/* Formal Math Reasoning - Custom Styles */

/* =============================================
   CSS Variables
   ============================================= */
:root {
  --accent-color: #A62639;
  --accent-hover: #8C1F2F;
  --accent-light: rgba(166, 38, 57, 0.08);
  --bg-off-white: #FAFAFA;
  --card-gradient-start: #F8F6F3;
  --card-gradient-end: #F5F7FA;
  --text-primary: #2D3748;
  --text-secondary: #718096;
  --border-color: #E2E8F0;
  --hero-gradient-1: #1a1a2e;
  --hero-gradient-2: #16213e;
  --hero-gradient-3: #0f3460;
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

/* =============================================
   Global Font Override
   ============================================= */
body,
.navbar,
.footer,
h1, h2, h3, h4, h5, h6,
p, a, span, div,
.btn,
input, textarea, select {
  font-family: var(--font-family) !important;
}

/* Override Beautiful Jekyll default fonts */
body {
  font-family: var(--font-family) !important;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-family) !important;
  font-weight: 600;
}

.navbar-brand,
.nav-link {
  font-family: var(--font-family) !important;
}

/* =============================================
   Hero Section
   ============================================= */
.hero-section {
  background: linear-gradient(135deg, var(--hero-gradient-1) 0%, var(--hero-gradient-2) 50%, var(--hero-gradient-3) 100%);
  min-height: 85vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: #ffffff;
  padding: 4rem 1.5rem 4rem;
  position: relative;
  overflow: hidden;
  /* Extend background behind navbar */
  margin-top: -56px;
  padding-top: calc(56px + 4rem);
}

/* Particle Network Canvas - contained within hero */
.particle-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
}

.hero-content {
  max-width: 800px;
  margin: 0 auto;
  position: relative;
  z-index: 2;
}

.hero-title {
  font-size: 3rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 1rem;
  line-height: 1.1;
}

.hero-subtitle {
  font-size: 1.2rem;
  font-weight: 400;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto 2rem;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.hero-cta {
  display: inline-block;
  background: var(--accent-color);
  color: white !important;
  padding: 0.875rem 2rem;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: background 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 4px 15px rgba(166, 38, 57, 0.3);
}

.hero-cta:hover {
  background: var(--accent-hover);
  transform: translateY(-3px) scale(1.02);
  text-decoration: none;
  color: white !important;
  box-shadow: 0 8px 25px rgba(166, 38, 57, 0.4);
}

.hero-cta:active {
  transform: translateY(-1px) scale(0.98);
  box-shadow: 0 2px 10px rgba(166, 38, 57, 0.3);
}

.hero-cta-secondary {
  background: transparent;
  border: 2px solid rgba(255,255,255,0.4);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.hero-cta-secondary:hover {
  background: rgba(255,255,255,0.15);
  border-color: rgba(255,255,255,0.8);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
  transform: translateY(-3px) scale(1.02);
}

.hero-cta-secondary:active {
  transform: translateY(-1px) scale(0.98);
}

/* Responsive hero */
@media (min-width: 768px) {
  .hero-title {
    font-size: 3.5rem;
  }

  .hero-subtitle {
    font-size: 1.3rem;
  }
}

@media (min-width: 992px) {
  .hero-section {
    min-height: 85vh;
  }

  .hero-title {
    font-size: 4rem;
  }
}

/* =============================================
   Section Styling
   ============================================= */
.section {
  padding: 4rem 0;
}

.section-alt {
  background: #ffffff;
}

.section-title {
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1.05rem;
  margin-bottom: 2.5rem;
  font-weight: 400;
}

/* =============================================
   About Section
   ============================================= */
.about-section {
  padding: 3rem 0;
  background: #ffffff;
}

.about-content {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.about-text {
  font-size: 1.125rem;
  line-height: 1.8;
  color: var(--text-secondary);
  font-weight: 400;
}

.about-text strong {
  color: var(--text-primary);
  font-weight: 600;
}

/* =============================================
   Publications Grid
   ============================================= */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(1, 1fr);
  gap: 1.5rem;
  padding: 1rem 0;
}

@media (min-width: 768px) {
  .projects-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .projects-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* =============================================
   Project Card - Animated Hover Effect
   ============================================= */
.project-card {
  background: linear-gradient(145deg, var(--card-gradient-start) 0%, var(--card-gradient-end) 100%);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 1.75rem;
  position: relative;
  overflow: hidden;
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
  display: flex;
  flex-direction: column;
  height: 100%;
  z-index: 1;
}

/* Animated color sweep overlay */
.project-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, var(--accent-color) 0%, #c23a4f 50%, var(--accent-hover) 100%);
  transform: translateX(-101%);
  transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: -1;
  border-radius: 15px;
}

/* Accent bar on left */
.project-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--accent-color);
  transition: opacity 0.3s ease;
  z-index: 2;
}

.project-card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 20px 40px rgba(166, 38, 57, 0.2), 0 0 0 2px var(--accent-color);
  border-color: transparent;
}

.project-card:active {
  transform: translateY(-4px) scale(1.01);
}

.project-card:hover::before {
  transform: translateX(0);
}

.project-card:hover::after {
  opacity: 0;
}

/* Card content transitions for hover */
.project-card .venue-badge,
.project-card .card-title,
.project-card .card-description,
.project-card .card-link {
  position: relative;
  z-index: 2;
  transition: color 0.3s ease 0.1s;
}

.project-card:hover .venue-badge {
  background: rgba(255, 255, 255, 0.2);
  color: #ffffff;
}

.project-card:hover .card-title {
  color: #ffffff;
}

.project-card:hover .card-description {
  color: rgba(255, 255, 255, 0.9);
}

.project-card:hover .card-link {
  color: #ffffff;
}

.venue-badge {
  display: inline-block;
  background: var(--accent-light);
  color: var(--accent-color);
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.3rem 0.75rem;
  border-radius: 9999px;
  margin-bottom: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  width: fit-content;
  transition: background 0.3s ease, color 0.3s ease;
}

.card-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.card-description {
  font-size: 0.925rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 1.25rem;
  flex-grow: 1;
  font-weight: 400;
}

.card-links {
  display: flex;
  gap: 1.25rem;
  margin-top: auto;
  position: relative;
  z-index: 2;
}

.card-link {
  color: var(--accent-color);
  font-weight: 600;
  text-decoration: none;
  font-size: 0.85rem;
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.4rem 0.6rem;
  border-radius: 6px;
  background: transparent;
  transition: color 0.3s ease, background 0.3s ease, transform 0.2s ease;
}

.card-link:hover {
  text-decoration: none;
  background: var(--accent-light);
  transform: translateX(3px);
}

.project-card:hover .card-link {
  background: rgba(255, 255, 255, 0.15);
}

.project-card:hover .card-link:hover {
  background: rgba(255, 255, 255, 0.3);
  transform: translateX(4px);
}

/* =============================================
   Tools Section
   ============================================= */
.tools-section {
  background: var(--bg-off-white);
}

.tool-card {
  background: #FFFFFF;
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 1.5rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  margin-bottom: 1rem;
  transition: box-shadow 0.3s ease, border-color 0.3s ease, transform 0.3s ease;
  position: relative;
  overflow: hidden;
}

/* Subtle accent line on left */
.tool-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--accent-color);
  transform: scaleY(0);
  transition: transform 0.3s ease;
  transform-origin: bottom;
}

.tool-card:hover {
  box-shadow: 0 12px 32px rgba(0,0,0,0.12);
  border-color: var(--accent-color);
  transform: translateY(-4px);
}

.tool-card:hover::before {
  transform: scaleY(1);
}

.tool-card:active {
  transform: translateY(-2px);
}

.tool-icon {
  font-size: 2rem;
  flex-shrink: 0;
}

.tool-info {
  flex: 1;
}

.tool-name {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
  letter-spacing: -0.01em;
}

.tool-description {
  color: var(--text-secondary);
  font-size: 0.925rem;
  margin: 0;
  font-weight: 400;
}

.tool-cta {
  background: var(--accent-color);
  color: white !important;
  padding: 0.625rem 1.25rem;
  border-radius: 8px;
  text-decoration: none;
  white-space: nowrap;
  font-weight: 500;
  font-size: 0.85rem;
  transition: background 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease, gap 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  box-shadow: 0 4px 12px rgba(166, 38, 57, 0.25);
}

.tool-cta::after {
  content: '→';
  transition: transform 0.2s ease;
}

.tool-cta:hover {
  background: var(--accent-hover);
  transform: translateY(-3px);
  text-decoration: none;
  color: white !important;
  box-shadow: 0 8px 20px rgba(166, 38, 57, 0.35);
  gap: 0.75rem;
}

.tool-cta:hover::after {
  transform: translateX(3px);
}

.tool-cta:active {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(166, 38, 57, 0.25);
}

/* Responsive tool cards */
@media (max-width: 640px) {
  .tool-card {
    flex-direction: column;
    text-align: center;
    gap: 1rem;
  }

  .tool-info {
    text-align: center;
  }
}

/* =============================================
   Layout Utilities
   ============================================= */
.container-narrow {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Override default page margins for landing page */
body.landing-page .intro-header {
  display: none;
}

body.landing-page main {
  margin-top: 0;
}

/* =============================================
   Navbar Enhancements - Transparent to Solid
   ============================================= */
.navbar.navbar-custom {
  font-weight: 500;
  transition: background-color 0.3s ease, backdrop-filter 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

/* Default transparent state for landing page (before JS adds classes) */
body.landing-page .navbar.navbar-custom {
  background-color: transparent !important;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  border-bottom: none !important;
  box-shadow: none !important;
}

body.landing-page .navbar.navbar-custom .navbar-brand,
body.landing-page .navbar.navbar-custom .nav-link {
  color: #ffffff !important;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

/* Hover handled in enhanced nav-link styles below */

body.landing-page .navbar.navbar-custom .navbar-toggler-icon {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(255, 255, 255, 0.95)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e") !important;
}

/* Transparent navbar state (same as default, for JS toggle) */
body.landing-page .navbar.navbar-custom.navbar-transparent {
  background-color: transparent !important;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  border-bottom: none !important;
  box-shadow: none !important;
}

/* Force remove navbar-light styles on transparent */
body.landing-page .navbar.navbar-custom.navbar-transparent.navbar-light .navbar-brand,
body.landing-page .navbar.navbar-custom.navbar-transparent.navbar-light .nav-link,
body.landing-page .navbar.navbar-custom.navbar-transparent .navbar-brand,
body.landing-page .navbar.navbar-custom.navbar-transparent .nav-link {
  color: #ffffff !important;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

/* Transparent hover handled in enhanced nav-link styles below */

/* Hamburger icon white on transparent */
body.landing-page .navbar.navbar-custom.navbar-transparent .navbar-toggler-icon {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(255, 255, 255, 0.95)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e") !important;
}

/* Scrolled state - solid white */
body.landing-page .navbar.navbar-custom.navbar-scrolled {
  background-color: #ffffff !important;
  backdrop-filter: none !important;
  -webkit-backdrop-filter: none !important;
  border-bottom: 1px solid var(--border-color) !important;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08) !important;
}

body.landing-page .navbar.navbar-custom.navbar-scrolled .navbar-brand,
body.landing-page .navbar.navbar-custom.navbar-scrolled .nav-link {
  color: var(--text-primary) !important;
  text-shadow: none !important;
}

/* Scrolled hover handled in enhanced nav-link styles below */

/* Hamburger icon dark on scrolled */
body.landing-page .navbar.navbar-custom.navbar-scrolled .navbar-toggler-icon {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(45, 55, 72, 0.95)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e") !important;
}

.navbar-brand {
  font-weight: 600;
  letter-spacing: -0.01em;
  transition: color 0.3s ease, transform 0.2s ease;
}

.navbar-brand:hover {
  transform: scale(1.02);
}

/* Nav link base styles with animated underline */
.navbar-custom .nav-link {
  font-weight: 500;
  font-size: 0.925rem;
  transition: color 0.3s ease, transform 0.2s ease;
  position: relative;
  padding-bottom: 0.5rem;
}

/* Animated underline effect */
.navbar-custom .nav-link::after {
  content: '';
  position: absolute;
  bottom: 0.25rem;
  left: 50%;
  width: 0;
  height: 2px;
  background: currentColor;
  transition: width 0.3s ease, left 0.3s ease;
  border-radius: 1px;
}

.navbar-custom .nav-link:hover::after,
.navbar-custom .nav-link:focus::after {
  width: 80%;
  left: 10%;
}

/* Landing page transparent state - white underline */
body.landing-page .navbar.navbar-custom .nav-link::after {
  background: rgba(255, 255, 255, 0.8);
}

body.landing-page .navbar.navbar-custom .nav-link:hover,
body.landing-page .navbar.navbar-custom .nav-link:focus {
  color: #ffffff !important;
  transform: translateY(-1px);
}

/* Landing page scrolled state - accent underline */
body.landing-page .navbar.navbar-custom.navbar-scrolled .nav-link::after {
  background: var(--accent-color);
}

body.landing-page .navbar.navbar-custom.navbar-scrolled .nav-link:hover,
body.landing-page .navbar.navbar-custom.navbar-scrolled .nav-link:focus {
  color: var(--accent-color) !important;
  transform: translateY(-1px);
}

/* =============================================
   Footer Adjustments
   ============================================= */
footer.footer {
  background: var(--hero-gradient-1);
}

footer.footer a {
  font-weight: 500;
}

/* =============================================
   Smooth Scroll
   ============================================= */
html {
  scroll-behavior: smooth;
}

/* Offset for anchor links with fixed navbar */
:target {
  scroll-margin-top: 80px;
}

/* =============================================
   Selection Color
   ============================================= */
::selection {
  background: var(--accent-color);
  color: white;
}

::-moz-selection {
  background: var(--accent-color);
  color: white;
}