/* -------- Global Reset -------- */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
  transition: all 0.3s ease;
}

/* -------- Global Variables -------- */
:root {
  --white: #fff;
  --text-color: #000000;
  --primary-color: #000;
  --secondary-color: #272B2F;
  --ui-bg: #fff;
}

/* -------- Page Layout Setup -------- */

body.locked #mainProgramContent { display: none; }
#lockOverlay {
  position: fixed;
  top: 0; 
  left: 0; 
  width: 100%; 
  height: 100%;
  background: white; 
  color: black;
  display: flex; 
  text-align: center;
  justify-content: center; 
  align-items: center;
  flex-direction: column; 
  font-family: 'Courier New';
  z-index: 9999;
}

#lockOverlay h3{
  margin-bottom: 1.5rem;
}

.lockInput {
      padding: 0.5rem;
      font-size: 1rem;
      margin-top: 2rem;
      margin-bottom: 2rem;
    }
    
.lockButton {
      padding: 0.5rem 1rem;
      font-size: 1rem;
      margin-top: 0.5rem;
    }

html, body {
  height: 100%;
}

body {
  background-color: var(--ui-bg);
  color: var(--text-color);
}

.wrapper {
  min-height: 100%;
  display: flex;
  flex-direction: column;
}

.project-logo{
  width: 46x;
  height: 46px;
}

button{
  background-color: var(--primary-color);
  color: var(--white);
  font-size: 18px;
  height: 50px;
  width: 200px;
  border: none;
  padding: 0.6rem 1.2rem;
  border-radius: 6px;
  margin-bottom: 20px;
  cursor: pointer;
}

button:hover{
  background: var(--secondary-color)
}

input{
  padding: 0.6rem;
  margin: 0.3rem 0;
  border: 1px solid #ccc;
  border-radius: 8px;
  font-size: 1rem;
  background: var(--light-bg);
  color: var(--black);
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.1);
  transition: border-color 0.3s, box-shadow 0.3s;
}

/* -------- Navigation Bar -------- */
nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 70px;
  background: var(--primary-color);
  box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
  z-index: 1000;
}

.navigation-bar {
  max-width: 1300px;
  height: 100%;
  margin: auto;
  padding: 0 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.navigation-bar a {
  color: var(--white);
  text-decoration: none;
  font-size: 18px;
  opacity: 0.75;
}

.navigation-bar a:hover,
.navigation-bar a.active-nav {
  opacity: 1;
}

.title-page-area {
  font-size: 30px;
  font-weight: 600;
  opacity: 1;
  display: flex;
  align-items: center;
  gap: 10px;
  color: white;
  cursor: pointer;
  user-select: none;
}

.page-logo {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--secondary-color);
}

#titleLink{
  opacity: 1.0;
}

/* -------- Appearance Area Style -------- */
.appearance-area {
  display: flex;
  align-items: center;
}

.dark-mode-btn {
  width: 50px;
  height: 50px;
  background: var(--secondary-color);
  color: var(--white);
  border-radius: 6px;
  font-size: 20px;
  text-align: center;
  line-height: 50px;
  cursor: pointer;
  margin-left: 10px;
  opacity: 0.8;
}

.dark-mode-btn:hover {
  opacity: 1;
}

/* -------- Page Content Style -------- */
.content {
  flex: 1;
  padding-top: 50px;
}

.page-content h1 {
  font-size: 35px;
}

/* -------- Content Links Style -------- */

.content a {
  font-size: 20px;
  padding: 12px 20px;
  background: var(--primary-color);
  color: var(--white);
  border-radius: 6px;
  text-decoration: none;
  text-align: center;
  align-items: center;
  gap: 8px;
}

.content a:hover {
  background: var(--secondary-color);
}

/* -------- Main Section Style -------- */
.page-content {
  margin-top: 70px;
  padding: 0 60px;
  background: var(--ui-bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  margin-bottom: 40px;
}

.color-text {
  color: var(--primary-color);
}

.page-content p {
  font-size: 18px;
  max-width: 700px;
  margin: 20px 0 30px;
}

/* -------- Main UI Style -------- */

.mainMenu, .calculatorMenu, .lensTranspositionUI, .contactLensParameterMenu, .effectivePowerUI, .sphericalEquivalentUI, .baseCurveUI, .formulaMenu, .lensTranspositionFormula, .contactLensParameterFormula {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

.lensTranspositionUI{
  align-items: center;
}

.functionBtn{
    width: 300px;
}

.uiSelect {
  height: 50px;
  font-size: 16px;
  text-align: center;
  padding: 0 15px;
  border-radius: 6px;
  border: 1px solid gray;
  background-color: var(--ui-bg);
  color: var(--text-color);
  cursor: pointer;
  outline: none;
}

.contact-lens-icon{
  width: 28px;
  height: 18px;
  vertical-align: -2px;
}

.contact-lens-lightmode-icon, .contact-lens-darkmode-icon{
  width: 42px;
  height: 32px;
  vertical-align: -3px;
}

/* -------- Lens Transposition UI Style -------- */

.lensTranspositionUIHeader, .lensTranspositionFormContainer, .conversionMenu{
  margin-top: 20px;
}

.effectivePowerFormContainer{
  margin-top: 30px;
}

.cyl-form-header{
  margin-top: 10px;
}

.promptPrescriptionForm{
  margin-top: 15px;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  gap: 1rem;
}

.plusCylPrescriptionForm, .minusCylPrescriptionForm, .crossCylPrescriptionForm, .sphericalPrescriptionEp, .cylindricalPrescriptionEp, .sphericalEquivalentPrescriptionContainer {
  margin-top: 10px;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  gap: 1rem;
}

.divisionArea p {
    position: relative;
    top: 15px;
}

.inputForm{
  display: flex;
  flex-direction: column;
  vertical-align: center;
  align-items: center;
}

.prescriptionInput{
  width: 85px;
}

.conversionArea{
  margin-top: 50px;
}

.conversionMenu{
  margin-top: 20px;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  gap: 1rem;
}

.lensTranspositionResultBox{
  margin-top: 50px;
  background: var(--light-bg);
  color: var(--black);
  border: 1px solid #ccc;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.05);
  height: 175px;
}

.lensTranspositionResultBox p{
  margin-top: 50px;
}

#lensTranspositionResetBtn{
  margin-top: 70px;
}

/* -------- EFFECTIVE POWER UI STYLE -------- */

.effectivePowerUIHeader{
  margin-top: 20px;
}

.effectivePowerBody{
  margin-top: 30px;
}

.effectivePowerResultBox{
  margin-top: 50px;
  background: var(--light-bg);
  color: var(--black);
  border: 1px solid #ccc;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.05);
  height: 175px;
}

.effectivePowerResultBox p{
  margin-top: 50px;
}

.vertexDistanceInput {
  margin-top: 15px;
}

#effectivePowerComputeBtn{
  margin-top: 30px;
}

#effectivePowerResetBtn{
  margin-top: 70px;
}

/* -------- Spherical Equivalent -------- */

.spherical-equivalent-form-header{
  margin-top: 20px;
}

.flatKinput{
  width: 100px;
}

.sphericalEquivalentResultBox{
  margin-top: 50px;
  background: var(--light-bg);
  color: var(--black);
  border: 1px solid #ccc;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.05);
  height: 175px;
}

.sphericalEquivalentResultBox p{
  margin-top: 50px;
}

.sphericalEquivalentComputeBtn{
  margin-top: 30px;
}

#sphericalEquivalentResetBtn{
  margin-top: 70px;
}

/* -------- Base Curve -------- */

.clTypeArea{
  margin-top: 50px;
}

.clTypeMenu{
  margin-top: 20px;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  gap: 1rem;
}

.baseCurveResultBox{
  margin-top: 50px;
  background: var(--light-bg);
  color: var(--black);
  border: 1px solid #ccc;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.05);
  height: 175px;
}

.baseCurveResultBox p{
  margin-top: 50px;
}

#baseCurveResetBtn{
  margin-top: 70px;
}

/* -------- Formula Section Style -------- */

.formulaSection {
  position: relative;
  padding-top: 3rem;
  margin-top: 3rem;
}

.formula-img {
  max-width: 600px;
  width: 100%;
  height: auto;
  margin: 1rem auto;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

#lensTranspositionFormulaBackBtn{
  margin-top: 70px;
}

#contactLensParameterFormulaBackBtn{
  margin-top: 70px;
}

/* -------- Guide Section Style -------- */

.guideMenu{
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.guideSection {
  position: relative;
  padding-top: 1.5rem;
  margin-top: 1.5rem;
}

#guideBackBtn{
  margin-top: 70px;
}

/* -------- Footer -------- */
.footer {
  background: var(--primary-color);
  color: var(--white);
  text-align: center;
  padding: 20px;
  margin-top: auto;
}

/* -------- Dark Mode Theme -------- */

.color-text.darkMode {
  color: #FFD700;  /* yellow */
}

/* -------- Style Functions -------- */

.hidden{
  display: none;
}

/* -------- Responsive Media -------- */
@media (max-width: 1100px) {
  .page-content {
    padding: 0 30px;
  }

  .page-content p {
    width: 90%;
  }
}

/* ------- Mobile Device ------- */
@media (max-width: 768px) {

  .appearance-area {
    display: flex;
    align-items: center;
    gap: 10px;
  }

  .conversionMenu, .clTypeMenu{
    flex-direction: column;
  }
  
}