:root{
  --black: #000000;
  --ink: #111827;
  --muted: #6b7280;

  --sky-50: #f6fbff;
  --sky-100:#eaf6ff;
  --sky-200:#d6eeff;
  --sky-300:#bfe3ff;

  --card: rgba(255,255,255,0.88);
  --card-border: rgba(15, 23, 42, 0.10);

  --primary: #4fa3e3;
  --primary-ink: #ffffff;

  --radius: 14px;
  --shadow-soft: 0 10px 22px rgba(2, 10, 24, 0.06);
}

/* ======================
   GLOBAL
====================== */
body{
  margin: 0;
  color: var(--ink);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI",
               Roboto, "Noto Sans", "Helvetica Neue", Arial;
  font-size: 18px;
  line-height: 1.9;
  background: linear-gradient(
    180deg,
    var(--sky-200) 0%,
    var(--sky-50) 40%,
    #ffffff 100%
  );
}

.container{
  width: 92%;
  max-width: 1080px;
  margin: 0 auto;
}

/* ======================
   HEADER
====================== */
header{
  background: var(--black);
  color: #fff;
  padding: 1.05rem 0;
  position: sticky;
  top: 0;
  z-index: 20;
  box-shadow: 0 8px 20px rgba(0,0,0,0.18);
}

.header-row{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand-link{
  display: flex;
  gap: 0.85rem;
  align-items: center;
  text-decoration: none;
  color: #fff;
}

.logo{
  height: 42px;
  width: auto;
  border-radius: 10px;
}

.brand-title{
  font-weight: 800;
  font-size: 1.05rem;
  line-height: 1.2;
}

.brand-sub{
  font-size: 0.95rem;
  opacity: 0.85;
}

.nav{
  display: flex;
  gap: 0.9rem;
  align-items: center;
  flex-wrap: wrap;
}

.nav a{
  color: rgba(255,255,255,0.92);
  text-decoration: none;
  font-weight: 600;
  padding: 0.35rem 0.45rem;
  border-radius: 10px;
}

.nav a:hover{
  background: rgba(255,255,255,0.08);
}

.nav-cta{
  border: 1px solid rgba(255,255,255,0.25);
  background: rgba(255,255,255,0.06);
}

.lang-select{
  display: flex;
  gap: 0.45rem;
  align-items: center;
}

.lang-select select{
  padding: 0.35rem 0.5rem;
  border-radius: 10px;
  border: 1px solid rgba(255,255,255,0.25);
  background: rgba(255,255,255,0.08);
  color: #fff;
}

/* ======================
   MAIN
====================== */
main{
  padding: 1.8rem 0 3rem;
}

.block{
  padding: 2.4rem 0;
}

.section-card{
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
  padding: 1.6rem 1.4rem;
}

.block-title{
  margin: 0 0 0.75rem;
  font-size: 1.55rem;
  font-weight: 800;
}

.block-subtitle{
  margin: 0 0 1rem;
  font-size: 1.12rem;
  color: var(--muted);
}

/* ======================
   HERO (Academic)
====================== */
.hero{
  padding: 2.8rem 0 2.2rem;
}

.hero .section-card{
  background: linear-gradient(
    135deg,
    #ffffff 0%,
    #eef7ff 100%
  );
}

.hero-grid{
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 2rem;
  align-items: center;
}

.hero-title{
  margin: 0;
  font-size: 2.1rem;
  font-weight: 850;
}

.hero-subtitle{
  margin: 0.6rem 0 1rem;
  font-size: 1.25rem;
  font-weight: 650;
  color: rgba(17,24,39,0.78);
}

.hero-text{
  max-width: 60ch;
  color: rgba(17,24,39,0.86);
}

.hero-actions{
  margin-top: 1.4rem;
  display: flex;
  gap: 0.9rem;
  flex-wrap: wrap;
}

/* ======================
   HERO IMAGE (Integrated)
====================== */
.hero-image-box{
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-image-box::before{
  content: "";
  position: absolute;
  width: 260px;
  height: 260px;
  background: radial-gradient(
    circle,
    rgba(180,220,255,0.35) 0%,
    rgba(180,220,255,0.15) 45%,
    transparent 72%
  );
  z-index: 0;
}

.hero-image-box img{
  position: relative;
  z-index: 1;
  width: 100%;
  height: 300px;
  object-fit: contain;
  filter: saturate(0.88) contrast(0.95);
  opacity: 0.92;
  border-radius: 12px;
}

/* ======================
   BUTTONS
====================== */
.btn-primary,
.btn-secondary{
  display: inline-block;
  padding: 0.75rem 1.05rem;
  border-radius: 12px;
  font-weight: 700;
  text-decoration: none;
}

.btn-primary{
  background: var(--primary);
  color: var(--primary-ink);
}

.btn-secondary{
  background: transparent;
  color: var(--primary);
  border: 1px solid rgba(11,99,206,0.55);
}

/* ======================
   LISTS / COLUMNS
====================== */
.two-cols{
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.4rem;
}

@media (min-width: 920px){
  .two-cols{
    grid-template-columns: 1fr 1fr;
  }
}

.checklist,
.banlist{
  list-style: none;
  padding: 0;
  margin: 0.6rem 0 0;
  line-height: 2.05;
}

/* ======================
   ARTICLES
====================== */
.article-list{
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 1rem;
}

.article-list li{
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 1.1rem;
  box-shadow: var(--shadow-soft);
}

/* ======================
   FOOTER
====================== */
footer{
  background: var(--black);
  color: rgba(255,255,255,0.9);
  padding: 2.6rem 0;
  margin-top: 2.6rem;
}

.footer-grid{
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.4rem;
}

@media (min-width: 860px){
  .footer-grid{
    grid-template-columns: 1.2fr 1fr 1fr;
  }
}

.footer-title{
  font-weight: 800;
  margin-bottom: 0.4rem;
}

.footer-muted{
  color: rgba(255,255,255,0.75);
  font-size: 0.95rem;
  line-height: 1.8;
}

.footer-bottom{
  margin-top: 1.4rem;
  padding-top: 1.2rem;
  border-top: 1px solid rgba(255,255,255,0.14);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  color: rgba(255,255,255,0.7);
}

/* ======================
   MOBILE
====================== */
@media (max-width: 820px){
  body{ font-size: 17px; }

  .hero-grid{
    grid-template-columns: 1fr;
  }

  .hero-image-box{
    order: -1;
  }

  .hero-image-box::before{
    width: 220px;
    height: 220px;
  }

  .hero-image-box img{
    height: 240px;
  }

  .hero-title{
    font-size: 1.9rem;
  }
}
/* ======================
   JOIN FORM – FIX (Academic + Clean)
====================== */
.form-card{
  background: rgba(255,255,255,0.96);
  border: 1px solid rgba(15, 23, 42, 0.10);
  border-radius: 14px;
  box-shadow: 0 10px 22px rgba(2, 10, 24, 0.05);
  padding: 1.4rem;
  margin-top: 1.2rem;
}

.form{
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.95rem;
}

.form label{
  display: block;
  font-weight: 700;
  color: rgba(17,24,39,0.92);
}

.form input[type="text"],
.form input[type="email"],
.form input[type="password"],
.form textarea{
  width: 100%;
  display: block;
  margin-top: 0.4rem;
  padding: 0.85rem 0.9rem;
  border-radius: 12px;
  border: 1px solid rgba(17,24,39,0.18);
  background: #fff;
  box-sizing: border-box;
  font-size: 1rem;
  line-height: 1.6;
}

.form textarea{
  min-height: 140px;
  resize: vertical;
}

.checkbox{
  display: flex;
  gap: 0.7rem;
  align-items: flex-start;
  padding: 0.3rem 0;
}

.checkbox input{
  margin-top: 0.35rem;
}

.warning{
  margin-top: 0.4rem;
  border-radius: 14px;
}

.form button.btn-primary{
  justify-self: start; /* يخلي الزر واضح ومناسب */
  padding: 0.8rem 1.2rem;
}
/* Login compact card */
.form-card--compact{
  max-width: 520px;
  margin-left: auto;
  margin-right: auto;
}
/* ======================
   PAPERS / ARTICLES (Research-style)
====================== */
.papers-header{
  padding: 1.6rem 1.4rem;
}

.papers-subtitle{
  margin: 0.3rem 0 0;
  color: rgba(17,24,39,0.72);
  max-width: 70ch;
}

.papers-grid{
  margin-top: 1.2rem;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 860px){
  .papers-grid{
    grid-template-columns: 1fr 1fr;
  }
}

.paper-card{
  background: rgba(255,255,255,0.92);
  border: 1px solid rgba(15, 23, 42, 0.10);
  border-radius: 14px;
  box-shadow: 0 10px 22px rgba(2, 10, 24, 0.05);
  padding: 1.2rem 1.2rem;
}

.paper-meta{
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.8rem;
  margin-bottom: 0.6rem;
  color: rgba(17,24,39,0.68);
  font-size: 0.95rem;
}

.paper-badge{
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  border: 1px solid rgba(11,99,206,0.22);
  background: rgba(11,99,206,0.08);
  color: rgba(11,99,206,0.95);
  font-weight: 800;
  letter-spacing: 0.3px;
}

.paper-date{
  opacity: 0.85;
}

.paper-title{
  margin: 0.1rem 0 0.55rem;
  font-size: 1.22rem;
  line-height: 1.45;
}

.paper-title a{
  text-decoration: none;
  color: rgba(17,24,39,0.95);
}

.paper-title a:hover{
  text-decoration: underline;
}

.paper-abstract{
  margin: 0;
  color: rgba(17,24,39,0.78);
  line-height: 1.85;
}

.paper-footer{
  margin-top: 0.85rem;
  display: flex;
  justify-content: flex-start;
}

.paper-link{
  text-decoration: none;
  font-weight: 800;
  color: rgba(11,99,206,0.95);
}

.paper-link:hover{
  text-decoration: underline;
}

/* Single paper page */
.paper-shell{
  padding: 1.7rem 1.5rem;
}

.paper-topmeta{
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.8rem;
  color: rgba(17,24,39,0.68);
  font-size: 0.95rem;
}

.paper-h1{
  margin: 0.7rem 0 0.5rem;
  font-size: 2rem;
  line-height: 1.25;
  letter-spacing: 0.2px;
}

.paper-divider{
  height: 1px;
  background: rgba(15, 23, 42, 0.10);
  margin: 1.1rem 0;
}

.paper-content{
  max-width: 75ch; /* قراءة أكاديمية */
}

.paper-content p{
  margin: 0.8rem 0;
}

.paper-content h2, .paper-content h3{
  margin: 1.35rem 0 0.65rem;
  line-height: 1.35;
}

.paper-nav{
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.paper-back{
  text-decoration: none;
  color: rgba(11,99,206,0.95);
  font-weight: 800;
}
.paper-back:hover{
  text-decoration: underline;
}