius: 9999px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--clr-text-muted);
}