/* =========================
STYLE.CSS
========================= */

@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700;800&display=swap');

*{
  margin:0;
  padding:0;
  box-sizing:border-box;
  font-family:'Poppins',sans-serif;
  scroll-behavior:smooth;
}

body{
  background:
    linear-gradient(rgba(6,10,25,0.88),rgba(6,10,25,0.94)),
    url('https://images.unsplash.com/photo-1516321318423-f06f85e504b3?q=80&w=2070&auto=format&fit=crop');
  background-size:cover;
  background-position:center;
  background-attachment:fixed;
  color:white;
  min-height:100vh;
  overflow-x:hidden;
}

/* HEADER */
.header{
  position:sticky;
  top:0;
  z-index:999;
  background:rgba(18,24,39,0.96);
  backdrop-filter:blur(18px);
  border-bottom:1px solid rgba(255,255,255,0.08);
}

.navbar{
  max-width:1280px;
  margin:auto;
  padding:24px 36px;
  display:flex;
  justify-content:space-between;
  align-items:center;
}

.logo{
  text-decoration:none;
  color:#fff;
  font-size:30px;
  font-weight:800;
}

.logo span{
  color:#38bdf8;
}

.nav-links{
  display:flex;
  align-items:center;
  gap:14px;
}

.nav-btn{
  text-decoration:none;
  color:#e5e7eb;
  padding:12px 24px;
  border-radius:999px;
  font-weight:700;
  background:rgba(255,255,255,0.07);
  border:1px solid rgba(255,255,255,0.14);
  transition:0.3s ease;
}

.nav-btn:hover,
.nav-btn.active{
  color:#06121f;
  background:linear-gradient(135deg,#38bdf8,#2563eb);
  box-shadow:0 10px 25px rgba(56,189,248,0.35);
  transform:translateY(-2px);
}

/* SECTION */
.notes-section{
  width:90%;
  max-width:1280px;
  margin:auto;
  padding:90px 0;
}

.notes-section h1{
  text-align:center;
  font-size:48px;
  margin-bottom:55px;
  font-weight:800;
  color:#38bdf8;
}

/* GRID */
.notes-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(280px,1fr));
  gap:35px;
}

/* CARD */
.note-card{
  background:rgba(30,41,59,0.92);
  border:1px solid #334155;
  border-radius:24px;
  padding:32px;
  transition:0.4s ease;
  position:relative;
  overflow:hidden;
  box-shadow:0 10px 25px rgba(0,0,0,0.3);
}

.note-card::before{
  content:'';
  position:absolute;
  width:220px;
  height:220px;
  background:rgba(37,99,235,0.22);
  border-radius:50%;
  top:-120px;
  right:-120px;
  pointer-events:none;
}

.note-card:hover{
  transform:translateY(-10px);
  border-color:#38bdf8;
  box-shadow:0 15px 35px rgba(56,189,248,0.3);
}

.note-card h2{
  color:#38bdf8;
  margin-bottom:15px;
  font-size:28px;
  line-height:1.4;
}

.note-card p{
  color:#cbd5e1;
  line-height:1.8;
  margin-bottom:25px;
  font-size:15px;
}

.note-card a{
  display:inline-block;
  padding:13px 24px;
  background:#38bdf8;
  color:#020617;
  text-decoration:none;
  border-radius:12px;
  font-weight:700;
  transition:0.3s;
  position:relative;
  z-index:2;
}

.note-card a:hover{
  background:#fff;
  transform:scale(1.05);
}

/* BRANCH / YEAR / SUBJECT GRID */
.branch-grid,
.year-grid,
.subject-grid,
.unit-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(220px,1fr));
  gap:25px;
  padding:40px;
}

.branch-card,
.year-card,
.subject-card,
.unit-grid a{
  background:rgba(30,41,59,0.92);
  padding:30px;
  border-radius:18px;
  text-align:center;
  text-decoration:none;
  font-size:22px;
  font-weight:700;
  color:#38bdf8;
  border:1px solid #334155;
  box-shadow:0 10px 25px rgba(0,0,0,0.25);
  transition:0.3s;
}

.branch-card:hover,
.year-card:hover,
.subject-card:hover,
.unit-grid a:hover{
  transform:translateY(-6px);
  background:#2563eb;
  color:white;
}

/* SCROLLBAR */
::-webkit-scrollbar{
  width:10px;
}

::-webkit-scrollbar-track{
  background:#0f172a;
}

::-webkit-scrollbar-thumb{
  background:#2563eb;
  border-radius:20px;
}

/* MOBILE */
@media(max-width:768px){
  .navbar{
    padding:18px 20px;
    flex-direction:column;
    gap:15px;
  }

  .logo{
    font-size:24px;
  }

  .nav-links{
    width:100%;
    justify-content:center;
    flex-wrap:wrap;
  }

  .nav-btn{
    padding:10px 16px;
    font-size:14px;
  }

  .notes-section{
    padding:60px 0;
  }.nav-links {
    display: flex;
    gap: 15px;
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: #ffffff;
    padding: 12px 28px;
    border-radius: 50px;
    background: rgba(255,255,255,0.08);
    border: 1px solid rgba(255,255,255,0.15);
    transition: all 0.3s ease;
    font-weight: 600;
}

.nav-links a:hover {
    transform: translateY(-2px);
    background: rgba(59,130,246,0.2);
}

.nav-links a.active {
    background: linear-gradient(135deg, #3b82f6, #60a5fa);
    color: #fff;
    box-shadow: 0 0 25px rgba(59,130,246,0.5);
}

  .notes-section h1{
    font-size:36px;
  }

  .note-card{
    padding:25px;
  }

  .branch-grid,
  .year-grid,
  .subject-grid,
  .unit-grid{
    padding:25px;
  }
}

.iot-header{
    display:flex;
    justify-content:space-between;
    align-items:center;
}

.unit-badge{
    padding:10px 18px;
    border-radius:30px;
    background:rgba(59,130,246,0.15);
    color:#93c5fd;
    border:1px solid rgba(59,130,246,0.4);
}

.hero{
    text-align:center;
    padding:80px 20px 40px;
}

.hero-tag{
    display:inline-block;
    padding:10px 18px;
    border-radius:30px;
    background:rgba(168,85,247,0.15);
    color:#d8b4fe;
    margin-bottom:20px;
}

.hero h1{
    font-size:58px;
    margin-bottom:15px;
    background:linear-gradient(135deg,#fff,#60a5fa,#c084fc);
    -webkit-background-clip:text;
    -webkit-text-fill-color:transparent;
}

.hero p{
    max-width:800px;
    margin:auto;
    color:#cbd5e1;
}

.card-icon{
    font-size:42px;
    margin-bottom:18px;
}

.topics{
    width:90%;
    max-width:1200px;
    margin:60px auto;
}

.topics h2{
    text-align:center;
    margin-bottom:30px;
}

.topics-grid{
    display:grid;
    grid-template-columns:repeat(auto-fit,minmax(220px,1fr));
    gap:16px;
}

.topic-item{
    padding:16px;
    border-radius:14px;
    background:rgba(255,255,255,0.06);
    border:1px solid rgba(255,255,255,0.08);
    transition:.3s;
}

.topic-item:hover{
    transform:translateY(-5px);
    border-color:#60a5fa;
}