/* ===== HERO ===== */
.calc-hero {
  padding: 5rem 5%;
  text-align: center;
  background: #f4f7fb;
}

.calc-hero h1 {
  font-size: 2.8rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: #0f172a;
}

.calc-hero h1 span {
  color: #0ea5e9; /* bright professional blue */
}

.calc-hero p {
  max-width: 650px;
  margin: auto;
  color: #475569;
  font-size: 1.05rem;
  line-height: 1.6;
}


/* ===== SECTION ===== */
.calc-section {
  padding: 80px 20px;
  background: #f8fafc;
}

.calc-container {
  max-width: 1100px;
  margin: auto;
  text-align: center;
}

.calc-title {
  font-size: 2.2rem;
  margin-bottom: 20px;
  color: #0f172a;
}


/* ===== SEARCH ===== */
.calc-search {
  width: 100%;
  max-width: 450px;
  padding: 14px 16px;
  border-radius: 10px;
  border: 1px solid #cbd5e1;
  margin-bottom: 30px;
  font-size: 1rem;
  color: #0f172a;
  background: white;
}

.calc-search::placeholder {
  color: #94a3b8;
}


/* ===== FILTER BUTTONS ===== */
.calc-filter {
  margin-bottom: 40px;
}

.calc-btn {
  padding: 10px 18px;
  border-radius: 10px;
  border: 1px solid #cbd5e1;
  background: white;
  margin: 6px;
  cursor: pointer;
  transition: all .25s ease;
  color: #334155;
  font-weight: 500;
}

.calc-btn:hover {
  background: #e2e8f0;
}

.calc-btn.active {
  background: #0ea5e9;
  color: white;
  border-color: #0ea5e9;
}


/* ===== GRID ===== */
.calc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit,minmax(260px,1fr));
  gap: 26px;
}


/* ===== CARD ===== */
.calc-card {
  background: white;
  padding: 26px;
  border-radius: 14px;
  text-decoration: none;
  color: inherit;
  box-shadow: 0 6px 18px rgba(15,23,42,.06);
  transition: all .3s ease;
  border: 1px solid #e2e8f0;
  text-align: left;
}

.calc-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 14px 34px rgba(15,23,42,.08);
}


/* ===== MULTI-COLOR CARD TITLES ===== */
.calc-card:nth-child(4n+1) h3 { color: #0ea5e9; }  /* blue */
.calc-card:nth-child(4n+2) h3 { color: #10b981; }  /* green */
.calc-card:nth-child(4n+3) h3 { color: #f59e0b; }  /* amber */
.calc-card:nth-child(4n+4) h3 { color: #6366f1; }  /* indigo */

.calc-card h3 {
  margin-bottom: 10px;
  font-size: 1.2rem;
}

.calc-card p {
  color: #475569;
  font-size: .96rem;
  line-height: 1.6;
}


/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {

  .calc-hero h1 {
    font-size: 2.2rem;
  }

  .calc-card {
    padding: 22px;
  }

}


/* Partial Derivative Calculator */


.partial-derivative-calculator-section{
  background:#f6f8fb;
  padding:80px 20px;
}

.partial-derivative-calculator-container{
  max-width:780px;
  margin:0 auto;
  font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
  color:#1e293b;
}

.partial-derivative-calculator-title{
  font-size:2.4rem;
  font-weight:700;
  text-align:center;
  margin-bottom:14px;
  letter-spacing:-0.02em;
}

.partial-derivative-calculator-intro{
  text-align:center;
  font-size:1.08rem;
  color:#64748b;
  max-width:620px;
  margin:0 auto 48px;
  line-height:1.7;
}

.partial-derivative-calculator-card{
  background:#ffffff;
  border-radius:18px;
  padding:36px 38px 40px;
  box-shadow:0 20px 50px rgba(15,23,42,.06);
  border:1px solid #eef2f7;
  margin-bottom:48px;
}

.partial-derivative-calculator-label{
  font-weight:600;
  font-size:.95rem;
  color:#334155;
  margin-bottom:8px;
  display:block;
}

.partial-derivative-calculator-input{
  width:100%;
  padding:16px 16px;
  font-size:1rem;
  border-radius:12px;
  border:1px solid #dbe2ea;
  background:#fbfdff;
  transition:.2s ease;
}

.partial-derivative-calculator-input:focus{
  outline:none;
  border-color:#2563eb;
  background:#fff;
  box-shadow:0 0 0 3px rgba(37,99,235,.12);
}

.partial-derivative-calculator-buttons{
  display:flex;
  gap:14px;
  margin-top:26px;
}

.partial-derivative-calculator-btn{
  flex:1;
  padding:15px 0;
  font-size:.95rem;
  font-weight:600;
  border-radius:12px;
  border:none;
  cursor:pointer;
  transition:.18s ease;
}

.partial-derivative-calculator-btn.primary{
  background:#2563eb;
  color:#fff;
  box-shadow:0 6px 16px rgba(37,99,235,.25);
}

.partial-derivative-calculator-btn.primary:hover{
  background:#1e4ed8;
  transform:translateY(-1px);
}

.partial-derivative-calculator-btn.secondary{
  background:#f1f5f9;
  color:#334155;
}

.partial-derivative-calculator-btn.secondary:hover{
  background:#e2e8f0;
}

.partial-derivative-calculator-result{
  margin-top:26px;
  font-size:1.25rem;
  font-weight:600;
  text-align:center;
  color:#059669;
  min-height:28px;
}

.partial-derivative-calculator-content{
  max-width:680px;
  margin:0 auto;
}

.partial-derivative-calculator-content h2{
  font-size:1.45rem;
  margin-top:40px;
  margin-bottom:14px;
  font-weight:650;
  letter-spacing:-0.01em;
}

.partial-derivative-calculator-content p,
.partial-derivative-calculator-content li{
  font-size:1rem;
  line-height:1.75;
  color:#475569;
}

.partial-derivative-calculator-content ul,
.partial-derivative-calculator-content ol{
  padding-left:20px;
  margin-top:10px;
}

.partial-derivative-calculator-cta{
  margin-top:36px;
  padding:20px 22px;
  border-radius:12px;
  background:#f1f5ff;
  border:1px solid #dbeafe;
  font-weight:600;
  color:#1e40af;
}

.partial-derivative-calculator-content h3{
  font-size:1.08rem;
  font-weight:600;
  margin-top:22px;
  margin-bottom:6px;
  color:#1e293b;
}

.partial-derivative-calculator-content h3 + p{
  margin-top:0;
  padding:14px 16px;
  background:#f8fafc;
  border:1px solid #eef2f7;
  border-radius:10px;
  font-size:.98rem;
  line-height:1.65;
}

@media (max-width:640px){
  .partial-derivative-calculator-title{font-size:2rem;}
  .partial-derivative-calculator-card{padding:26px 22px 30px;}
  .partial-derivative-calculator-buttons{flex-direction:column;}
  .partial-derivative-calculator-btn{width:100%;}
}



/* Partial Derivative Calculator */



/* Half Birthday Calculator */


/* ===== SECTION WRAPPER ===== */
.half-birthday-calculator-section{
  background:#f6f8fb;
  padding:80px 20px;
}

/* ===== CONTAINER ===== */
.half-birthday-calculator-container{
  max-width:780px;
  margin:0 auto;
  font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
  color:#1e293b;
}

/* ===== TITLE ===== */
.half-birthday-calculator-title{
  font-size:2.4rem;
  font-weight:700;
  text-align:center;
  margin-bottom:14px;
  letter-spacing:-0.02em;
}

/* ===== INTRO TEXT ===== */
.half-birthday-calculator-intro{
  text-align:center;
  font-size:1.08rem;
  color:#64748b;
  max-width:620px;
  margin:0 auto 48px;
  line-height:1.7;
}

/* ===== TOOL CARD ===== */
.half-birthday-calculator-card{
  background:#ffffff;
  border-radius:18px;
  padding:36px 38px 40px;
  box-shadow:0 20px 50px rgba(15,23,42,.06);
  border:1px solid #eef2f7;
  margin-bottom:48px;
}

/* ===== LABEL ===== */
.half-birthday-calculator-label{
  font-weight:600;
  font-size:.95rem;
  color:#334155;
  margin-bottom:8px;
  display:block;
}

/* ===== INPUT ===== */
.half-birthday-calculator-input{
  width:100%;
  padding:16px 16px;
  font-size:1rem;
  border-radius:12px;
  border:1px solid #dbe2ea;
  background:#fbfdff;
  transition:.2s ease;
}

.half-birthday-calculator-input:focus{
  outline:none;
  border-color:#2563eb;
  background:#fff;
  box-shadow:0 0 0 3px rgba(37,99,235,.12);
}

/* ===== BUTTON GROUP ===== */
.half-birthday-calculator-buttons{
  display:flex;
  gap:14px;
  margin-top:26px;
}

/* ===== BUTTON BASE ===== */
.half-birthday-calculator-btn{
  flex:1;
  padding:15px 0;
  font-size:.95rem;
  font-weight:600;
  border-radius:12px;
  border:none;
  cursor:pointer;
  transition:.18s ease;
}

/* PRIMARY BUTTON */
.half-birthday-calculator-btn.primary{
  background:#2563eb;
  color:#fff;
  box-shadow:0 6px 16px rgba(37,99,235,.25);
}

.half-birthday-calculator-btn.primary:hover{
  background:#1e4ed8;
  transform:translateY(-1px);
}

/* SECONDARY BUTTON */
.half-birthday-calculator-btn.secondary{
  background:#f1f5f9;
  color:#334155;
}

.half-birthday-calculator-btn.secondary:hover{
  background:#e2e8f0;
}

/* ===== RESULT TEXT ===== */
.half-birthday-calculator-result{
  margin-top:26px;
  font-size:1.25rem;
  font-weight:600;
  text-align:center;
  color:#059669;
  min-height:28px;
}

/* ===== CONTENT SECTION ===== */
.half-birthday-calculator-content{
  max-width:680px;
  margin:0 auto;
}

/* HEADINGS */
.half-birthday-calculator-content h2{
  font-size:1.45rem;
  margin-top:40px;
  margin-bottom:14px;
  font-weight:650;
  letter-spacing:-0.01em;
}

/* TEXT */
.half-birthday-calculator-content p,
.half-birthday-calculator-content li{
  font-size:1rem;
  line-height:1.75;
  color:#475569;
}

/* LISTS */
.half-birthday-calculator-content ul,
.half-birthday-calculator-content ol{
  padding-left:20px;
  margin-top:10px;
}

/* CTA BOX */
.half-birthday-calculator-cta{
  margin-top:36px;
  padding:20px 22px;
  border-radius:12px;
  background:#f1f5ff;
  border:1px solid #dbeafe;
  font-weight:600;
  color:#1e40af;
}

/* ===== FAQ BLOCK ===== */

.half-birthday-calculator-content h3{
  font-size:1.08rem;
  font-weight:600;
  margin-top:22px;
  margin-bottom:6px;
  color:#1e293b;
}

.half-birthday-calculator-content h3 + p{
  margin-top:0;
  padding:14px 16px;
  background:#f8fafc;
  border:1px solid #eef2f7;
  border-radius:10px;
  font-size:.98rem;
  line-height:1.65;
}


/* ===== MOBILE ===== */
@media (max-width:640px){

  .half-birthday-calculator-title{
    font-size:2rem;
  }

  .half-birthday-calculator-card{
    padding:26px 22px 30px;
  }

  .half-birthday-calculator-buttons{
    flex-direction:column;
  }

  .half-birthday-calculator-btn{
    width:100%;
  }
}



/* Half Birthday Calculator */








.batting-average-calculator-section{
  background:#f6f8fb;
  padding:80px 20px;
}

/* ===== CONTAINER ===== */
.batting-average-calculator-container{
  max-width:780px;
  margin:0 auto;
  font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
  color:#1e293b;
}

/* ===== TITLE ===== */
.batting-average-calculator-title{
  font-size:2.4rem;
  font-weight:700;
  text-align:center;
  margin-bottom:14px;
  letter-spacing:-0.02em;
}

/* ===== INTRO TEXT ===== */
.batting-average-calculator-intro{
  text-align:center;
  font-size:1.08rem;
  color:#64748b;
  max-width:620px;
  margin:0 auto 48px;
  line-height:1.7;
}

/* ===== TOOL CARD ===== */
.batting-average-calculator-card{
  background:#ffffff;
  border-radius:18px;
  padding:36px 38px 40px;
  box-shadow:0 20px 50px rgba(15,23,42,.06);
  border:1px solid #eef2f7;
  margin-bottom:48px;
}

/* ===== LABEL ===== */
.batting-average-calculator-label{
  font-weight:600;
  font-size:.95rem;
  color:#334155;
  margin-bottom:8px;
  display:block;
}

/* ===== INPUT ===== */
.batting-average-calculator-input{
  width:100%;
  padding:16px 16px;
  font-size:1rem;
  border-radius:12px;
  border:1px solid #dbe2ea;
  background:#fbfdff;
  transition:.2s ease;
}

.batting-average-calculator-input:focus{
  outline:none;
  border-color:#2563eb;
  background:#fff;
  box-shadow:0 0 0 3px rgba(37,99,235,.12);
}

/* ===== BUTTON GROUP ===== */
.batting-average-calculator-buttons{
  display:flex;
  gap:14px;
  margin-top:26px;
}

/* ===== BUTTON BASE ===== */
.batting-average-calculator-btn{
  flex:1;
  padding:15px 0;
  font-size:.95rem;
  font-weight:600;
  border-radius:12px;
  border:none;
  cursor:pointer;
  transition:.18s ease;
}

/* PRIMARY BUTTON */
.batting-average-calculator-btn.primary{
  background:#2563eb;
  color:#fff;
  box-shadow:0 6px 16px rgba(37,99,235,.25);
}

.batting-average-calculator-btn.primary:hover{
  background:#1e4ed8;
  transform:translateY(-1px);
}

/* SECONDARY BUTTON */
.batting-average-calculator-btn.secondary{
  background:#f1f5f9;
  color:#334155;
}

.batting-average-calculator-btn.secondary:hover{
  background:#e2e8f0;
}

/* ===== RESULT TEXT ===== */
.batting-average-calculator-result{
  margin-top:26px;
  font-size:1.25rem;
  font-weight:600;
  text-align:center;
  color:#059669;
  min-height:28px;
}

/* ===== CONTENT SECTION ===== */
.batting-average-calculator-content{
  max-width:680px;
  margin:0 auto;
}

/* HEADINGS */
.batting-average-calculator-content h2{
  font-size:1.45rem;
  margin-top:40px;
  margin-bottom:14px;
  font-weight:650;
  letter-spacing:-0.01em;
}

/* TEXT */
.batting-average-calculator-content p,
.batting-average-calculator-content li{
  font-size:1rem;
  line-height:1.75;
  color:#475569;
}

/* LISTS */
.batting-average-calculator-content ul,
.batting-average-calculator-content ol{
  padding-left:20px;
  margin-top:10px;
}

/* CTA BOX */
.batting-average-calculator-cta{
  margin-top:36px;
  padding:20px 22px;
  border-radius:12px;
  background:#f1f5ff;
  border:1px solid #dbeafe;
  font-weight:600;
  color:#1e40af;
}

/* ===== FAQ BLOCK ===== */

.batting-average-calculator-content h3{
  font-size:1.08rem;
  font-weight:600;
  margin-top:22px;
  margin-bottom:6px;
  color:#1e293b;
}

.batting-average-calculator-content h3 + p{
  margin-top:0;
  padding:14px 16px;
  background:#f8fafc;
  border:1px solid #eef2f7;
  border-radius:10px;
  font-size:.98rem;
  line-height:1.65;
}

/* ===== MOBILE ===== */
@media (max-width:640px){

  .batting-average-calculator-title{
    font-size:2rem;
  }

  .batting-average-calculator-card{
    padding:26px 22px 30px;
  }

  .batting-average-calculator-buttons{
    flex-direction:column;
  }

  .batting-average-calculator-btn{
    width:100%;
  }
}