/*
Theme Name: Lumina AI
Theme URI: https://lumina247.com
Author: Lumina AI
Author URI: https://lumina247.com
Description: Official Lumina AI website theme. Clean, editorial design with serif typography.
Version: 1.0.0
Requires at least: 6.0
Tested up to: 6.7
Requires PHP: 8.0
License: Proprietary
Text Domain: lumina-ai
*/

/* ─── Google Fonts ─────────────────────────────────────────── */
@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,300;9..144,400;9..144,500&family=Spline+Sans:wght@300;400;500&display=swap');

/* ─── Custom Properties ────────────────────────────────────── */
:root {
  --ink-color:   #1f2724;
  --soft-color:  #5c655f;
  --faint-color: #8a918b;
  --line-color:  #e4e3dc;
  --paper-color: #faf9f5;

  --font-sans:  'Spline Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-serif: 'Fraunces', Georgia, serif;
  --font-mono:  Menlo, monospace;
}

/* ─── Reset & Base ─────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background-color: var(--paper-color);
  color: var(--ink-color);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul {
  list-style: none;
}

/* ─── Fade-in Animation ────────────────────────────────────── */
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-up {
  animation: fadeUp 0.9s cubic-bezier(0.2, 0.7, 0.2, 1) both;
}

.fade-up-1 { animation-delay: 0s;     }
.fade-up-2 { animation-delay: 0.10s;  }
.fade-up-3 { animation-delay: 0.25s;  }
.fade-up-4 { animation-delay: 0.40s;  }
.fade-up-5 { animation-delay: 0.50s;  }
.fade-up-6 { animation-delay: 0.65s;  }

@media (prefers-reduced-motion: reduce) {
  .fade-up { animation: none; }
}

/* ─── Layout ───────────────────────────────────────────────── */
.site {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.site-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 5rem 1.75rem;
}

.site-inner {
  width: 100%;
  max-width: 30rem;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* ─── Logo ─────────────────────────────────────────────────── */
.site-logo {
  margin-bottom: 2.5rem;
  height: 3.5rem;
  width: auto;
}

/* ─── Homepage Hero ────────────────────────────────────────── */
.hero-title {
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: 2.1rem;
  letter-spacing: 0.01em;
  color: var(--ink-color);
}

.hero-description {
  margin-top: 1rem;
  max-width: 30rem;
  color: var(--soft-color);
  font-size: 1.02rem;
}

/* ─── Divider ──────────────────────────────────────────────── */
.divider {
  width: 34px;
  height: 1px;
  background-color: var(--line-color);
  margin: 2.125rem auto;
  border: none;
}

/* ─── Contact Info ─────────────────────────────────────────── */
.contact-info {
  display: flex;
  flex-direction: column;
  gap: 0.4375rem;
  font-size: 0.92rem;
  color: var(--faint-color);
}

.contact-info a {
  color: var(--soft-color);
  border-bottom: 1px solid var(--line-color);
  transition: color 0.25s ease, border-color 0.25s ease;
}

.contact-info a:hover {
  color: var(--ink-color);
  border-color: var(--faint-color);
}

/* ─── Research Section ─────────────────────────────────────── */
.research-section {
  margin-top: 3.75rem;
  width: 100%;
  max-width: 33rem;
}

.research-section-title {
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--faint-color);
  margin-bottom: 1.375rem;
}

.research-list {
  text-align: left;
  width: 100%;
}

.research-list li {
  border-top: 1px solid var(--line-color);
}

.research-list li:last-child {
  border-bottom: 1px solid var(--line-color);
}

.research-list a {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1.125rem;
  padding: 0.9375rem 0.25rem;
  color: var(--ink-color);
  transition: background-color 0.2s ease, padding-left 0.2s ease;
}

.research-list a:hover {
  background-color: rgba(0, 0, 0, 0.05);
  padding-left: 0.625rem;
}

.research-list .paper-title {
  font-size: 0.94rem;
  line-height: 1.45;
}

.research-list .paper-year {
  font-size: 0.82rem;
  color: var(--faint-color);
  font-variant-numeric: tabular-nums;
  flex-shrink: 0;
}

/* ─── Single Research Post ─────────────────────────────────── */
.research-post {
  max-width: 42rem;
  margin: 0 auto;
  padding: 4rem 1.75rem;
}

.research-post-title {
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: 1.75rem;
  letter-spacing: 0.01em;
  margin-bottom: 0.75rem;
  color: var(--ink-color);
}

.research-post-meta {
  font-size: 0.82rem;
  color: var(--faint-color);
  margin-bottom: 2.5rem;
}

.research-post-content {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--soft-color);
}

.research-post-content p {
  margin-bottom: 1.25rem;
}

.back-link {
  display: inline-block;
  margin-top: 3rem;
  font-size: 0.88rem;
  color: var(--soft-color);
  border-bottom: 1px solid var(--line-color);
  transition: color 0.2s ease, border-color 0.2s ease;
}

.back-link:hover {
  color: var(--ink-color);
  border-color: var(--faint-color);
}

/* ─── Archive Page ─────────────────────────────────────────── */
.archive-header {
  margin-bottom: 2.5rem;
}

.archive-title {
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: 2rem;
  color: var(--ink-color);
}

/* ─── Footer ───────────────────────────────────────────────── */
.site-footer {
  text-align: center;
  padding: 2rem 1.75rem;
  font-size: 0.8rem;
  color: var(--faint-color);
}

/* ─── Selection ────────────────────────────────────────────── */
::selection {
  background-color: var(--line-color);
  color: var(--ink-color);
}