/* ---- Inter (variable, latin + latin-ext) ---- */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
  src: url('assets/fonts/Inter-latin.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
  src: url('assets/fonts/Inter-latin-ext.woff2') format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}

/* ---- Bitkit palette ---- */
:root {
  --brand:       #FF4400;
  --bitcoin:     #F7931A;
  --yellow:      #FFD200;
  --blue:        #0085FF;
  --green:       #75BF72;
  --red:         #E95164;
  --purple:      #B95CE8;

  --bg:          #FFFFFF;
  --surface:     #F7F7F7;
  --surface-2:   #EFEFEF;
  --border:      #E5E5E5;

  --text:        #101010;   /* Bitkit Gray7 */
  --text-muted:  #636366;   /* Bitkit Gray2 */
  --text-soft:   #8E8E8E;   /* Bitkit Gray1 */

  --brand-08:    rgba(255, 68, 0, 0.08);
  --brand-16:    rgba(255, 68, 0, 0.16);

  --font-sans:   'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;

  --slide-pad-x: 6vw;
  --slide-pad-y: 8vh;
}

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
body {
  font-family: var(--font-sans);
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow: hidden;
  font-feature-settings: 'ss01', 'cv11';
}
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---- Progress bar ---- */
.progress {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  width: 0%;
  background: var(--brand);
  z-index: 999;
  transition: width 240ms cubic-bezier(.2,.7,.2,1);
}

/* ---- Slide counter (subtle) ---- */
.counter {
  position: fixed;
  bottom: 14px;
  right: 18px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--text-soft);
  z-index: 998;
  user-select: none;
  font-variant-numeric: tabular-nums;
}
.counter span { color: var(--brand); }

/* ---- Deck & slides ---- */
.deck { position: relative; width: 100vw; height: 100vh; }
.slide {
  position: absolute;
  inset: 0;
  padding: var(--slide-pad-y) var(--slide-pad-x);
  display: none;
  flex-direction: column;
  justify-content: center;
  opacity: 0;
  transition: opacity 200ms ease-out;
}
.slide.active {
  display: flex;
  opacity: 1;
}

/* ---- Typography scale (clamp scales w/ viewport) ---- */
h1.display {
  font-size: clamp(48px, 7.2vw, 108px);
  font-weight: 900;
  line-height: 0.98;
  letter-spacing: -0.025em;
  margin-bottom: 0.4em;
}
h1.title {
  font-size: clamp(40px, 5.4vw, 80px);
  font-weight: 800;
  line-height: 1.02;
  letter-spacing: -0.02em;
  margin-bottom: 0.6em;
}
h2.section-tag {
  font-size: clamp(14px, 1.2vw, 18px);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--brand);
  margin-bottom: 1.2em;
}
h3.h3 {
  font-size: clamp(28px, 3.4vw, 48px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.01em;
  margin-bottom: 0.6em;
}
p.lead {
  font-size: clamp(20px, 2.2vw, 32px);
  line-height: 1.4;
  color: var(--text-muted);
  max-width: 28ch;
}
p.body {
  font-size: clamp(18px, 1.7vw, 24px);
  line-height: 1.5;
  color: var(--text);
}
.muted { color: var(--text-muted); }
.soft { color: var(--text-soft); }
.brand { color: var(--brand); }
.bitcoin { color: var(--bitcoin); }
.green { color: var(--green); }
.red { color: var(--red); }
.blue { color: var(--blue); }
.mono { font-family: ui-monospace, 'SF Mono', Menlo, Consolas, monospace; }
.tight { letter-spacing: -0.02em; }

/* ---- Lists ---- */
ul.bullets {
  list-style: none;
  display: grid;
  gap: 0.8em;
}
ul.bullets li {
  font-size: clamp(18px, 2vw, 28px);
  line-height: 1.45;
  padding-left: 1.8em;
  position: relative;
}
ul.bullets li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 0.8em;
  height: 0.18em;
  background: var(--brand);
  border-radius: 2px;
}
ul.bullets li strong { font-weight: 700; }

/* ---- Layout helpers ---- */
.two-cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(24px, 4vw, 64px);
  align-items: center;
}
.two-cols.with-aside {
  grid-template-columns: 1.4fr 1fr;
}
.center { text-align: center; align-items: center; }
.row { display: flex; align-items: center; gap: 24px; }
.stack { display: flex; flex-direction: column; gap: 16px; }

/* ---- Cards ---- */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: clamp(20px, 2.4vw, 40px);
}
.card.brand {
  background: var(--brand-08);
  border-color: var(--brand-16);
}
.card .label {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--brand);
  margin-bottom: 10px;
}

/* ---- Cover slide ---- */
.cover {
  background: var(--bg);
  align-items: flex-start;
  justify-content: center;
}
.cover .eyebrow {
  font-size: clamp(14px, 1.2vw, 18px);
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--brand);
  margin-bottom: 24px;
}
.cover h1 {
  font-size: clamp(56px, 9vw, 160px);
  font-weight: 900;
  line-height: 0.92;
  letter-spacing: -0.035em;
  margin: 0 0 24px;
}
.cover .subtitle {
  font-size: clamp(22px, 2.6vw, 40px);
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 56px;
  max-width: 22ch;
}
.cover .meta {
  display: flex;
  gap: 28px;
  align-items: center;
  color: var(--text-soft);
  font-size: clamp(14px, 1.2vw, 18px);
  font-weight: 600;
  letter-spacing: 0.04em;
}
.cover .meta .dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--brand);
}
.cover-logo {
  position: absolute;
  top: var(--slide-pad-y);
  right: var(--slide-pad-x);
  height: 36px;
  opacity: 0.85;
}

/* ---- About me slide ---- */
.about-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: clamp(40px, 6vw, 96px);
  align-items: center;
}
.about-grid .qr-block {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}
.about-grid .qr-block img {
  width: clamp(160px, 22vw, 280px);
  height: auto;
}
.about-grid .qr-block .qr-label {
  font-size: 14px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: 0.02em;
}
.about-grid .qr-block .qr-url {
  font-size: 13px;
  color: var(--text-muted);
  font-family: ui-monospace, monospace;
}

/* ---- QR shared ---- */
.qr {
  background: #FFF;
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 12px;
}
.qr-row {
  display: flex;
  gap: clamp(40px, 6vw, 96px);
  justify-content: center;
  align-items: flex-start;
}
.qr-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  max-width: 320px;
}
.qr-card img {
  width: clamp(200px, 24vw, 320px);
  height: auto;
}
.qr-card .qr-title {
  font-size: clamp(18px, 1.6vw, 24px);
  font-weight: 800;
  color: var(--text);
}
.qr-card .qr-sub {
  font-size: clamp(13px, 1.1vw, 16px);
  color: var(--text-muted);
  font-family: ui-monospace, monospace;
  text-align: center;
  word-break: break-all;
}

/* ---- Stat / big number ---- */
.big-number {
  font-size: clamp(72px, 12vw, 200px);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 0.9;
  color: var(--brand);
}
.big-label {
  font-size: clamp(18px, 2vw, 28px);
  color: var(--text-muted);
  font-weight: 500;
  margin-top: 12px;
}

/* ---- Compare table (onchain vs lightning) ---- */
.compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 24px;
}
.compare .col {
  border-radius: 18px;
  padding: clamp(20px, 2.4vw, 36px);
  border: 1px solid var(--border);
  background: var(--surface);
}
.compare .col.lightning {
  background: var(--brand-08);
  border-color: var(--brand-16);
}
.compare .col h4 {
  font-size: 14px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  margin-bottom: 16px;
  color: var(--text-muted);
}
.compare .col.lightning h4 { color: var(--brand); }
.compare .col .val {
  font-size: clamp(28px, 4vw, 56px);
  font-weight: 800;
  letter-spacing: -0.015em;
  line-height: 1.05;
  margin-bottom: 8px;
}
.compare .col .desc {
  font-size: clamp(15px, 1.4vw, 19px);
  color: var(--text-muted);
  line-height: 1.4;
}

/* ---- Quote / callout ---- */
.callout {
  border-left: 6px solid var(--brand);
  padding: 18px 24px;
  background: var(--brand-08);
  border-radius: 0 12px 12px 0;
  font-size: clamp(18px, 1.8vw, 26px);
  font-weight: 500;
  color: var(--text);
}

/* ---- Pills / chips ---- */
.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.pill.brand    { background: var(--brand-08); color: var(--brand); }
.pill.green    { background: rgba(117,191,114,0.14); color: #3d8a3a; }
.pill.red      { background: rgba(233,81,100,0.14); color: #b9344a; }
.pill.bitcoin  { background: rgba(247,147,26,0.14); color: #a35c00; }
.pill.blue     { background: rgba(0,133,255,0.10); color: #0064c2; }

/* ---- Diagram common ---- */
.diagram {
  width: 100%;
  max-width: 1100px;
  height: auto;
  margin: 0 auto;
  display: block;
}

/* ---- HTLC / channel bar ---- */
.channel-bar {
  width: 100%;
  height: clamp(50px, 6vw, 90px);
  background: var(--surface-2);
  border-radius: 12px;
  border: 1px solid var(--border);
  display: flex;
  overflow: hidden;
  position: relative;
}
.channel-bar .local {
  background: var(--brand);
  display: flex;
  align-items: center;
  justify-content: flex-start;
  padding-left: 18px;
  color: #fff;
  font-weight: 800;
  font-size: clamp(16px, 1.6vw, 22px);
  transition: width 600ms cubic-bezier(.2,.7,.2,1);
}
.channel-bar .remote {
  background: var(--blue);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-right: 18px;
  color: #fff;
  font-weight: 800;
  font-size: clamp(16px, 1.6vw, 22px);
  transition: width 600ms cubic-bezier(.2,.7,.2,1);
}

/* ---- Recap / objective list ---- */
.objectives {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-top: 32px;
}
.objectives .obj {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: clamp(24px, 2.6vw, 40px);
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.objectives .obj .num {
  font-size: clamp(28px, 3vw, 44px);
  font-weight: 900;
  color: var(--brand);
  line-height: 1;
}
.objectives .obj .obj-title {
  font-size: clamp(17px, 1.6vw, 22px);
  font-weight: 700;
  line-height: 1.25;
}
.objectives .obj .obj-desc {
  font-size: clamp(14px, 1.2vw, 17px);
  color: var(--text-muted);
  line-height: 1.4;
}

/* ---- Logo strip (footer) ---- */
.footer-strip {
  position: absolute;
  bottom: var(--slide-pad-y);
  left: var(--slide-pad-x);
  right: var(--slide-pad-x);
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--text-soft);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  pointer-events: none;
}

/* ---- Mobile/timeline ---- */
.timeline {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
  margin-top: 24px;
}
.timeline .step {
  background: var(--surface);
  border-radius: 14px;
  padding: 18px;
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 10px;
  text-align: center;
}
.timeline .step .step-num {
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--brand);
}
.timeline .step .step-text {
  font-size: clamp(13px, 1.1vw, 16px);
  font-weight: 600;
  line-height: 1.3;
  color: var(--text);
}
.timeline .step.dim { opacity: 0.6; }
.timeline .step.active {
  background: var(--brand-08);
  border-color: var(--brand-16);
}

/* ---- Helper visibility for print/PDF ---- */
@media print {
  .progress, .counter { display: none; }
  .slide { display: flex !important; opacity: 1 !important; position: relative !important; page-break-after: always; height: 100vh; }
}

/* ---- Reduced motion ---- */
@media (prefers-reduced-motion: reduce) {
  .slide, .progress, .channel-bar .local, .channel-bar .remote {
    transition: none !important;
  }
  * { animation: none !important; }
}