/* ==========================================================
   FAKE CURRENCY DETECTION — LIGHT THEME
   Inspired by sarvam.ai
   Author: Raushan Kumar · NIT Nagaland
   Fonts: Instrument Serif (headings) + Plus Jakarta Sans (body)
   Palette: warm cream/peach, black text, no purple
   ========================================================== */

:root {
  --bg: #fefcf9;
  --bg-warm: #fdf6ee;
  --bg-card: #ffffff;
  --border: #e8e2da;
  --border-light: #f0ebe4;
  --text: #1a1a1a;
  --text-2: #555;
  --text-3: #999;
  --accent: #d4a574;
  --accent-dark: #b8875a;
  --black: #1a1a1a;
  --white: #fff;
  --green: #2d8a4e;
  --red: #c53030;
  --amber: #d69e2e;
  --heading: 'Instrument Serif', Georgia, serif;
  --body: 'Plus Jakarta Sans', system-ui, sans-serif;
  --mono: 'JetBrains Mono', monospace;
  --r: 12px;
  --r-lg: 20px;
  --r-pill: 100px;
  --ease: cubic-bezier(.4,0,.2,1);
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
code {
  font-family: var(--mono);
  background: rgba(0,0,0,.05);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: .85em;
}

/* ─── Nav ─── */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  padding: 16px 0;
  transition: background .3s var(--ease), box-shadow .3s var(--ease), padding .3s var(--ease);
}
.nav.scrolled {
  padding: 10px 0;
  background: rgba(254,252,249,.92);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 1px 0 var(--border);
}
.nav-inner {
  max-width: 1120px; margin: 0 auto; padding: 0 24px;
  display: flex; align-items: center; justify-content: space-between;
}
.nav-brand {
  font-family: var(--body); font-weight: 700; font-size: 1.1rem;
  letter-spacing: -.02em; color: var(--text);
}
.nav-links { display: flex; gap: 6px; }
.nav-link {
  padding: 7px 16px; font-size: .88rem; font-weight: 500;
  color: var(--text-2); border-radius: var(--r-pill);
  transition: color .2s, background .2s;
}
.nav-link:hover, .nav-link.active { color: var(--text); background: rgba(0,0,0,.04); }
.nav-right { display: flex; gap: 8px; }
.nav-cta {
  padding: 8px 20px; font-size: .88rem; font-weight: 600;
  border-radius: var(--r-pill); transition: all .25s var(--ease);
  background: var(--black); color: var(--white);
}
.nav-cta:hover { background: #333; transform: translateY(-1px); }
.nav-cta-outline {
  background: var(--white); color: var(--text);
  border: 1px solid var(--border);
}
.nav-cta-outline:hover { background: #f9f6f2; border-color: #ccc; }
.nav-hamburger {
  display: none; flex-direction: column; gap: 5px;
  background: none; border: none; cursor: pointer; padding: 6px;
}
.nav-hamburger span { width: 22px; height: 2px; background: var(--text); border-radius: 2px; transition: .2s; }
.nav-hamburger.open span:nth-child(1) { transform: rotate(45deg) translate(5px,5px); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; }
.nav-hamburger.open span:nth-child(3) { transform: rotate(-45deg) translate(5px,-5px); }

/* ─── Hero ─── */
.hero {
  min-height: 100vh; display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  text-align: center; position: relative; overflow: hidden;
  padding: 140px 24px 60px;
}
.hero-gradient {
  position: absolute; bottom: 0; left: 0; right: 0; height: 55%;
  background: linear-gradient(180deg, transparent 0%, rgba(253,210,170,.18) 40%, rgba(250,190,140,.22) 70%, rgba(253,246,238,1) 100%);
  pointer-events: none;
}
.hero-ornament {
  color: var(--accent); margin-bottom: 32px; position: relative; z-index: 1;
}
.hero-content { position: relative; z-index: 1; }
.hero-chip {
  display: inline-block; padding: 6px 18px;
  border: 1px solid var(--border); border-radius: var(--r-pill);
  font-size: .82rem; font-weight: 500; color: var(--text-2);
  margin-bottom: 28px; background: var(--white);
}
.hero-h1 {
  font-family: var(--heading); font-weight: 400;
  font-size: clamp(2.4rem, 5.5vw, 4.2rem);
  line-height: 1.15; letter-spacing: -.02em;
  margin-bottom: 22px; color: var(--text);
}
.hero-sub {
  font-size: 1.05rem; color: var(--text-2);
  line-height: 1.8; margin-bottom: 36px;
}
.hero-btns { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 28px; font-size: .92rem; font-weight: 600;
  border-radius: var(--r-pill); transition: all .25s var(--ease);
  cursor: pointer; border: none; font-family: var(--body);
}
.btn-dark { background: var(--black); color: var(--white); }
.btn-dark:hover { background: #333; transform: translateY(-2px); box-shadow: 0 4px 16px rgba(0,0,0,.15); }
.btn-outline { background: var(--white); color: var(--text); border: 1px solid var(--border); }
.btn-outline:hover { background: #f9f6f2; border-color: #bbb; transform: translateY(-2px); }
.btn-sm { padding: 9px 20px; font-size: .85rem; }
.hero-tagline {
  position: relative; z-index: 1;
  margin-top: auto; padding-top: 60px;
  font-size: .72rem; letter-spacing: .15em;
  font-weight: 600; color: var(--text-3); text-transform: uppercase;
}

/* ─── Sections ─── */
.section { padding: 100px 0; }
.section-warm { background: var(--bg-warm); }
.container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }
.sec-head { text-align: center; margin-bottom: 56px; }
.sec-chip {
  display: inline-block; padding: 5px 16px;
  border: 1px solid var(--border); border-radius: var(--r-pill);
  font-size: .76rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: .1em; color: var(--text-2); background: var(--white);
  margin-bottom: 20px;
}
.sec-title {
  font-family: var(--heading); font-weight: 400;
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  line-height: 1.2; letter-spacing: -.01em; margin-bottom: 14px;
}
.sec-sub { font-size: 1rem; color: var(--text-2); max-width: 560px; margin: 0 auto; line-height: 1.8; }

/* ─── Info Cards (About) ─── */
.card-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.info-card {
  padding: 30px 24px; border: 1px solid var(--border-light);
  border-radius: var(--r-lg); background: var(--bg-card);
  transition: all .3s var(--ease);
}
.info-card:hover { border-color: var(--border); box-shadow: 0 8px 30px rgba(0,0,0,.04); transform: translateY(-4px); }
.ic-icon {
  width: 44px; height: 44px; border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  background: rgba(212,165,116,.1); color: var(--accent-dark);
  margin-bottom: 16px; transition: transform .3s var(--ease);
}
.info-card:hover .ic-icon { transform: scale(1.08); }
.info-card h3 { font-family: var(--body); font-size: .98rem; font-weight: 600; margin-bottom: 8px; }
.info-card p { font-size: .88rem; color: var(--text-2); line-height: 1.6; }

/* ─── Feature Cards ─── */
.feat-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.feat-card {
  padding: 30px 24px; border: 1px solid var(--border-light);
  border-radius: var(--r-lg); background: var(--bg-card);
  transition: all .3s var(--ease); position: relative; overflow: hidden;
}
.feat-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-dark));
  transform: scaleX(0); transform-origin: left; transition: transform .4s var(--ease);
}
.feat-card:hover { border-color: var(--border); box-shadow: 0 8px 30px rgba(0,0,0,.04); transform: translateY(-4px); }
.feat-card:hover::before { transform: scaleX(1); }
.feat-num {
  font-family: var(--mono); font-size: 1.6rem; font-weight: 500;
  color: var(--accent); opacity: .4; margin-bottom: 12px; display: block;
}
.feat-card h3 { font-size: .98rem; font-weight: 600; margin-bottom: 8px; }
.feat-card p { font-size: .88rem; color: var(--text-2); line-height: 1.6; }

/* ─── Tech Grid ─── */
.tech-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: 16px; }
.tech-item {
  text-align: center; padding: 28px 12px;
  border: 1px solid var(--border-light); border-radius: var(--r-lg);
  background: var(--bg-card); transition: all .3s var(--ease);
}
.tech-item:hover { border-color: var(--border); transform: translateY(-3px); box-shadow: 0 6px 20px rgba(0,0,0,.04); }
.tech-dot { width: 10px; height: 10px; border-radius: 50%; margin: 0 auto 12px; }
.tech-name { display: block; font-weight: 600; font-size: .92rem; margin-bottom: 2px; }
.tech-desc { display: block; font-size: .76rem; color: var(--text-3); }

/* ─── Steps / Timeline ─── */
.steps { max-width: 620px; margin: 0 auto; }
.step {
  display: flex; gap: 20px; margin-bottom: 24px; align-items: flex-start;
}
.step-num {
  flex-shrink: 0; width: 40px; height: 40px;
  border: 1.5px solid var(--border); border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--mono); font-size: .9rem; font-weight: 500;
  color: var(--text-2); background: var(--white);
}
.step-body {
  flex: 1; padding: 20px 24px;
  border: 1px solid var(--border-light); border-radius: var(--r);
  background: var(--bg-card); transition: .3s var(--ease);
}
.step-body:hover { border-color: var(--border); box-shadow: 0 4px 16px rgba(0,0,0,.03); }
.step-body h3 { font-size: .95rem; font-weight: 600; margin-bottom: 6px; }
.step-body p { font-size: .88rem; color: var(--text-2); line-height: 1.6; }

/* ─── Author ─── */
.author-card {
  display: flex; align-items: center; gap: 36px;
  padding: 40px 48px; border: 1px solid var(--border-light);
  border-radius: var(--r-lg); background: var(--bg-card);
  max-width: 640px; margin: 0 auto;
  transition: .3s var(--ease);
}
.author-card:hover { box-shadow: 0 8px 30px rgba(0,0,0,.05); }
.author-photo {
  width: 100px; height: 100px; border-radius: 50%;
  object-fit: cover; object-position: center top;
  border: 3px solid var(--border-light); flex-shrink: 0;
}
.author-info h3 { font-family: var(--heading); font-size: 1.5rem; font-weight: 400; margin-bottom: 12px; }
.author-details { list-style: none; display: flex; flex-direction: column; gap: 8px; }
.author-details li {
  display: flex; align-items: center; gap: 10px;
  font-size: .88rem; color: var(--text-2);
}
.author-details svg { flex-shrink: 0; color: var(--text-3); }

/* ══════════════════════════
   LIVE DEMO
   ══════════════════════════ */
.demo-wrap {
  max-width: 920px; margin: 0 auto;
  border: 1px solid var(--border-light);
  border-radius: var(--r-lg); background: var(--bg-card);
  overflow: hidden;
}
.demo-tabs {
  display: flex; border-bottom: 1px solid var(--border-light);
}
.demo-tab {
  flex: 1; display: flex; align-items: center; justify-content: center; gap: 8px;
  padding: 14px; font-size: .88rem; font-weight: 600; color: var(--text-2);
  background: none; border: none; cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: all .2s;
}
.demo-tab:hover { color: var(--text); background: rgba(0,0,0,.02); }
.demo-tab.active { color: var(--text); border-bottom-color: var(--black); }
.demo-tab svg { opacity: .6; }
.demo-tab.active svg { opacity: 1; }

.demo-body { display: grid; grid-template-columns: 1fr 1fr; min-height: 400px; }
.demo-input { padding: 28px; border-right: 1px solid var(--border-light); }
.demo-output { padding: 28px; }

/* Upload zone */
.upload-zone {
  border: 1.5px dashed var(--border);
  border-radius: var(--r); padding: 48px 24px;
  text-align: center; cursor: pointer;
  transition: .25s var(--ease); background: rgba(0,0,0,.01);
}
.upload-zone:hover, .upload-zone.drag-over { border-color: var(--accent); background: rgba(212,165,116,.04); }
.upload-zone svg { color: var(--text-3); margin: 0 auto 14px; display: block; }
.upload-main { font-size: .92rem; color: var(--text-2); margin-bottom: 4px; }
.upload-browse { color: var(--accent-dark); font-weight: 600; cursor: pointer; }
.upload-hint { font-size: .78rem; color: var(--text-3); }

/* Camera zone */
.camera-zone { position: relative; border-radius: var(--r); overflow: hidden; background: #000; }
.camera-zone video { width: 100%; display: block; min-height: 260px; object-fit: cover; }
.camera-overlay {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  pointer-events: none;
}
.camera-frame {
  width: 75%; height: 55%; border: 2px solid rgba(255,255,255,.5);
  border-radius: 8px; position: relative;
}
.camera-frame::before, .camera-frame::after {
  content: ''; position: absolute; width: 20px; height: 20px;
  border-color: #fff; border-style: solid;
}
.camera-frame::before { top: -2px; left: -2px; border-width: 3px 0 0 3px; border-radius: 4px 0 0 0; }
.camera-frame::after { bottom: -2px; right: -2px; border-width: 0 3px 3px 0; border-radius: 0 0 4px 0; }
.camera-controls { padding: 12px; text-align: center; background: rgba(0,0,0,.6); position: relative; z-index: 10; }

/* Preview zone */
.preview-zone {
  position: relative; border-radius: var(--r); overflow: hidden;
  border: 1px solid var(--border-light); background: #fafaf8;
}
.preview-zone img { width: 100%; max-height: 280px; object-fit: contain; display: block; }
.preview-scanline {
  position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), var(--accent-dark), transparent);
  box-shadow: 0 0 12px rgba(212,165,116,.5);
  display: none;
}
.preview-scanline.active { display: block; animation: scanD 2s ease-in-out infinite; }
@keyframes scanD { 0%,100%{top:0} 50%{top:calc(100% - 2px)} }

/* Controls */
.input-controls { margin-top: 18px; }
.denom-row { display: flex; align-items: center; justify-content: space-between; margin-bottom: 14px; }
.denom-label { font-size: .85rem; font-weight: 500; color: var(--text-2); }
.denom-btns { display: flex; gap: 8px; }
.denom-btn {
  padding: 7px 22px; border-radius: var(--r-pill);
  font-family: var(--mono); font-size: .88rem; font-weight: 500;
  border: 1px solid var(--border); background: var(--white); color: var(--text-2);
  cursor: pointer; transition: .2s;
}
.denom-btn.active, .denom-btn:hover { background: var(--black); color: var(--white); border-color: var(--black); }
.action-row { display: flex; gap: 8px; }
.action-row .btn { flex: 1; justify-content: center; }

/* Output */
.output-empty {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  min-height: 300px; color: var(--text-3); text-align: center; gap: 12px;
}
.output-empty svg { opacity: .25; }
.output-empty p { font-size: .9rem; max-width: 200px; }

/* Verdict */
.verdict {
  display: flex; align-items: center; gap: 12px;
  padding: 14px 18px; border-radius: var(--r);
  margin-bottom: 22px; border: 1px solid var(--border-light);
}
.verdict.pass { border-color: rgba(45,138,78,.25); background: rgba(45,138,78,.04); }
.verdict.fail { border-color: rgba(197,48,48,.25); background: rgba(197,48,48,.04); }
.verdict.analyzing { border-color: rgba(212,165,116,.3); background: rgba(212,165,116,.06); }
.verdict-dot {
  width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0;
}
.verdict.pass .verdict-dot { background: var(--green); }
.verdict.fail .verdict-dot { background: var(--red); }
.verdict.analyzing .verdict-dot { background: var(--amber); animation: blink 1s infinite; }
@keyframes blink { 0%,100%{opacity:1}50%{opacity:.3} }
.verdict strong { font-size: .92rem; display: block; }
.verdict span { font-size: .8rem; color: var(--text-2); }

/* Ring */
.ring-wrap { text-align: center; margin-bottom: 20px; position: relative; width: 100px; height: 100px; margin: 0 auto 20px; }
.ring-svg { width: 100%; height: 100%; }
.ring-val {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%,-50%);
  font-family: var(--mono); font-size: 1.2rem; font-weight: 600;
}

/* Result bars */
.result-bars { display: flex; flex-direction: column; gap: 12px; }
.rbar { display: flex; flex-direction: column; gap: 4px; }
.rbar-top { display: flex; justify-content: space-between; }
.rbar-name { font-size: .8rem; color: var(--text-2); }
.rbar-score { font-family: var(--mono); font-size: .8rem; font-weight: 600; }
.rbar-track { height: 5px; background: #eee; border-radius: 3px; overflow: hidden; }
.rbar-fill { height: 100%; border-radius: 3px; width: 0%; transition: width 1s var(--ease); }
.rbar-fill.high { background: var(--green); }
.rbar-fill.mid { background: var(--amber); }
.rbar-fill.low { background: var(--red); }

/* ─── Footer ─── */
.footer { padding: 48px 0 32px; border-top: 1px solid var(--border-light); }
.footer-inner { text-align: center; }
.footer-brand { font-family: var(--body); font-weight: 700; font-size: 1.05rem; display: block; margin-bottom: 8px; }
.footer p { font-size: .88rem; color: var(--text-2); }
.footer-line { width: 40px; height: 1.5px; background: var(--border); margin: 20px auto; }
.footer-copy { font-size: .78rem; color: var(--text-3); }
.footer-copy a { color: var(--accent-dark); }

/* ─── Modal ─── */
.modal {
  position: fixed; inset: 0; background: rgba(0,0,0,.4); backdrop-filter: blur(4px);
  z-index: 1000; display: none; align-items: center; justify-content: center;
  padding: 20px; opacity: 0; transition: opacity .3s var(--ease);
}
.modal.open { display: flex; opacity: 1; }
.modal-box {
  background: var(--bg-card); width: 100%; max-width: 440px;
  border-radius: var(--r-lg); padding: 32px;
  box-shadow: 0 16px 40px rgba(0,0,0,.15);
  transform: translateY(20px) scale(0.95); transition: all .3s var(--ease);
}
.modal.open .modal-box { transform: translateY(0) scale(1); }
.modal-input {
  width: 100%; padding: 12px 16px; border: 1px solid var(--border);
  border-radius: var(--r); font-family: var(--mono); font-size: .9rem;
  background: var(--bg); color: var(--text); outline: none; transition: .2s;
}
.modal-input:focus { border-color: var(--black); box-shadow: 0 0 0 3px rgba(0,0,0,.05); }

/* ─── Reveal ─── */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity .6s ease, transform .6s ease; }
.reveal.vis { opacity: 1; transform: translateY(0); }

/* ─── Responsive ─── */
@media(max-width:1024px) {
  .card-row { grid-template-columns: repeat(2,1fr); }
  .feat-grid { grid-template-columns: repeat(2,1fr); }
  .tech-grid { grid-template-columns: repeat(3,1fr); }
}
@media(max-width:768px) {
  .nav-links, .nav-right { display: none; }
  .nav-links.open { display: flex; position: absolute; top: 100%; left: 0; right: 0; flex-direction: column; background: rgba(254,252,249,.97); backdrop-filter: blur(20px); padding: 12px 24px; border-bottom: 1px solid var(--border); }
  .nav-right.open { display: flex; flex-direction: column; position: absolute; top: 100%; left: 0; right: 0; padding: 0 24px 16px; background: rgba(254,252,249,.97); }
  .nav-hamburger { display: flex; }
  .card-row, .feat-grid { grid-template-columns: 1fr; }
  .tech-grid { grid-template-columns: repeat(2,1fr); }
  .demo-body { grid-template-columns: 1fr; }
  .demo-input { border-right: none; border-bottom: 1px solid var(--border-light); }
  .author-card { flex-direction: column; text-align: center; padding: 28px; }
  .author-details { align-items: center; }
  .section { padding: 72px 0; }
  .hero { padding: 120px 20px 40px; }
}
@media(max-width:480px) {
  .hero-h1 { font-size: 2rem; }
  .tech-grid { grid-template-columns: repeat(2,1fr); }
  .upload-zone { padding: 32px 16px; }
}