/* ==================== 1. Base & Reset ==================== */
html {
  height: 100%;
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  margin: 0;
  font-family: 'Poppins', sans-serif;
  display: flex;
  flex-direction: column;
  background: #fff;
  color: #333;
  transition: background 0.4s ease, color 0.4s ease;
}

body.dark {
  background: #1a1a1a;
  color: #fff;
}

/* ==================== 2. Navbar  ==================== */
.nav-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: flex;
  align-items: center;
  padding: 0 40px;
  z-index: 1000;
  flex: 1;
  transition: all 0.3s ease;
  box-sizing: border-box;
}

body.light .nav-container { 
  background: #ffffff;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
  border-bottom: 1px solid #eaeaea;
}

body.dark .nav-container { 
  background: #222222;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  border-bottom: 1px solid #333333;
}

.logo {
  height: 60px;
  width: auto;
  object-fit: contain;
  margin-right: 40px;
  flex-shrink: 0;
  max-width: 120px;
}

/* Navigation Links - Left aligned after logo */
.nav-links {
  display: flex;
  align-items: center;
  gap: 40px;
  margin-right: auto;
}

.nav-links a {
  text-decoration: none;
  font-size: 18px;
  font-weight: 500;
  color: #4a5568;
  padding: 8px 0;
  position: relative;
  transition: color 0.3s ease;
  white-space: nowrap;
}

body.dark .nav-links a {
  color: #cbd5e0;
}

.nav-links a:hover {
  color: #2652c0;
}

body.dark .nav-links a:hover {
  color: #a3bffa;
}

/* Simple underline effect */
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 3px;
  background: #2652c0;
  border-radius: 2px;
  transition: width 0.3s ease;
}

.nav-links a:hover::after {
  width: 100%;
}

/* Auth Buttons - Right aligned */
.auth-buttons {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-left: auto;
}

.auth-buttons button {
  padding: 10px 24px;
  border-radius: 6px;
  font-weight: 600;
  font-size: 16px;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
  white-space: nowrap;
}

#login-btn {
  background: transparent;
  color: #2652c0;
  border: 2px solid #2652c0;
}

body.dark #login-btn {
  color: #a3bffa;
  border-color: #a3bffa;
}

#login-btn:hover {
  background: rgba(38, 82, 192, 0.1);
  transform: translateY(-2px);
}

#register-btn {
  background: linear-gradient(135deg, #2652c0, #1ee9c0);
  color: white;
  box-shadow: 0 4px 12px rgba(38, 82, 192, 0.3);
}

#register-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(38, 82, 192, 0.4);
}

/* Theme Toggle Switch */
.switch {
  font-size: 17px;
  position: relative;
  display: inline-block;
  width: 3.5em;
  height: 2em;
  margin-left: 15px;
}

.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider {
  --background: #2652c0;
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--background);
  transition: .5s;
  border-radius: 30px;
}

.slider:before {
  position: absolute;
  content: "";
  height: 1.4em;
  width: 1.4em;
  border-radius: 50%;
  left: 10%;
  bottom: 15%;
  box-shadow: inset 8px -4px 0px 0px #fff000;
  background: var(--background);
  transition: .5s;
}

input:checked + .slider {
  background-color: #764ba2;
}

input:checked + .slider:before {
  transform: translateX(100%);
  box-shadow: inset 15px -4px 0px 15px #fff000;
}

/* Hamburger Menu - Hidden on desktop */
.hamburger {
  display: none;
  width: 35px;
  height: 30px;

  flex-direction: column;
  justify-content: space-between;

  background: none;
  border: none;
  cursor: pointer;

  margin-left: auto; 

  z-index: 1001;
}

.hamburger span {
  display: flex;
  height: 4px;
  width: 100%;
  justify-content: space-between;
  background-color: #2652c0;
  border-radius: 2px;
  transition: all 0.3s ease;
}

body.dark .hamburger span {
  background-color: #a3bffa;
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(8px, 8px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
  transform: translateX(20px);
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(7px, -7px);
}

/* Mobile Menu */
.mobile-menu {
  position: fixed;
  top: 0;
  right: -100%;
  width: 300px;
  height: 100vh;
  background: #ffffff;
  box-shadow: -5px 0 15px rgba(0, 0, 0, 0.1);
  z-index: 999;
  transition: right 0.4s ease;
  padding: 100px 30px;
  display: flex;
  flex-direction: column;
  gap: 30px;
}

body.dark .mobile-menu {
  background: #222222;
  box-shadow: -5px 0 15px rgba(0, 0, 0, 0.3);
}

.mobile-menu.active {
  right: 0;
}

.mobile-menu-links {
  display: flex;
  flex-direction: column;
  gap: 25px;
}

.mobile-menu-links a {
  font-size: 20px;
  font-weight: 500;
  color: #4a5568;
  text-decoration: none;
  padding: 12px 0;
  border-bottom: 1px solid #eaeaea;
  transition: color 0.3s ease;
}

body.dark .mobile-menu-links a {
  color: #cbd5e0;
  border-bottom-color: #333333;
}

.mobile-menu-links a:hover {
  color: #667eea;
}

.mobile-auth-buttons {
  display: flex;
  flex-direction: column;
  gap: 15px;
  margin-top: 20px;
}

.mobile-auth-buttons button {
  padding: 14px;
  border-radius: 6px;
  font-weight: 600;
  font-size: 17px;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
}

#mobile-login-btn {
  background: transparent;
  color: #667eea;
  border: 2px solid #667eea;
}

#mobile-register-btn {
  background: linear-gradient(135deg, #2652c0, #1ee9c0);
  color: white;
}

/* ==================== 3. Main Content ==================== */
main {
  flex: 1; /* take remaining space */
  display: flex;
  justify-content: center; /* horizontal centering */
  align-items: center;     /* vertical centering */
  padding: 100px 20px 40px 20px; /* top padding for fixed navbar */
  min-height: calc(100vh - 70px); /* full viewport minus navbar */
  box-sizing: border-box;
}

.form-container {
  width: 100%;
  max-width: 480px;        /* limits form width */
  padding: 40px 30px;
  margin: 0 auto;          /* horizontal center */
  background: #fff;
  border-radius: 28px;
  box-shadow: 0 25px 60px rgba(0,0,0,0.18);
}

body.dark .form-container {
  background: #2a2a2a;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
}

.title{
  align-items: center;
  justify-content: center;
  display: flex;
  text-align: center;
}

.form-container input {
  width: 90%;
  padding: 12px 15px;
  border-radius: 10px;
  border: 2px solid #e0e0e0;
  margin-bottom: 15px;
}

body.dark .form-container input {
  background: #333;
  color: #fff;
  border-color: #555;
}

.submit-btn {
  width: 100%;
  padding: 14px;
  align-items: center;
  background: linear-gradient(135deg, #2652c0, #1ee9c0);
  border: none;
  color: #fff;
  font-weight: 700;
  cursor: pointer;
  border-radius: 10px;
  transition: 0.3s;
}

.submit-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 15px rgba(102, 126, 234, 0.4);
}

/* ==================== 4. Footer ==================== */
footer {
  text-align: center;
  padding: 30px 20px;
  background: linear-gradient(135deg, #2652c0, #1ee9c0);
  color: #fff;
  font-weight: 500;
}

/* ==================== 5. Responsive ==================== */
@media (max-width: 768px) {
  .nav-links, .auth-buttons { display: none; }
  .hamburger { display: flex; }
  .logo { height: 50px; }
}

@media (max-width: 640px) {
  main {
    padding: 100px 15px 40px 15px;
  }
  .form-container {
    padding: 30px 20px;
  }
}

@media (max-width: 480px) {
  h1 { font-size: 1.8rem; }
  .form-container {
    padding: 25px 15px;
  }
  .form-container input {
    padding: 10px;
  }
  .submit-btn {
    padding: 12px;
  }
}