html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  box-sizing: border-box;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  font-family: "Montserrat", sans-serif;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: stretch;
}

header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  box-shadow: 0 2px 15px rgba(102, 126, 234, 0.3);
  width: 100%;
  margin-bottom: 30px;
}

header h2 {
  margin: 0 20px;
  padding: 25px 20px 22px 20px;
  text-align: center;
  color: #ffffff;
  font-size: 1.4em;
  font-weight: 600;
  text-shadow: 0 2px 4px rgba(0,0,0,0.1);
  background: rgba(255,255,255,0.1);
  border-radius: 15px;
  backdrop-filter: blur(10px);
}

main {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 0 20px 32px 20px;
  width: 100%;
  box-sizing: border-box;
}

.participant-form {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  padding: 30px;
  border-radius: 20px;
  box-shadow: 0 15px 35px rgba(0,0,0,0.1);
  max-width: 500px;
  width: calc(100% - 20px);
  margin: 0 auto 30px auto;
  box-sizing: border-box;
  border: 1px solid rgba(255,255,255,0.3);
}

.form-title {
  font-size: 1.2em;
  font-weight: 600;
  color: #2d3748;
  margin-bottom: 20px;
  text-align: center;
  border-bottom: 2px solid #667eea;
  padding-bottom: 10px;
}

label {
  display: block;
  margin-bottom: 8px;
  color: #2d3748;
  font-size: 0.95em;
  font-weight: 500;
}

input, select {
  width: 85%;
  margin: 0 auto 18px auto;
  display: block;
  padding: 14px 16px;
  border: 2px solid #e2e8f0;
  border-radius: 12px;
  font-size: 1em;
  background: #ffffff;
  box-sizing: border-box;
  transition: all .3s ease;
  font-family: "Montserrat", sans-serif;
  font-weight: 400;
}

input:focus, select:focus {
  outline: none;
  border-color: #667eea;
  background: #ffffff;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
  transform: translateY(-2px);
}

input:valid, select:valid {
  border-color: #48bb78;
}

input:invalid:not(:focus):not(:placeholder-shown) {
  border-color: #f56565;
}

input[type="tel"] {
  letter-spacing: 1px;
}

input:disabled, select:disabled {
  background-color: #f8f9fa;
  color: #6c757d;
  cursor: not-allowed;
}

.submit-button {
  width: 85%;
  max-width: 500px;
  margin: 20px auto 0 auto;
  display: block;
  padding: 16px 0;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: #fff;
  border: none;
  border-radius: 12px;
  font-size: 1.1em;
  font-weight: 600;
  cursor: pointer;
  transition: all .3s ease;
  font-family: "Montserrat", sans-serif;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.submit-button:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 25px rgba(102, 126, 234, 0.4);
}

.submit-button:active {
  transform: translateY(-1px);
}

.submit-button:disabled {
  background: #6b7280;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.error {
  color: #f56565;
  font-size: 0.9em;
  margin-bottom: 12px;
  min-height: 20px;
  font-weight: 500;
  background: rgba(245, 101, 101, 0.1);
  padding: 8px 12px;
  border-radius: 8px;
  border-left: 4px solid #f56565;
  text-align: center;
  max-width: 500px;
  width: calc(100% - 20px);
}

.success {
  color: #10b981;
  font-size: 0.9em;
  margin-top: 12px;
  font-weight: 500;
  background: rgba(16, 185, 129, 0.1);
  padding: 8px 12px;
  border-radius: 8px;
  border-left: 4px solid #10b981;
  text-align: center;
  max-width: 500px;
  width: calc(100% - 20px);
}

@media (max-width: 768px) {
  main { 
    padding: 0 15px 25px 15px; 
  }
  .participant-form {
    padding: 25px 20px;
    width: calc(100% - 10px);
  }
  header h2 {
    font-size: 1.2em;
    margin: 0 15px;
    padding: 20px 15px;
  }
}

@media (max-width: 480px) {
  main { 
    padding: 0 10px 20px 10px; 
  }
  .participant-form {
    width: calc(100% - 10px);
    padding: 20px 15px;
    margin-bottom: 20px;
  }
  input, select {
    width: 90%;
    font-size: 16px;
  }
  .submit-button {
    width: 90%;
    font-size: 1em;
    padding: 14px 0;
  }
  .form-title {
    font-size: 1.1em;
  }
}

.checkbox-group {
  margin: 20px auto;
  max-width: 460px;
  width: calc(100% - 40px);
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  padding: 20px;
  border-radius: 15px;
  box-shadow: 0 8px 25px rgba(0,0,0,0.1);
  border: 1px solid rgba(255,255,255,0.3);
  box-sizing: border-box;
}

.checkbox-label {
  display: flex;
  align-items: flex-start;
  cursor: pointer;
  font-size: 14px;
  line-height: 1.4;
  gap: 10px;
  color: #2d3748;
}

.checkbox-label input[type="checkbox"] {
  width: auto;
  margin: 0;
  flex-shrink: 0;
  margin-top: 2px;
}

.checkbox-text {
  flex: 1;
  word-wrap: break-word;
  white-space: normal;
}

.checkbox-label a {
  color: #667eea;
  text-decoration: underline;
}

.checkbox-label a:hover {
  color: #5a67d8;
}

.required-star {
  color: #f56565;
  font-weight: bold;
  margin-right: 5px;
}

.agreement-message {
  background: rgba(255, 255, 255, 0.95);
  color: #f56565;
  padding: 15px;
  margin: 20px auto;
  max-width: 460px;
  width: calc(100% - 40px);
  text-align: center;
  border-radius: 15px;
  border: 1px solid rgba(245, 101, 101, 0.3);
  font-weight: 500;
  box-sizing: border-box;
  backdrop-filter: blur(10px);
  box-shadow: 0 8px 25px rgba(0,0,0,0.1);
}

@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}