/* Main container */
:root{
  --kirmizi: #b31b1b;    /* koyu kırmızı, eski usul */
  --kirmizi-acik: #e04b4b;
  --beyaz: #fffdf6;      /* hafif kremimsi beyaz, eski kağıt hissi */
  --gri: #6b6863;
  --golge: rgba(0,0,0,0.14);
  --font-base: "Georgia", "Times New Roman", serif;
}

.content {
  display: flex;
  flex-direction: column;
  align-items: flex-start; /* Kartlar sola hizalı */
  min-height: 100vh;
  padding-left: 2rem;
  font-family: 'Merriweather', serif;
  background: transparent;
  color: #222;
}

.hero-text {
  width: 100%;
  text-align: center; /* Başlık ortalanmış */
  margin-bottom: 1.5rem;
}

.hero-text .welcome {
  font-size: 1.6rem;
  font-weight: 500;
  color: #b30000;
  margin-bottom: 0.5rem;
  font-family: 'Georgia', serif;
}

.logo-box {
  display: inline-block;
  padding: 1rem 2.5rem;
  background: transparent;
  border: 3px solid #b30000;
  color: #b30000;
  font-size: 2.4rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  border-radius: 12px;
  box-shadow: 0 4px 10px rgba(179,0,0,0.2);
  margin-bottom: 1.5rem;
  text-align: center; /* yazı da ortalanmış */
}

.logo-box::before {
  content: "rumiakademi";
  display: inline-block;
}

/* Intro paragraph */
.intro-text {
  font-size: 1.1rem;
  line-height: 1.8;
  width: 100%; /* Yatay olarak yayılıyor */
  text-align: justify; /* soldan sağa yayılmış */
  margin-bottom: 2.5rem;
  color: #333;
  font-family: 'Merriweather', serif;
}


/* Responsive design for smaller screens */
.topic-buttons{
  display:flex;
  gap:1rem;
  margin-top:1rem;
  flex-wrap:wrap;
  align-items:center;
}

/* düğmeler: eski usul, biraz kabartma, yuvarlak uçlar */
.topic-btn{
  background: linear-gradient(180deg, var(--beyaz) 0%, #f7efe6 100%);
  color: var(--kirmizi);
  border: 1px solid rgba(179,27,27,0.25);
  padding: .55rem 1rem;
  font-family: var(--font-base);
  font-size: .95rem;
  letter-spacing: .02em;
  border-radius: 999px;
  position: relative;
  box-shadow:
    0 2px 0 rgba(255,255,255,0.6) inset,
    0 6px 18px var(--golge);
  transition: transform .18s ease, box-shadow .18s ease;
  outline: none;
}

/* hafif yükselme hissi */
.topic-btn:hover{
  transform: translateY(-3px);
  box-shadow:
    0 6px 0 rgba(255,255,255,0.6) inset,
    0 12px 26px rgba(0,0,0,0.18);
}

/* tıklanınca bastırma hissi */
.topic-btn:active{
  transform: translateY(0);
  box-shadow:
    0 1px 0 rgba(255,255,255,0.6) inset,
    0 4px 10px rgba(0,0,0,0.12);
}

/* alt çizgi göstergesi (aktif düğme) */
.topic-btn.active{
  color: #fff;
  background: linear-gradient(180deg, var(--kirmizi) 0%, var(--kirmizi-acik) 100%);
  border-color: rgba(255,255,255,0.08);
}

/* aktif göstergesi için ince çizgi animasyonu */
.topic-btn.active::after{
  content: "";
  position: absolute;
  left: 18%;
  right: 18%;
  bottom: -10px;
  height: 6px;
  border-radius: 6px;
  background: radial-gradient(closest-side, rgba(255,255,255,0.18), rgba(255,255,255,0));
  box-shadow: 0 2px 8px rgba(179,27,27,0.28);
  transform: translateY(0);
  animation: pulseUnderline 1800ms infinite ease-in-out;
}

/* aktif olmayan düğmelerin alt gölgesi (ince) */
.topic-btn::before{
  content: "";
  position: absolute;
  left: 18%;
  right: 18%;
  bottom: -8px;
  height: 4px;
  border-radius: 6px;
  background: rgba(0,0,0,0.03);
  transition: opacity .25s ease;
  opacity: 0;
}
.topic-btn:hover::before{ opacity: 1; }

@keyframes pulseUnderline{
  0%{ transform: translateY(0) scaleX(0.95); opacity: .9; }
  50%{ transform: translateY(2px) scaleX(1.05); opacity: .7; }
  100%{ transform: translateY(0) scaleX(0.95); opacity: .9; }
}

/* bölüm kartları: eski kağıt, iç rahatlatan gölgeler */
.topic-section{
  display:none; /* JS ile gösterilecek */
  width: 95%;
  margin-top:1rem;
  background: linear-gradient(180deg, rgba(255,250,245,1) 0%, var(--beyaz) 100%);
  border: 1px solid rgba(107,104,99,0.12);
  padding: 1.25rem;
  border-radius: 12px;
  font-family: var(--font-base);
  color: #2b2a28;
  box-shadow:
    0 6px 22px rgba(0,0,0,0.08),
    0 1px 0 rgba(255,255,255,0.9) inset;
  transform-origin: top center;
  transform: translateY(8px) scale(.995);
  transition: opacity .36s ease, transform .36s ease, box-shadow .36s ease;
  opacity: 0;
}

/* açıkken görünür kıl */
.topic-section.show{
  display:block;
  opacity: 1;
  transform: translateY(0) scale(1);
}

/* başlık görünüşü: eski yazı hissi */
.topic-section h3{
  margin: 0 0 .5rem 0;
  font-size: 1.2rem;
  letter-spacing: .01em;
  color: var(--kirmizi);
  text-shadow: 0 1px 0 rgba(255,255,255,0.6);
}

/* içerik metni */
.topic-section p{
  margin: 0;
  line-height: 1.65;
  color: var(--gri);
  font-size: .98rem;
}

/* ince süs çizgisi üstte */
.topic-section::before{
  content: "";
  display:block;
  height:6px;
  margin-bottom: .75rem;
  border-radius: 6px;
  background: linear-gradient(90deg, rgba(179,27,27,0.18), rgba(179,27,27,0));
  opacity: .9;
}

/* küçük ekranlarda düğmeler tam genişlikte blok haline gelir */
@media (max-width:640px){
  .topic-buttons{ gap:.6rem; }
  .topic-btn{ flex: 1 1 auto; min-width: 0; text-align:center; padding:.6rem .75rem; }
  .topic-btn::after{ left: 12%; right: 12%; }
}

/* erişilebilirlik: eğer kullanıcı hareketten kaçınıyorsa, hareketleri azalt */
@media (prefers-reduced-motion: reduce){
  .topic-btn, .topic-section{ transition: none; animation: none; transform: none; }
}


/*********************************************************************************************/
/* Research Container Start */
/*********************************************************************************************/
/* Genel bölüm kutusu */
.research-container{
  width: 95%;
  background: linear-gradient(180deg, rgba(255,250,245,0.7), rgba(255,255,255,0.3));
  border: 1px solid rgba(0,0,0,0.05);
  border-radius: 14px;
  padding: 1.5rem 1.8rem;
  font-family: var(--font-base);
  color: #2b2a28;
  box-shadow: 0 8px 24px rgba(0,0,0,0.06);
  backdrop-filter: blur(2px);
  margin-bottom: 2rem;
}

.research-container h2{
  font-family: var(--font-base);
  color: var(--kirmizi);
  letter-spacing: .02em;
  margin: 0 0 .5rem 0;
  text-shadow: 0 1px 0 rgba(255,255,255,0.6);
}

/* Alan butonları (Math, Physics, ...) */
.research-field-btn{
  background: linear-gradient(180deg, var(--beyaz) 0%, #f7efe6 100%);
  color: var(--kirmizi);
  border: 1px solid rgba(179,27,27,0.25);
  padding: .55rem 1rem;
  font-family: var(--font-base);
  font-size: .95rem;
  letter-spacing: .02em;
  border-radius: 999px;
  position: relative;
  box-shadow:
    0 2px 0 rgba(255,255,255,0.6) inset,
    0 6px 18px var(--golge);
  transition: transform .18s ease, box-shadow .18s ease;
}

.research-field-btn:hover{
  transform: translateY(-3px);
  box-shadow:
    0 6px 0 rgba(255,255,255,0.6) inset,
    0 12px 26px rgba(0,0,0,0.18);
}

.research-field-btn:active{
  transform: translateY(0);
}

.research-field-btn.active{
  color: #fff;
  background: linear-gradient(180deg, var(--kirmizi) 0%, var(--kirmizi-acik) 100%);
  border-color: rgba(255,255,255,0.08);
}

.research-field-btn.active::after{
  content: "";
  position: absolute;
  left: 18%;
  right: 18%;
  bottom: -10px;
  height: 6px;
  border-radius: 6px;
  background: radial-gradient(closest-side, rgba(255,255,255,0.18), rgba(255,255,255,0));
  box-shadow: 0 2px 8px rgba(179,27,27,0.28);
  animation: pulseUnderline 1800ms infinite ease-in-out;
}

/* Araştırma alanı bölüm kartları (Math Research Ideas vs...) */
.research-field-section{
  display:none;
  opacity: 0;
  margin-top: 2rem;
  background: linear-gradient(180deg, rgba(255,250,245,1) 0%, var(--beyaz) 100%);
  border: 1px solid rgba(107,104,99,0.12);
  padding: 1.25rem;
  border-radius: 12px;
  font-family: var(--font-base);
  color: #2b2a28;
  box-shadow: 0 6px 22px rgba(0,0,0,0.08);
  transform-origin: top center;
  transform: translateY(12px) scale(.985);
  transition: opacity .36s ease, transform .36s ease;
}

.research-field-section.show{
  display:block;
  opacity: 1;
  transform: translateY(0) scale(1);
}

.research-field-section::before{
  content:"";
  display:block;
  height:6px;
  margin-bottom: 1rem;
  border-radius: 6px;
  background: linear-gradient(90deg, rgba(179,27,27,0.18), rgba(179,27,27,0));
}

/* Alt seviye düğmeleri (High School – University – Advanced) */
.level-btn{
  background: linear-gradient(180deg, var(--beyaz) 0%, #fcf5ea 100%);
  color: var(--kirmizi);
  border: 1px solid rgba(179,27,27,0.25);
  padding: .45rem .9rem;
  font-family: var(--font-base);
  font-size: .88rem;
  border-radius: 999px;
  transition: transform .18s ease, box-shadow .18s ease;
  box-shadow:
    0 2px 0 rgba(255,255,255,0.6) inset,
    0 6px 18px rgba(0,0,0,0.1);
}

.level-btn:hover{
  transform: translateY(-2px);
}

.level-btn.active{
  color: #fff;
  background: linear-gradient(180deg, var(--kirmizi), var(--kirmizi-acik));
}

/* İç seviyeler (HS, UNI, ADV) */
.level-section{
  display:none;
  opacity:0;
  transform: translateY(8px) scale(.99);
  transition: opacity .32s ease, transform .32s ease;
  padding: 1rem 1.2rem;
}

.level-section.show{
  display:block;
  opacity:1;
  transform: translateY(0) scale(1);
}

/* Animasyon */
@keyframes pulseUnderline{
  0%{ transform: translateY(0) scaleX(0.95); opacity: .9; }
  50%{ transform: translateY(2px) scaleX(1.05); opacity: .7; }
  100%{ transform: translateY(0) scaleX(0.95); opacity: .9; }
}

/* Mobil uyum */
@media (max-width:640px){
  .research-field-btn,
  .level-btn{ flex:1 1 auto; text-align:center; }
}

/* Hareket azaltma */
@media (prefers-reduced-motion: reduce){
  .research-field-section,
  .level-section,
  .research-field-btn,
  .level-btn{ transition:none; animation:none; }
}
/*********************************************************************************************/
/* Research Container End */
/*********************************************************************************************/
/*********************************************************************************************/
/* Articles Start */
/*********************************************************************************************/

/* --- Independent Research Section --- */
.independent-research-section {
  width: 95%;
  background: linear-gradient(180deg, rgba(255,250,245,0.8), #fffdf6);
  border: 1px solid rgba(179,27,27,0.12);
  border-radius: 14px;
  padding: 2rem 1.8rem;
  font-family: "Georgia", "Times New Roman", serif;
  color: #2b2a28;
  box-shadow: 0 8px 22px rgba(0,0,0,0.07);
  margin-bottom: 3rem;
}

.independent-research-section h2 {
  color: #b31b1b;
  letter-spacing: .02em;
  text-shadow: 0 1px 0 rgba(255,255,255,0.6);
  margin-bottom: 1rem;
}

.research-article-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.research-article-card {
  background: #fffdf6;
  border: 1px solid rgba(179,27,27,0.15);
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: 0 6px 18px rgba(0,0,0,0.06);
  transition: transform .18s ease, box-shadow .18s ease;
  cursor: default;
}

.research-article-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 28px rgba(0,0,0,0.12);
}

.research-article-card h3 {
  margin: 0 0 .5rem 0;
  color: #b31b1b;
  font-size: 1.2rem;
}

.research-article-card p {
  margin: 0 0 .5rem 0;
  line-height: 1.55;
}

.research-article-card div {
  font-size: 0.9rem;
  opacity: 0.7;
}

/* Mobil uyumlu */
@media (max-width:640px){
  .research-article-card {
      padding: 1.2rem;
  }
}
/*********************************************************************************************/
/* Articles End */
/*********************************************************************************************/

@media (max-width: 768px) {
  .content {
    align-items: center;
    padding: 0 1rem;
  }

  .hero-text {
    margin-bottom: 1.2rem;
  }

  .hero-text .welcome {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.6rem;
  }

  .logo-box {
    padding: 0.6rem 1.4rem;
    border: 2px solid #b30000;
    font-size: 1.5rem;
    letter-spacing: 1px;
    border-radius: 10px;
    box-shadow: 0 3px 8px rgba(179,0,0,0.15);
    margin-bottom: 1rem;
  }

  .intro-text {
    text-align: center;
    font-size: 1rem;
    line-height: 1.6;
    padding: 0 0.5rem;
  }

}