/* Shared Reveal.js styles for slide-reactive decks. */

:root {
  --slide-navy: #15324b;
  --slide-blue: #1769aa;
  --slide-cyan: #e9f5ff;
  --slide-gold: #d48b18;
}

.reveal .slides section > h2 {
  color: var(--slide-navy);
  border-bottom: 4px solid rgba(23, 105, 170, 0.2);
  padding-bottom: 0.16em;
}

.reveal .slides section.center-h > h2 {
  border-bottom: 0;
}

.reveal .center-h {
  text-align: center !important;
}

.reveal .slides section.level1.section-title {
  /* Keep vertical slides overlaid at top:0; relative positioning makes this
     section occupy 900px in the stack and pushes every following slide down. */
  position: absolute;
  isolation: isolate;
  display: flex !important;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  box-sizing: border-box;
  min-height: 100%;
  padding: 7% 9%;
  overflow: hidden;
  text-align: center;
}

.reveal .slides section.level1.section-title > h1 {
  position: relative;
  z-index: 1;
  max-width: 86%;
  margin: 0;
  font-size: 2.1em;
  line-height: 1.18;
  letter-spacing: 0.06em;
}

.reveal .slides section.level1.section-title > h1::after {
  content: "";
  display: block;
  width: 2.4em;
  height: 0.09em;
  margin: 0.42em auto 0;
  border-radius: 999px;
  background: currentColor;
  opacity: 0.72;
}

/* Default: academic gradient with a subtle grid. */
.reveal .slides section.level1.section-title--academic {
  color: #fff;
  background:
    linear-gradient(rgba(255, 255, 255, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.055) 1px, transparent 1px),
    linear-gradient(135deg, #102f4c 0%, #1769aa 58%, #62afd4 100%);
  background-size: 52px 52px, 52px 52px, 100% 100%;
}

.reveal .slides section.level1.section-title--academic > h1 {
  color: #fff;
  text-shadow: 0 4px 20px rgba(5, 27, 48, 0.35);
}

/* Alternative: shared cover image with a dark overlay. */
.reveal .slides section.level1.section-title--image {
  color: #fff;
  background:
    linear-gradient(110deg, rgba(9, 37, 61, 0.9), rgba(23, 105, 170, 0.58)),
    url("../../pic/slide-front-page.jpg") center / cover no-repeat;
}

.reveal .slides section.level1.section-title--image > h1 {
  color: #fff;
  text-shadow: 0 3px 18px rgba(0, 0, 0, 0.55);
}

/* Alternative: restrained light background with a left accent. */
.reveal .slides section.level1.section-title--minimal {
  align-items: flex-start;
  color: var(--slide-navy);
  background: linear-gradient(110deg, #fff 0 68%, var(--slide-cyan) 68% 100%);
  text-align: left;
}

.reveal .slides section.level1.section-title--minimal::before {
  content: "";
  position: absolute;
  inset: 18% auto 18% 6%;
  width: 0.22em;
  border-radius: 999px;
  background: var(--slide-blue);
}

.reveal .slides section.level1.section-title--minimal > h1 {
  color: var(--slide-navy);
}

.reveal .slides section.level1.section-title--minimal > h1::after {
  margin-left: 0;
  background: var(--slide-gold);
}

/* Alternative: dark background with a soft spotlight. */
.reveal .slides section.level1.section-title--spotlight {
  color: #fff;
  background:
    radial-gradient(circle at 50% 42%, rgba(91, 181, 224, 0.38), transparent 34%),
    linear-gradient(145deg, #071c2d, #153c5d 55%, #071c2d);
}

.reveal .slides section.level1.section-title--spotlight > h1 {
  color: #fff;
  text-shadow: 0 0 28px rgba(133, 211, 246, 0.5);
}

.reveal .slide-logo {
  max-height: 2.8rem !important;
  max-width: 360px !important;
  height: auto !important;
  width: auto !important;
  bottom: 10px !important;
  right: 14px !important;
}

.reveal .footer {
  position: fixed;
  left: 16px;
  right: auto;
  bottom: 14px !important;
  font-size: 16px !important;
  color: #4a5568;
  letter-spacing: 0.02em;
  text-shadow: 0 0 8px #fff, 0 0 8px #fff;
}

.reveal .slide-number {
  position: fixed;
  top: 14px;
  right: 18px;
  bottom: auto !important;
  font-size: 18px !important;
  color: #4a5568;
  background: none;
}