/* ============================================
   Dynamic Torsion Theory — Shared Styles
   © 2026 AkMCC. All Rights Reserved.
   ============================================ */

:root {
  --orange: #ff6b35;
  --cyan: #00ccff;
  --blue: #5af;
  --green: #44ff44;
  --bg: #0a0a14;
  --bg2: #111;
  --border: #1a1a1a;
  --text: #e0e0e0;
  --muted: #888;
  --dim: #555;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--orange); text-decoration: none; transition: opacity .2s; }
a:hover { opacity: .8; }

/* ---- Nav bar ---- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 24px; height: 52px;
  background: rgba(10,10,20,.92);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(255,107,53,.15);
}
.nav-brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: .95em; letter-spacing: 2px;
  color: var(--orange); text-transform: uppercase;
}
.nav-brand span { color: var(--text); font-weight: 400; letter-spacing: 0; text-transform: none; font-size: .85em; }
.nav-links { display: flex; gap: 8px; align-items: center; }
.nav-links a {
  color: var(--muted); font-size: .78em; font-weight: 500;
  letter-spacing: .3px; transition: all .2s;
  padding: 6px 14px; border-radius: 20px; border: 1px solid transparent;
}
.nav-links a:hover { color: var(--orange); opacity: 1; background: rgba(255,107,53,.08); border-color: rgba(255,107,53,.2); }
.nav-links a.nav-active { color: var(--orange); border-color: rgba(255,107,53,.25); background: rgba(255,107,53,.06); }
.nav-links .nav-cta {
  color: #fff; background: var(--orange); border-color: var(--orange);
  font-weight: 600; padding: 6px 16px;
}
.nav-links .nav-cta:hover { background: #e55a28; opacity: 1; }

/* ---- Hero section ---- */
.hero {
  min-height: 100vh; display: flex; flex-direction: column;
  align-items: center; justify-content: center; text-align: center;
  padding: 80px 24px 60px; position: relative; overflow: hidden;
}
.hero::before {
  content: ''; position: absolute; inset: 0;
  background: url('imageperfil.png') center center / cover no-repeat;
  opacity: .18;
  pointer-events: none;
}
.hero::after {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse at center, rgba(255,107,53,.08) 0%, rgba(10,10,20,.95) 70%);
  pointer-events: none;
}
.hero h1 {
  font-size: clamp(2em, 5vw, 3.5em); font-weight: 200;
  letter-spacing: 6px; text-transform: uppercase; margin-bottom: 8px;
  position: relative; z-index: 1;
}
.hero h1 strong { font-weight: 700; color: var(--orange); }
.hero .subtitle {
  font-size: clamp(.85em, 2vw, 1.1em); color: var(--muted);
  max-width: 600px; line-height: 1.6; margin-bottom: 32px;
  position: relative; z-index: 1;
}
.hero .author {
  font-size: .75em; color: var(--dim); margin-bottom: 40px;
  letter-spacing: 1px; position: relative; z-index: 1;
}

/* ---- Card grid ---- */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px; max-width: 960px; width: 100%; padding: 0 20px;
  position: relative; z-index: 1;
}
.crd {
  background: linear-gradient(135deg, rgba(26,26,62,.6), rgba(17,17,17,.8));
  border: 1px solid var(--border); border-radius: 14px;
  padding: 28px 24px; transition: all .3s; position: relative; overflow: hidden;
}
.crd:hover {
  border-color: var(--orange);
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(255,107,53,.08);
}
.crd .icon { font-size: 2em; margin-bottom: 12px; display: block; }
.crd h3 { font-size: 1.05em; margin-bottom: 6px; color: #fff; }
.crd p { font-size: .85em; color: var(--muted); line-height: 1.5; }
.crd .tag {
  display: inline-block; margin-top: 14px; padding: 4px 12px;
  font-size: .7em; border-radius: 20px; font-weight: 600;
  letter-spacing: .5px;
}
.crd .tag.gpu { background: rgba(255,107,53,.12); color: var(--orange); border: 1px solid rgba(255,107,53,.3); }
.crd .tag.cpu { background: rgba(0,204,255,.1); color: var(--cyan); border: 1px solid rgba(0,204,255,.3); }
.crd .tag.pdf-tag { background: rgba(90,170,255,.1); color: var(--blue); border: 1px solid rgba(90,170,255,.3); }

/* ---- Papers section ---- */
.papers {
  padding: 80px 24px; text-align: center;
}
.papers h2 {
  font-size: 1.4em; font-weight: 300; letter-spacing: 3px;
  text-transform: uppercase; margin-bottom: 8px;
}
.papers .sub { color: var(--muted); font-size: .9em; margin-bottom: 30px; }
.pdf-links { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.pdf-btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 24px; border-radius: 10px; font-size: .88em;
  font-weight: 500; transition: all .2s;
}
.pdf-btn.es {
  background: rgba(255,107,53,.1); border: 1px solid var(--orange); color: var(--orange);
}
.pdf-btn.en {
  background: rgba(90,170,255,.1); border: 1px solid var(--blue); color: var(--blue);
}
.pdf-btn:hover { transform: translateY(-2px); opacity: 1; filter: brightness(1.2); }

/* ---- Footer ---- */
.foot {
  text-align: center; padding: 30px 24px; font-size: .72em;
  color: #333; border-top: 1px solid var(--border);
}

/* ---- Responsive ---- */
@media (max-width: 600px) {
  .nav { padding: 0 14px; }
  .nav-links { gap: 12px; }
  .nav-links a { font-size: .75em; }
  .hero { padding: 70px 16px 40px; }
  .cards { grid-template-columns: 1fr; padding: 0 14px; }
}