/* ================================================================
   Beyond the Clouds — BAH 2026
   Academic Research Proposal Stylesheet
   Aesthetic: IEEE / ISPRS journal paper rendered on screen
   Fonts: Crimson Pro (body serif), JetBrains Mono (code/eq)
   ================================================================ */

@import url('https://fonts.googleapis.com/css2?family=Crimson+Pro:ital,wght@0,400;0,600;0,700;1,400;1,600&family=JetBrains+Mono:wght@400;600&family=Inter:wght@400;500;600;700&display=swap');

/* ─── Variables ─────────────────────────────────────── */
:root {
  --paper:       #FAFAF8;
  --paper-tint:  #F3F1EC;
  --ink:         #1A1A1A;
  --ink-body:    #2E2E2E;
  --ink-muted:   #5C5C5C;
  --ink-caption: #7A7A7A;
  --isro-blue:   #003087;
  --isro-blue2:  #1A4AAA;
  --isro-orange: #C85000;
  --green:       #1A6B35;
  --rule:        #C4BDB0;
  --border:      #DDD9D0;
  --highlight:   #FFF8EA;
  --code-bg:     #EFECE6;
  --f-serif:     'Crimson Pro', Georgia, serif;
  --f-mono:      'JetBrains Mono', 'Courier New', monospace;
  --f-sans:      'Inter', system-ui, sans-serif;
  --w-text:      860px;
  --w-wide:      1060px;
}

/* ─── Reset ─────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 17px; }
body {
  background: var(--paper);
  color: var(--ink-body);
  font-family: var(--f-serif);
  line-height: 1.75;
  overflow-x: hidden;
}
::selection { background: rgba(0,48,135,0.12); }
a { color: var(--isro-blue); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ─── Progress bar ──────────────────────────────────── */
#progress {
  position: fixed; top: 0; left: 0; height: 2px; z-index: 9999;
  background: linear-gradient(90deg, var(--isro-blue), var(--isro-orange));
  width: 0%; transition: width 0.1s linear; pointer-events: none;
}

/* ─── Navigation ────────────────────────────────────── */
nav {
  position: fixed; inset: 0 0 auto;
  height: 52px; z-index: 200;
  background: rgba(250,250,248,0.97);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--rule);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 2rem;
}
.nav-left {
  display: flex; align-items: center; gap: 10px;
  font-family: var(--f-sans); font-size: 0.72rem; font-weight: 600;
  color: var(--isro-blue); letter-spacing: 0.04em;
}
.nav-tag {
  background: var(--isro-blue); color: #fff;
  font-size: 0.58rem; font-weight: 700;
  padding: 2px 6px; border-radius: 2px; letter-spacing: 0.1em;
}
nav ul {
  list-style: none; display: flex; gap: 1.5rem;
  font-family: var(--f-sans); font-size: 0.7rem; color: var(--ink-muted);
}
nav ul a { color: var(--ink-muted); transition: color 0.18s; }
nav ul a:hover, nav ul a.active { color: var(--isro-blue); text-decoration: none; }
.nav-pdf {
  font-family: var(--f-sans); font-size: 0.68rem; font-weight: 600;
  border: 1px solid var(--isro-blue); color: var(--isro-blue);
  padding: 5px 14px; border-radius: 3px; cursor: pointer;
  background: transparent; transition: background 0.18s, color 0.18s;
  letter-spacing: 0.04em;
}
.nav-pdf:hover { background: var(--isro-blue); color: #fff; }

/* ─── Hero ──────────────────────────────────────────── */
#hero {
  max-width: var(--w-text);
  margin: 0 auto;
  padding: 100px 2rem 56px;
  text-align: center;
}
.paper-rule { border: none; border-top: 1.5px solid var(--ink); margin: 1rem 0; }
.paper-rule.thin { border-top-width: 1px; }

.conf-line {
  font-family: var(--f-sans); font-size: 0.68rem; font-weight: 600;
  letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--isro-orange); margin: 1rem 0 1.4rem;
}

h1.title {
  font-family: var(--f-serif);
  font-size: clamp(1.45rem, 3vw, 2.1rem);
  font-weight: 700; line-height: 1.25;
  color: var(--ink); letter-spacing: -0.01em;
  margin-bottom: 0.5rem;
}

.subtitle {
  font-family: var(--f-serif);
  font-size: 1.05rem; font-style: italic;
  color: var(--ink-muted); margin-bottom: 1.8rem;
}

.authors {
  font-family: var(--f-sans); font-size: 0.9rem;
  display: flex; flex-wrap: wrap; justify-content: center; gap: 0.5rem 2rem;
  margin-bottom: 0.4rem;
}
.author { color: var(--isro-blue); font-weight: 500; }

.affil {
  font-family: var(--f-sans); font-size: 0.76rem;
  color: var(--ink-muted); font-style: italic; margin-bottom: 1.6rem;
}

.kw-line {
  font-family: var(--f-sans); font-size: 0.8rem;
  color: var(--ink-muted); margin: 1rem 0 0;
}
.kw-line strong { color: var(--ink); font-weight: 600; }

/* Abstract */
.abstract {
  text-align: left;
  margin: 1.8rem 0 0;
  padding: 1.4rem 1.8rem;
  background: var(--paper-tint);
  border: 1px solid var(--border);
  border-left: 3px solid var(--isro-blue);
}
.abstract-head {
  font-family: var(--f-sans); font-size: 0.65rem; font-weight: 700;
  letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--isro-blue); margin-bottom: 0.7rem;
}
.abstract p {
  font-size: 0.95rem; line-height: 1.78; color: var(--ink-body);
}
.abstract p strong { color: var(--ink); }

/* ─── Section Layout ────────────────────────────────── */
.sec-wrap {
  max-width: var(--w-text);
  margin: 0 auto;
  padding: 52px 2rem;
}
.sec-wrap.wide { max-width: var(--w-wide); }
section.tint { background: var(--paper-tint); }

.sec-label {
  font-family: var(--f-sans); font-size: 0.62rem; font-weight: 700;
  letter-spacing: 0.15em; text-transform: uppercase;
  color: var(--isro-orange); margin-bottom: 0.25rem;
}
h2.sec-h {
  font-family: var(--f-serif);
  font-size: 1.55rem; font-weight: 700;
  color: var(--ink);
  border-bottom: 1.5px solid var(--isro-blue);
  display: inline-block; padding-bottom: 0.3rem;
  margin-bottom: 1.4rem;
}
h3.sub-h {
  font-family: var(--f-serif);
  font-size: 1.08rem; font-weight: 600;
  color: var(--ink); margin: 1.8rem 0 0.6rem;
}
h3.sub-h em { color: var(--isro-blue); font-style: normal; }

p.body { font-size: 0.97rem; line-height: 1.78; color: var(--ink-body); margin-bottom: 0.9rem; }
p.body strong { color: var(--ink); }

/* Section rule */
hr.sr { border: none; border-top: 1px solid var(--rule); max-width: var(--w-text); margin: 0 auto; }

/* ─── Info / Note Boxes ─────────────────────────────── */
.box {
  padding: 1rem 1.4rem; border-radius: 2px;
  margin: 1.4rem 0; font-size: 0.93rem; line-height: 1.7;
}
.box-label {
  font-family: var(--f-sans); font-size: 0.62rem; font-weight: 700;
  letter-spacing: 0.1em; text-transform: uppercase;
  display: block; margin-bottom: 0.45rem;
}
.box.note { background: #EEF4FF; border: 1px solid #BFCFEF; border-left: 3px solid var(--isro-blue); }
.box.note .box-label { color: var(--isro-blue); }
.box.warn { background: var(--highlight); border: 1px solid #E0D090; border-left: 3px solid #AA8800; }
.box.warn .box-label { color: #7A6000; }

/* ─── Tables ────────────────────────────────────────── */
.tbl-wrap { overflow-x: auto; margin: 1.4rem 0; }
table {
  width: 100%; border-collapse: collapse;
  font-family: var(--f-sans); font-size: 0.85rem;
}
table caption {
  caption-side: bottom; font-style: italic;
  font-size: 0.76rem; color: var(--ink-caption);
  text-align: left; padding-top: 0.5rem; line-height: 1.5;
}
thead th {
  background: var(--isro-blue); color: #fff;
  padding: 9px 14px; text-align: left;
  font-weight: 600; font-size: 0.76rem; letter-spacing: 0.04em;
}
thead th.center { text-align: center; }
tbody td {
  padding: 8px 14px; border-bottom: 1px solid var(--border);
  color: var(--ink-body); vertical-align: top;
}
tbody td.center { text-align: center; }
tbody tr:nth-child(even) td { background: var(--paper-tint); }
tbody tr:last-child td { border-bottom: none; }
.val-hi { color: var(--isro-blue); font-weight: 600; }
.val-best { color: var(--green); font-weight: 700; }
.val-na { color: var(--ink-caption); font-size: 0.78rem; }
.val-ours { color: var(--isro-blue); font-weight: 700; }
.ours-row td { background: rgba(0,48,135,0.05) !important; font-weight: 600; }
.badge-new {
  display: inline-block; background: var(--isro-orange); color: #fff;
  font-size: 0.55rem; font-weight: 700; letter-spacing: 0.06em;
  padding: 1px 5px; border-radius: 2px; vertical-align: middle; margin-left: 4px;
}

/* ─── Diagram containers ────────────────────────────── */
.diagram {
  background: var(--paper-tint); border: 1px solid var(--border);
  border-radius: 3px; padding: 1.4rem 1.4rem 1rem;
  margin: 1.6rem 0; overflow-x: auto;
}
.fig-cap {
  font-family: var(--f-sans); font-size: 0.76rem;
  font-style: italic; color: var(--ink-caption);
  display: block; text-align: center; margin-top: 0.6rem;
  line-height: 1.5;
}

/* ─── Equations ─────────────────────────────────────── */
.eq-block {
  background: var(--code-bg); border: 1px solid var(--border);
  border-radius: 2px; padding: 1rem 1.6rem;
  margin: 1.3rem 0; overflow-x: auto;
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem;
}
.eq-block .eq-num {
  font-family: var(--f-mono); font-size: 0.72rem;
  color: var(--ink-muted); white-space: nowrap; flex-shrink: 0;
}
.eq-label {
  font-family: var(--f-sans); font-size: 0.76rem;
  color: var(--ink-muted); font-style: italic;
  text-align: center; display: block; margin-top: 0.4rem;
}

/* ─── Contributions list ────────────────────────────── */
ol.contribs { list-style: none; counter-reset: contrib; padding-left: 0; }
ol.contribs li {
  position: relative;
  padding-left: 2.6rem;
  margin-bottom: 0.75rem;
  font-size: 0.97rem; line-height: 1.75; color: var(--ink-body);
}
ol.contribs li::before {
  content: 'C' counter(contrib) '.';
  counter-increment: contrib;
  position: absolute; left: 0; top: 0.06rem;
  font-family: var(--f-mono); font-size: 0.78rem;
  color: var(--isro-blue); font-weight: 600;
}

/* ─── Problem stats ─────────────────────────────────── */
.stat-row {
  display: grid; grid-template-columns: repeat(3,1fr);
  gap: 1rem; margin: 1.4rem 0;
}
.stat-cell {
  background: var(--paper-tint); border: 1px solid var(--border);
  padding: 1.1rem; text-align: center; border-radius: 2px;
}
.stat-big {
  font-family: var(--f-mono); font-size: 2rem; font-weight: 600;
  color: var(--isro-orange); line-height: 1; display: block;
}
.stat-desc {
  font-family: var(--f-sans); font-size: 0.7rem;
  color: var(--ink-muted); margin-top: 0.35rem; display: block; line-height: 1.45;
}

/* ─── Metric counters ───────────────────────────────── */
.metrics-row {
  display: grid; grid-template-columns: repeat(4,1fr);
  gap: 1rem; margin: 1.6rem 0;
}
.metric {
  border: 1px solid var(--border);
  border-top: 2.5px solid var(--isro-blue);
  padding: 1.2rem 1rem; text-align: center; background: var(--paper);
}
.metric.green { border-top-color: var(--green); }
.metric.orange { border-top-color: var(--isro-orange); }
.m-label {
  font-family: var(--f-sans); font-size: 0.62rem; font-weight: 700;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--ink-muted); margin-bottom: 0.35rem;
}
.m-val {
  font-family: var(--f-mono); font-size: 2rem; font-weight: 600;
  color: var(--isro-blue); line-height: 1; display: block;
}
.metric.green .m-val { color: var(--green); }
.metric.orange .m-val { color: var(--isro-orange); }
.m-ctx {
  font-family: var(--f-sans); font-size: 0.65rem;
  color: var(--ink-caption); margin-top: 0.3rem; line-height: 1.4;
}

/* ─── Bar chart ─────────────────────────────────────── */
.chart-wrap {
  background: var(--paper-tint); border: 1px solid var(--border);
  padding: 1.6rem; margin: 1.6rem 0; border-radius: 2px;
}
.chart-title {
  font-family: var(--f-sans); font-size: 0.8rem; font-weight: 600;
  color: var(--ink); margin-bottom: 0.6rem;
}
.chart-sub {
  font-family: var(--f-sans); font-size: 0.68rem;
  color: var(--ink-muted); margin-bottom: 1.4rem;
}
.legend { display: flex; gap: 1.4rem; font-family: var(--f-sans); font-size: 0.68rem; color: var(--ink-muted); margin-bottom: 1.2rem; }
.leg-dot { display: inline-block; width: 10px; height: 10px; border-radius: 2px; margin-right: 5px; vertical-align: middle; }

.bar-row { display: flex; align-items: center; gap: 1rem; margin-bottom: 0.65rem; }
.bar-name { font-family: var(--f-sans); font-size: 0.76rem; color: var(--ink-body); min-width: 130px; text-align: right; }
.bar-track { flex: 1; background: #E8E4DC; border-radius: 2px; height: 18px; overflow: hidden; }
.bar-fill {
  height: 100%; border-radius: 2px; width: 0%;
  background: var(--isro-blue);
  display: flex; align-items: center; justify-content: flex-end;
  padding-right: 7px;
  transition: width 1.1s cubic-bezier(.4,0,.2,1);
}
.bar-fill.ours { background: linear-gradient(90deg, var(--isro-blue2), var(--isro-orange)); }
.bar-v { font-family: var(--f-mono); font-size: 0.67rem; color: #fff; font-weight: 600; }

/* ─── Image sliders ─────────────────────────────────── */
.sliders-grid {
  display: grid; grid-template-columns: repeat(3,1fr);
  gap: 1.2rem; margin: 1.6rem 0;
}
.slider-card { border: 1px solid var(--border); border-radius: 2px; overflow: hidden; }
.ic {
  position: relative; width: 100%;
  aspect-ratio: 4/3; overflow: hidden; cursor: col-resize;
  user-select: none;
}
/* Placeholder panels — neutral academic grey */
.ic-left, .ic-right {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  flex-direction: column; gap: 0.5rem;
}
.ic-left { background: #C8CDD4; }
.ic-right {
  background: #D6DFD4;
  clip-path: inset(0 50% 0 0);
}
.ic-placeholder-label {
  font-family: var(--f-sans); font-size: 0.65rem;
  font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase;
  color: rgba(0,0,0,0.45); text-align: center; padding: 0 1rem;
  pointer-events: none;
}
.ic-icon {
  font-size: 1.6rem; opacity: 0.35; pointer-events: none;
}
.ic-line {
  position: absolute; top: 0; width: 2px; height: 100%;
  background: #fff; z-index: 5; pointer-events: none;
  left: 50%; transform: translateX(-50%);
}
.ic-handle {
  position: absolute; top: 50%; z-index: 6;
  width: 32px; height: 32px; border-radius: 50%;
  background: #fff; box-shadow: 0 1px 6px rgba(0,0,0,0.25);
  display: flex; align-items: center; justify-content: center;
  pointer-events: none; left: 50%;
  transform: translate(-50%, -50%);
  font-size: 0.6rem; color: #555; font-weight: 700; letter-spacing: -1px;
}
.slider-foot {
  display: flex; justify-content: space-between;
  padding: 5px 10px;
  background: var(--paper-tint); border-top: 1px solid var(--border);
  font-family: var(--f-sans); font-size: 0.66rem; color: var(--ink-muted);
}
.pending-label {
  display: block; text-align: center; margin-top: 0.6rem;
  font-family: var(--f-sans); font-size: 0.73rem;
  font-style: italic; color: var(--ink-muted);
}

/* ─── Team ──────────────────────────────────────────── */
.team-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 1rem; margin-top: 1.4rem; }
.member {
  border: 1px solid var(--border); padding: 1.3rem 1rem;
  text-align: center; background: var(--paper);
  transition: box-shadow 0.2s;
}
.member:hover { box-shadow: 0 3px 12px rgba(0,0,0,0.08); }
.avatar {
  width: 54px; height: 54px; border-radius: 50%;
  background: var(--isro-blue);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--f-sans); font-size: 0.95rem; font-weight: 700;
  color: #fff; margin: 0 auto 0.9rem;
}
.m-name { font-family: var(--f-sans); font-size: 0.88rem; font-weight: 600; color: var(--ink); margin-bottom: 0.2rem; }
.m-role { font-family: var(--f-sans); font-size: 0.65rem; color: var(--isro-orange); font-weight: 700; letter-spacing: 0.07em; text-transform: uppercase; margin-bottom: 0.5rem; }
.m-contrib { font-size: 0.82rem; color: var(--ink-muted); line-height: 1.55; }

/* ─── References ────────────────────────────────────── */
.refs { list-style: none; counter-reset: rc; }
.refs li {
  counter-increment: rc;
  display: flex; gap: 0.8rem;
  margin-bottom: 0.7rem; font-size: 0.85rem; line-height: 1.6; color: var(--ink-body);
}
.refs li::before {
  content: '[' counter(rc) ']';
  font-family: var(--f-mono); font-size: 0.78rem;
  color: var(--isro-blue); font-weight: 600;
  min-width: 28px; flex-shrink: 0; margin-top: 0.05rem;
}
.refs em { color: var(--ink-muted); }

/* ─── Footer ────────────────────────────────────────── */
footer {
  background: var(--isro-blue); color: rgba(255,255,255,0.8);
  text-align: center; padding: 1.8rem 2rem;
  border-top: 3px solid var(--isro-orange);
  font-family: var(--f-sans); font-size: 0.75rem;
}
footer strong { color: #fff; }

/* ─── Scroll reveal ─────────────────────────────────── */
.rv { opacity: 0; transform: translateY(16px); transition: opacity 0.55s ease, transform 0.55s ease; }
.rv.in { opacity: 1; transform: none; }

/* ─── Cite inline ───────────────────────────────────── */
.c { color: var(--isro-blue); font-family: var(--f-sans); font-size: 0.82rem; font-weight: 600; }
.c:hover { text-decoration: underline; }

/* ─── Responsive ────────────────────────────────────── */
@media (max-width: 860px) {
  .nav-text { display: none; }
  nav ul { gap: 1rem; }
  .stat-row { grid-template-columns: 1fr 1fr; }
  .metrics-row { grid-template-columns: 1fr 1fr; gap: 0.8rem; }
  .sliders-grid { grid-template-columns: 1fr 1fr; gap: 0.8rem; }
  .team-grid { grid-template-columns: 1fr 1fr; gap: 0.8rem; }
  .bar-name { min-width: 90px; font-size: 0.7rem; }
}

@media (max-width: 600px) {
  nav {
    height: auto;
    padding: 8px 1rem;
    flex-wrap: wrap;
  }
  .nav-left {
    width: auto;
  }
  .nav-pdf {
    order: 2;
  }
  nav ul {
    order: 3;
    width: 100%;
    justify-content: space-between;
    margin-top: 6px;
    border-top: 1px solid var(--border);
    padding-top: 6px;
    gap: 0.6rem;
    overflow-x: auto;
    white-space: nowrap;
    -webkit-overflow-scrolling: touch;
  }
  nav ul::-webkit-scrollbar { display: none; }
  
  .sec-wrap {
    padding: 32px 1rem;
  }
  .stat-row { grid-template-columns: 1fr; gap: 0.8rem; }
  .sliders-grid { grid-template-columns: 1fr; gap: 1rem; }
  .team-grid { grid-template-columns: 1fr; gap: 0.8rem; }
  .metrics-row { grid-template-columns: 1fr 1fr; gap: 0.6rem; }
  .bar-row { gap: 0.5rem; }
  .bar-name { min-width: 80px; font-size: 0.65rem; }
  .chart-wrap { padding: 1rem; }
}
@media print {
  nav, #progress { display: none; }
  .rv { opacity: 1; transform: none; }
  body { font-size: 12pt; }
  h1.title { font-size: 18pt; }
}