/* ============================================
   color variables
   ============================================ */
:root {
  --cream:          #faf7f2;  
  --gray:           #a8a8a8;  
  --warm-white:     #ffffff;  
  --sage:           #7a9e7e;  
  --sage-light:     #b8d4ba; 
  --sage-pale:      #e8f0e9;  
  --lavender:       #c4b5d4; 
  --lavender-pale:  #ede8f5; 
  --peach:          #e8b89a;  
  --peach-pale:     #faeee6; 
  --brown-soft:     #8b6f5e;  
  --text-dark:      #2d2d2d; 
  --text-mid:       #5f5f5f;  
  --text-light:     #dcd9d9;  
  --border:         #e2dbd0; 
}


/* ============================================
   remove browser default spacing and sizing
   ============================================ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Nunito', sans-serif;
  background: var(--cream);
  color: var(--text-dark);
  line-height: 1.7;
  font-size: 17px;
  overflow-x: hidden; 
}


/* ============================================
   NAV
   Sticky top bar with logo and links.
   ============================================ */
nav {
  position: sticky;     
  top: 0;
  z-index: 100;        
  background: rgba(250, 247, 242, 0.92); 
  backdrop-filter: blur(10px);       
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between; 
  height: 60px;
  width: 100%;
  box-sizing: border-box;
}

.nav-logo {
  font-family: 'Lora', serif;
  font-size: 1rem;
  color: var(--sage);
  font-weight: 600;
}

.nav-links {
  display: flex;
  gap: 2rem;       
  list-style: none; 
}

.nav-links a {
  text-decoration: none;
  color: var(--text-mid);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s; 
}

.nav-links a:hover {
  color: var(--sage);
}


/* ============================================
   opening section.
   ============================================ */
#hero {
  max-width: 100%; 
  margin: 0;       
  min-height: 52vh;        
  display: flex;
  flex-direction: column;    
  align-items: center;      
  justify-content: center;  
  text-align: center;
  padding: 3rem 2rem 4rem;
  position: relative;        
}

#hero::before {
  content: '';          
  position: absolute;
  width: 420px;
  height: 420px;
  background: radial-gradient(circle, rgba(184,212,186,0.35) 0%, transparent 70%);
  top: -50px;
  left: 0;
  border-radius: 50%;
  pointer-events: none;     
}

#hero::after {
  content: '';
  position: absolute;
  width: 420px;
  height: 420px;
  background: radial-gradient(circle, rgba(168, 139, 199, 0.25) 0%, transparent 72%);
  bottom: -40px;
  right: 0;
  border-radius: 50%;
  pointer-events: none;
}

h1.hero-title {
  font-family: 'Lora', serif;
  font-size: clamp(2.4rem, 5vw, 4rem); 
  font-weight: 600;
  line-height: 1.2;
  color: var(--text-dark);
  max-width: 780px;
  animation: fadeUp 0.8s 0.1s ease both;
}

h1.hero-title em {
  font-style: italic;
  color: var(--sage);
}

.hero-subtitle {
  margin-top: 0.8rem;
  font-size: 1.2rem;
  font-weight: 300;
  color: var(--text-mid);
  letter-spacing: 0.04em;
  animation: fadeUp 0.8s 0.2s ease both; 
}

.hero-desc {
  margin-top: 1.8rem;
  max-width: 560px;
  color: var(--text-mid);
  font-size: 1rem;
  animation: fadeUp 0.8s 0.3s ease both; 
}

.hero-pills {
  margin-top: 2rem;
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;          
  justify-content: center;
  animation: fadeUp 0.8s 0.4s ease both; 
}

.pill {
  padding: 0.4rem 1.1rem;
  border-radius: 999px;     
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.03em;
}

.pill-sage  { background: var(--sage-pale);    color: var(--sage); }
.pill-lav   { background: var(--lavender-pale); color: #7c6b9a; }
.pill-peach { background: var(--peach-pale);   color: var(--brown-soft); }

/* ============================================
   SHARED SECTION STYLES
   Reused by every section below the hero.
   ============================================ */

section {
  padding: 2rem 2rem;
  max-width: 900px;
  margin: 0 auto;  
}

.section-label {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.2em;  
  text-transform: uppercase;
  color: var(--sage);
  margin-bottom: 0.6rem;
}

h2.section-title {
  font-family: 'Lora', serif;
  font-size: clamp(1.7rem, 3vw, 2.4rem); 
  font-weight: 600;
  color: var(--text-dark);
  margin-bottom: 1.4rem;
  line-height: 1.25;
}

.section-divider {
  width: 48px;
  height: 3px;
  background: linear-gradient(90deg, var(--sage), var(--lavender)); 
  border-radius: 2px;
  margin-bottom: 2rem;
}

p.body-text {
  color: var(--text-mid);
  margin-bottom: 1.2rem;
  max-width: 720px;
}


/* ============================================
    cards displayed side by side.
   ============================================ */

.motivation-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.2rem;
  margin-top: 2.5rem;
}

.mcard {
  background: var(--warm-white);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.6rem;
  transition: transform 0.2s, box-shadow 0.2s;
}

.mcard:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(0,0,0,0.07);
}

.mcard-icon {
  margin-bottom: 1rem;
}

.mcard-icon svg {
  width: 32px;
  height: 32px;
  stroke-width: 1.5;  
}

.mcard-sage  .mcard-icon svg { stroke: var(--sage); }
.mcard-lav   .mcard-icon svg { stroke: var(--lavender); }
.mcard-peach .mcard-icon svg { stroke: var(--peach); }

.mcard h3 {
  font-family: 'Lora', serif;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-dark);
  margin-bottom: 0.5rem;
}

.mcard p {
  font-size: 0.88rem;
  color: var(--text-mid);
  line-height: 1.6;
}

.mcard-sage  { border-top: 3px solid var(--sage); }
.mcard-lav   { border-top: 3px solid var(--lavender); }
.mcard-peach { border-top: 3px solid var(--peach); }

/* ============================================
   DATA / KNOWLEDGE GRAPH SECTION
   ============================================ */

.kg-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.2rem;
  margin-top: 2rem;
}

@media (max-width: 640px) {
  .kg-grid { grid-template-columns: 1fr; }
}

.kg-card {
  background: var(--warm-white);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.6rem;
  transition: transform 0.2s, box-shadow 0.2s;
  display: flex;
  flex-direction: column;
}

.kg-card-sage  { border-top: 3px solid var(--sage); }
.kg-card-lav   { border-top: 3px solid var(--lavender); }
.kg-card-peach { border-top: 3px solid var(--peach); }
.kg-card-sage-light { border-top: 3px solid var(--sage-light); }

.kg-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(0,0,0,0.07);
}

.kg-card-header {
  display: flex;
  align-items: center;
  gap: 0.6rem;       /* space between icon and heading text */
  margin-bottom: 0.8rem;
}

.kg-card-header svg {
  width: 20px;
  height: 20px;
  stroke-width: 1.5;
  flex-shrink: 0;    /* prevents icon from shrinking if heading wraps */
}

.kg-card-sage  .kg-card-header svg { stroke: var(--sage); }
.kg-card-lav   .kg-card-header svg { stroke: var(--lavender); }
.kg-card-peach .kg-card-header svg { stroke: var(--peach); }
.kg-card-sage-light .kg-card-header svg { stroke: var(--sage-light); }

.kg-card-header h3 {
  font-family: 'Lora', serif;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-dark);
}

.kg-card p {
  font-size: 0.88rem;
  color: var(--text-mid);
  line-height: 1.65;
}

.kg-card ul {
  padding-left: 1.2rem;  
  font-size: 0.88rem;
  color: var(--text-mid);
  line-height: 1.8;
}

.kg-view-btn {
  margin-top: auto;       
  padding-top: 1rem;        
  display: flex;
  align-items: center;
  gap: 0.4rem;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--lavender);
  font-family: 'Nunito', sans-serif;
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  transition: color 0.2s;
  padding-left: 0;
}

.kg-view-btn:hover { color: #7c6b9a; }

.kg-view-btn svg {
  width: 14px;
  height: 14px;
  stroke: currentColor; 
  stroke-width: 2;
}

.kg-callout {
  margin-top: 1.6rem;
  background: linear-gradient(135deg, var(--sage-pale), var(--lavender-pale));
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.6rem 2rem;
}

.kg-callout-label {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  margin-bottom: 0.6rem;
}

.kg-callout-label svg {
  width: 16px;
  height: 16px;
  stroke: var(--sage);
  stroke-width: 1.5;
}

.kg-callout-label span {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--sage);
}

.kg-callout p {
  font-size: 0.92rem;
  color: var(--text-mid);
  line-height: 1.7;
}

/* ============================================
   MODAL: KG structure white box.
   ============================================ */

.modal-overlay {
  position: fixed;         
  inset: 0;             
  background: rgba(0,0,0,0.45);
  z-index: 200;            
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;             
  pointer-events: none;   
  transition: opacity 0.25s ease;
}

.modal-overlay.modal-open {
  opacity: 1;
  pointer-events: all;
}

.modal-box {
  background: var(--warm-white);
  border-radius: 20px;
  padding: 2rem;
  width: 90%;
  max-width: 680px;
  max-height: 90vh;       
  overflow-y: auto;       
  box-shadow: 0 24px 60px rgba(0,0,0,0.15);
  transform: translateY(20px);
  transition: transform 0.25s ease;
}

.modal-overlay.modal-open .modal-box {
  transform: translateY(0);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: flex-end;
}

.modal-title {
  font-family: 'Lora', serif;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-dark);
}

.modal-close {
  position: absolute;
  top: 0.6rem;
  right: 0.6rem;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-light);
  display: flex;
  align-items: center;
  padding: 0.2rem;
  transition: color 0.2s;
}

.modal-close:hover { color: var(--text-dark); }

.modal-close svg {
  width: 20px;
  height: 20px;
  stroke: currentColor;
  stroke-width: 2;
}

.modal-svg-wrap {
  background: var(--warm-white);
  border-radius: 12px;
  padding: 1rem;
  border: 1px solid var(--border);
}

.kg-svg {
  width: 100%;
  height: auto;
}

.kg-svg .node-label {
  font-family: 'Nunito', sans-serif;
  font-size: 11px;
  font-weight: 700;
  fill: var(--text-dark);
  text-anchor: middle;      
}

.kg-svg .node-sublabel {
  font-family: 'Nunito', sans-serif;
  font-size: 9px;
  fill: var(--text-light);
  text-anchor: middle;
}

.kg-svg .edge-label {
  font-family: 'Nunito', sans-serif;
  font-size: 9px;
  fill: var(--text-dark);
  text-anchor: start;
  dominant-baseline: auto;
}

/* ============================================
   SYSTEM ARCHITECTURE SECTION
============================================ */

#architecture {
  padding: 2rem 2rem;
  max-width: 900px;
  margin: 0 auto;
}

.arch-pipeline {
  margin: 48px auto 40px;
  width: 100%;
}

.arch-svg {
  width: 100%;
  height: auto;
  display: block;
}

.arch-svg-label {
  font-family: 'Nunito', sans-serif;
  font-size: 12px;
  font-weight: 600;
  fill: var(--text-dark);
  text-anchor: middle;
  dominant-baseline: middle;
}

.arch-node {
  padding: 10px 32px;
  border-radius: 6px;
  border: 1.5px solid var(--border);
  font-family: 'Nunito', sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-dark);
  text-align: center;
  min-width: 200px;
}

.arch-n-neutral  { background: var(--cream);          border-color: var(--border); }
.arch-n-sage     { background: var(--sage-pale);      border-color: var(--sage); }
.arch-n-lav,
.arch-n-lavender { background: var(--lavender-pale);  border-color: var(--lavender); }
.arch-n-purple   { background: var(--lavender);       border-color: #8f85bb; }
.arch-n-peach    { background: var(--peach-pale);     border-color: var(--peach); }
.arch-n-pink     { background: var(--lavender-pale);  border-color: var(--lavender); }

.arch-arrow {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.arch-arrow-line {
  width: 1.5px;
  height: 24px;
  background: #bbb;
}

.arch-arrow-head {
  width: 0;
  height: 0;
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  border-top: 7px solid #bbb;
}

.arch-fanout {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
}

.arch-fanout-line {
  width: 1.5px;
  height: 20px;
  background: #bbb;
}

.arch-fanout-bar {
  width: 62%;
  height: 1.5px;
  background: #bbb;
}

.arch-fanout-ticks {
  display: flex;
  justify-content: space-between;
  width: 62%;
}

.arch-tick {
  width: 1.5px;
  height: 18px;
  background: #bbb;
}

.arch-fanin {
  flex-direction: column-reverse;
}

.arch-agents {
  display: flex;
  gap: 20px;
  justify-content: center;
  width: 100%;
}

.arch-agents .arch-node {
  min-width: 150px;
  flex: 1;
  max-width: 200px;
}


/* ============================================
   TECHNICAL DETAILS DROPDOWN
============================================ */

.arch-details {
  margin-top: 40px;
  background: linear-gradient(135deg, var(--sage-pale), var(--lavender-pale));
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
}

.arch-details-summary {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 1.2rem 2rem;
  cursor: pointer;
  list-style: none;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--sage);
  user-select: none;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
  font-family: 'Nunito', sans-serif;
}

.arch-details-summary::-webkit-details-marker { display: none; }

.arch-details-summary svg {
  width: 16px; height: 16px;
  stroke: var(--sage);
  stroke-width: 1.5;
  flex-shrink: 0;
}

.arch-details-chevron {
  margin-left: auto;
  transition: transform 0.25s ease;
}

details[open] .arch-details-chevron {
  transform: rotate(180deg);
}

details[open] .arch-details-summary {
  border-bottom: 1px solid var(--border);
}

.arch-details-body {
  padding: 1.4rem 2rem 1.8rem;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.arch-details-intro {
  font-family: 'Nunito', sans-serif;
  font-size: 0.92rem;
  color: var(--text-mid);
  line-height: 1.7;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.arch-details-group h4 {
  font-family: 'Lora', serif;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-dark);
  margin-bottom: 10px;
}

.arch-details-group ul {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.arch-details-group li {
  font-family: 'Nunito', sans-serif;
  font-size: 0.88rem;
  color: var(--text-mid);
  line-height: 1.7;
  padding-left: 14px;
  position: relative;
}

.arch-details-group li::before {
  content: '▪';
  position: absolute;
  left: 0;
  color: var(--sage);
  font-size: 0.8rem;
}

.arch-details-group code {
  font-family: 'Courier New', monospace;
  font-size: 0.82rem;
  background: rgba(255,255,255,0.6);
  color: var(--text-dark);
  padding: 1px 5px;
  border-radius: 4px;
}

/* ============================================
   LEARN MORE SECTION
============================================ */

#learn-more {
  padding: 2rem 2rem;
  max-width: 900px;
  margin: 0 auto;
}

.learn-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.2rem;
  margin-top: 2.5rem;
}

@media (max-width: 600px) {
  .learn-grid { grid-template-columns: 1fr; }
}

.learn-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  padding: 36px 20px;
  background: var(--warm-white);
  border: 1px solid var(--border);
  border-radius: 16px;
  text-decoration: none;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.learn-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(0,0,0,0.07);
}

.learn-card-sage  { border-top: 3px solid var(--sage); }
.learn-card-lav   { border-top: 3px solid var(--lavender); }
.learn-card-peach { border-top: 3px solid var(--peach); }

.learn-icon svg {
  width: 32px;
  height: 32px;
  stroke-width: 1.5;
}

.learn-card-sage  .learn-icon svg { stroke: var(--sage); }
.learn-card-lav   .learn-icon svg { stroke: var(--lavender); }
.learn-card-peach .learn-icon svg { stroke: var(--peach); }

.learn-label {
  font-family: 'Lora', serif;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-dark);
  text-align: center;
}

/* ============================================
   EVALUATION SECTION
============================================ */

/* 4-column stats grid */
.eval-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.2rem;
  margin: 2rem 0;
}

@media (max-width: 700px) {
  .eval-stats { grid-template-columns: repeat(2, 1fr); }
}

.eval-stat {
  background: var(--warm-white);
  border: 1px solid var(--border);
  border-top: 3px solid var(--border);
  border-radius: 16px;
  padding: 1.4rem 1.2rem;
  text-align: center;
}

.eval-stat-sage  { border-top-color: var(--sage); }
.eval-stat-peach { border-top-color: var(--peach); }
.eval-stat-lav   { border-top-color: var(--lavender); }

.eval-stat-number {
  font-family: 'Lora', serif;
  font-size: 2.2rem;
  font-weight: 600;
  color: var(--sage);
  line-height: 1;
  margin-bottom: 0.5rem;
}

.eval-stat-sage  .eval-stat-number { color: var(--sage); }
.eval-stat-peach .eval-stat-number { color: var(--peach); }
.eval-stat-lav   .eval-stat-number { color: var(--lavender); }

.eval-stat-label {
  font-family: 'Nunito', sans-serif;
  font-size: 0.8rem;
  color: var(--text-mid);
  line-height: 1.4;
}

/* Table */
.eval-table-wrap {
  margin: 2rem 0;
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow-x: auto;   /* enables horizontal scroll on mobile */
  -webkit-overflow-scrolling: touch; /* smooth scroll on iOS */
}

.eval-table {
  width: 100%;
  min-width: 420px;   /* prevents table from collapsing below readable width */
  border-collapse: collapse;
  font-family: 'Nunito', sans-serif;
  font-size: 0.9rem;
}

.eval-table thead {
  background: var(--sage-pale);
}

.eval-table th {
  padding: 0.9rem 1.2rem;
  text-align: left;
  font-weight: 700;
  color: var(--text-dark);
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  white-space: nowrap; /* keeps headers on one line */
}

.eval-table td {
  padding: 0.9rem 1.2rem;
  color: var(--text-mid);
  border-top: 1px solid var(--border);
}

.eval-table td:first-child {
  white-space: nowrap; /* keeps test suite names intact */
}

.eval-table tbody tr:hover {
  background: var(--warm-white);
}

/* Accuracy badge */
.eval-acc {
  font-weight: 700;
  color: var(--sage);
}

/* Mobile: tighten up table padding on small screens */
@media (max-width: 500px) {
  .eval-table th,
  .eval-table td {
    padding: 0.7rem 0.85rem;
    font-size: 0.82rem;
  }
}

/* ============================================
   LIMITATIONS & FUTURE WORK SECTION
============================================ */

.lim-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: 2rem;
}

@media (max-width: 700px) {
  .lim-grid { grid-template-columns: 1fr; }
}

.lim-card {
  background: var(--warm-white);
  border: 1px solid var(--border);
  border-top: 3px solid var(--border);
  border-radius: 16px;
  padding: 1.8rem;
}

.lim-card-peach { border-top-color: var(--peach); }
.lim-card-lav   { border-top-color: var(--lavender); }
.lim-card-sage   { border-top-color: var(--sage); }

.lim-card-title {
  font-family: 'Lora', serif;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-dark);
  margin: 0 0 1.2rem 0;
}

.lim-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
}

.lim-list li {
  font-family: 'Nunito', sans-serif;
  font-size: 0.88rem;
  color: var(--text-mid);
  line-height: 1.6;
  padding-left: 0.8rem;
  /* border-left: 2px solid var(--border); */
}

.lim-term {
  font-weight: 700;
  margin-right: 0.2rem;
}

.lim-term-peach { color: var(--peach); }
.lim-term-lav   { color: var(--lavender); }
.lim-term-sage   { color: var(--sage); }

/* ============================================
   ANIMATIONS
   ============================================ */

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes bounce {
  0%, 100% { transform: rotate(45deg) translateY(0); }
  50%       { transform: rotate(45deg) translateY(5px); }
}