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

body{
  background:#0f172a;
  color:white;
  min-height:100vh;
}

/* NAVBAR */

nav{
  display:flex;
  justify-content:space-between;
  align-items:center;
  padding:20px 60px;
  background:#111827;
}

.logo{
  font-size:2rem;
  color:#3b82f6;
}

nav ul{
  display:flex;
  list-style:none;
  gap:25px;
}

nav a{
  color:white;
  text-decoration:none;
  transition:0.3s;
}

nav a:hover{
  color:#3b82f6;
}

/* HERO SECTION */

.hero{
  display:flex;
  justify-content:space-between;
  align-items:center;
  padding:80px 60px;
  gap:50px;
}

.hero-text{
  flex:1;
}

.hero-text h2{
  font-size:4rem;
  line-height:1.2;
  margin-bottom:20px;
}

.hero-text p{
  font-size:1.1rem;
  line-height:1.8;
  max-width:600px;
  margin-bottom:30px;
  color:#cbd5e1;
}

.btn{
  display:inline-block;
  background:#3b82f6;
  padding:15px 30px;
  border-radius:12px;
  text-decoration:none;
  color:white;
  transition:0.3s;
}

.btn:hover{
  background:#2563eb;
  transform:translateY(-3px);
}

/* HERO CARD */

.hero-card{
  width:350px;
  background:#1e293b;
  padding:30px;
  border-radius:20px;
  box-shadow:0 0 25px rgba(0,0,0,0.3);
}

.hero-card h3{
  margin-bottom:20px;
  font-size:1.5rem;
}

.feature{
  background:#334155;
  padding:15px;
  margin-bottom:15px;
  border-radius:12px;
}

/* ASSISTANT PAGE */

.assistant-page{
  padding:40px;
  max-width:900px;
  margin:auto;
}

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

.chat-box{
  background:#1e293b;
  height:450px;
  overflow-y:auto;
  padding:20px;
  border-radius:15px;
  margin-bottom:20px;
}

.message{
  padding:15px;
  margin-bottom:15px;
  border-radius:10px;
  max-width:70%;
}

.user{
  background:#3b82f6;
  margin-left:auto;
}

.bot{
  background:#334155;
}

.input-area{
  display:flex;
  gap:10px;
}

.input-area input{
  flex:1;
  padding:15px;
  border:none;
  border-radius:10px;
  outline:none;
}

.input-area button{
  padding:15px 25px;
  border:none;
  border-radius:10px;
  background:#3b82f6;
  color:white;
  cursor:pointer;
}

/* MOBILE */

@media(max-width:900px){

  nav{
    flex-direction:column;
    gap:20px;
    padding:20px;
  }

  .hero{
    flex-direction:column;
    text-align:center;
    padding:50px 20px;
  }

  .hero-text h2{
    font-size:3rem;
  }

  .hero-card{
    width:100%;
  }
}

/* FLASHCARDS */

.flashcards-page{
  padding:50px;
  text-align:center;
}

.flashcards-page h2{
  font-size:3rem;
  margin-bottom:10px;
}

.flash-info{
  color:#cbd5e1;
  margin-bottom:40px;
}

.cards-container{
  display:flex;
  justify-content:center;
  gap:30px;
  flex-wrap:wrap;
}

.flashcard{
  width:250px;
  height:180px;
  perspective:1000px;
  cursor:pointer;
}

.card-inner{
  width:100%;
  height:100%;
  position:relative;
  transition:transform 0.7s;
  transform-style:preserve-3d;
}

.flashcard.flipped .card-inner{
  transform:rotateY(180deg);
}

.card-front,
.card-back{
  position:absolute;
  width:100%;
  height:100%;
  border-radius:20px;
  display:flex;
  justify-content:center;
  align-items:center;
  text-align:center;
  padding:20px;
  backface-visibility:hidden;
  font-size:1.1rem;
}

.card-front{
  background:#1e293b;
}

.card-back{
  background:#3b82f6;
  transform:rotateY(180deg);
}

/* QUIZ PAGE */

.quiz-page{
  padding:50px;
  text-align:center;
}

.quiz-page h2{
  font-size:3rem;
  margin-bottom:40px;
}

.quiz-box{
  background:#1e293b;
  max-width:700px;
  margin:auto;
  padding:40px;
  border-radius:20px;
}

.quiz-box h3{
  margin-bottom:30px;
  font-size:1.5rem;
}

.answers{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:20px;
}

.answers button{
  padding:18px;
  border:none;
  border-radius:12px;
  background:#334155;
  color:white;
  cursor:pointer;
  transition:0.3s;
  font-size:1rem;
}

.answers button:hover{
  background:#3b82f6;
}

#result{
  margin-top:30px;
  font-size:1.2rem;
  font-weight:bold;
}

#nextBtn{
  margin-top:25px;
  padding:15px 25px;
  border:none;
  border-radius:12px;
  background:#3b82f6;
  color:white;
  cursor:pointer;
  display:none;
}

/* TOPIC INPUT */

.topic-box{
  display:flex;
  justify-content:center;
  gap:15px;
  margin-bottom:40px;
  flex-wrap:wrap;
}

.topic-box input{
  padding:15px;
  width:300px;
  border:none;
  border-radius:12px;
  outline:none;
}

.topic-box button{
  padding:15px 25px;
  border:none;
  border-radius:12px;
  background:#3b82f6;
  color:white;
  cursor:pointer;
}

.topic-box select{
  padding:15px;
  border:none;
  border-radius:12px;
  outline:none;
}
/* SMOOTH EFFECTS */

html{
  scroll-behavior:smooth;
}

body{
  background:
  radial-gradient(circle at top,
  #16213e,
  #0f172a 60%);
}

/* GLOW */

.hero-card,
.quiz-box,
.chat-box,
.flashcard{
  box-shadow:
  0 0 20px rgba(59,130,246,0.15);
}

/* HOVER EFFECTS */

.flashcard:hover,
.hero-card:hover,
.quiz-box:hover{
  transform:translateY(-5px);
  transition:0.3s;
}

/* BUTTON EFFECT */

button,
.btn{
  transition:0.3s;
}

button:hover,
.btn:hover{
  transform:scale(1.03);
}

/* INPUTS */

input,
select{
  background:#1e293b;
  color:white;
}

/* SCROLLBAR */

::-webkit-scrollbar{
  width:10px;
}

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

::-webkit-scrollbar-thumb{
  background:#3b82f6;
  border-radius:20px;
}

/* FOOTER */

footer{
  text-align:center;
  padding:30px;
  margin-top:50px;
  color:#94a3b8;
}

.loading{
  text-align:center;
  color:#94a3b8;
  margin:10px 0;
  font-style:italic;
}

.hidden{
  display:none;
}

/* =========================
   NEW HOMEPAGE
========================= */

.hero{
  min-height:90vh;
  display:flex;
  justify-content:space-between;
  align-items:center;
  padding:80px 8%;
  gap:60px;
}

.hero-left{
  flex:1;
}

.hero-right{
  flex:1;
  display:flex;
  justify-content:center;
}

.tag{
  display:inline-block;
  background:rgba(59,130,246,0.15);
  color:#60a5fa;
  padding:10px 18px;
  border-radius:999px;
  font-size:0.85rem;
  margin-bottom:25px;
  border:1px solid rgba(96,165,250,0.2);
}

.hero-left h1{
  font-size:4.5rem;
  line-height:1.1;
  margin-bottom:25px;
}

.hero-left p{
  font-size:1.1rem;
  line-height:1.8;
  color:#cbd5e1;
  max-width:600px;
  margin-bottom:35px;
}

.hero-buttons{
  display:flex;
  gap:20px;
  flex-wrap:wrap;
}

/* BUTTONS */

.btn{
  background:#3b82f6;
  color:white;
  padding:15px 28px;
  border-radius:14px;
  text-decoration:none;
  font-weight:500;
  transition:0.3s;
}

.btn:hover{
  transform:translateY(-3px);
}

.secondary-btn{
  background:#1e293b;
  border:1px solid rgba(255,255,255,0.08);
}

/* PREVIEW CARD */

.preview-card{
  width:370px;
  background:#1e293b;
  border-radius:24px;
  padding:25px;
  border:1px solid rgba(255,255,255,0.06);
  box-shadow:0 0 30px rgba(59,130,246,0.12);
}

.preview-top{
  font-weight:600;
  margin-bottom:25px;
  color:#60a5fa;
}

.preview-chat{
  display:flex;
  flex-direction:column;
  gap:18px;
}

.bot-preview,
.user-preview{
  padding:16px;
  border-radius:16px;
  line-height:1.6;
}

.bot-preview{
  background:#334155;
}

.user-preview{
  background:#3b82f6;
}

/* FEATURES SECTION */

.features-section{
  padding:100px 8%;
}

.features-section h2{
  text-align:center;
  font-size:2.7rem;
  margin-bottom:60px;
}

.features-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit, minmax(250px,1fr));
  gap:30px;
}

.feature-card{
  background:#1e293b;
  padding:35px;
  border-radius:24px;
  transition:0.3s;
  border:1px solid rgba(255,255,255,0.05);
}

.feature-card:hover{
  transform:translateY(-6px);
}

.feature-icon{
  font-size:2.5rem;
  margin-bottom:20px;
}

.feature-card h3{
  margin-bottom:15px;
  font-size:1.4rem;
}

.feature-card p{
  color:#cbd5e1;
  line-height:1.7;
}

/* CTA SECTION */

.cta-section{
  padding:100px 8%;
  text-align:center;
}

.cta-section h2{
  font-size:3rem;
  margin-bottom:20px;
}

.cta-section p{
  color:#cbd5e1;
  margin-bottom:35px;
  font-size:1.1rem;
}

/* FOOTER */

footer{
  padding:35px;
  text-align:center;
  color:#94a3b8;
  border-top:1px solid rgba(255,255,255,0.05);
  margin-top:50px;
}

/* MOBILE */

@media(max-width:950px){

  .hero{
    flex-direction:column;
    text-align:center;
    padding-top:60px;
  }

  .hero-left h1{
    font-size:3.2rem;
  }

  .hero-left p{
    margin:auto;
    margin-bottom:35px;
  }

  .hero-buttons{
    justify-content:center;
  }

  .preview-card{
    width:100%;
    max-width:400px;
  }

  nav{
    flex-direction:column;
    gap:20px;
    padding:20px;
  }

  nav ul{
    flex-wrap:wrap;
    justify-content:center;
  }

}

/* ABOUT PAGE */

.about-page{
  padding:80px 8%;
  text-align:center;
}

.about-hero{
  margin-bottom:60px;
}

.about-hero h2{
  font-size:3rem;
  margin-bottom:20px;
}

.subtitle{
  max-width:700px;
  margin:auto;
  line-height:1.8;
  color:#cbd5e1;
}

/* ABOUT GRID */

.about-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit, minmax(280px,1fr));
  gap:30px;
  margin-top:40px;
}

.about-card{
  background:#1e293b;
  padding:35px;
  border-radius:24px;
  border:1px solid rgba(255,255,255,0.05);
  transition:0.3s;
}

.about-card:hover{
  transform:translateY(-5px);
}

.about-card h3{
  margin-bottom:20px;
  font-size:1.5rem;
}

.about-card p,
.about-card li{
  color:#cbd5e1;
  line-height:1.8;
}

.about-card ul{
  list-style:none;
  padding:0;
}

/* QUOTE */

.about-footer-note{
  margin-top:70px;
  font-size:1.2rem;
  color:#94a3b8;
  font-style:italic;
}

.message{
  line-height:1.8;
  white-space:normal;
}

.message strong{
  color:#60a5fa;
}