:root {
  --primary: #6c63ff;
  --primary-dark: #554fd8;
  --secondary: #ff6584;
  --dark: #2a2a3c;
  --light: #f8f9fa;
  --gray: #e9ecef;
  --gray-dark: #adb5bd;
  --success: #4caf50;
  --border-radius: 12px;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
  --transition: all 0.3s ease;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

body {
  background-color: #f9f9ff;
  color: var(--dark);
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
header {
  background: linear-gradient(
    135deg,
    var(--primary) 0%,
    var(--primary-dark) 100%
  );
  color: white;
  padding: 80px 0 100px;
  text-align: center;
  border-radius: 0 0 40px 40px;
  position: relative;
  overflow: hidden;
}

header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23ffffff" fill-opacity="0.1" d="M0,224L48,213.3C96,203,192,181,288,181.3C384,181,480,203,576,202.7C672,203,768,181,864,181.3C960,181,1056,203,1152,213.3C1248,224,1344,224,1392,224L1440,224L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>');
  background-size: cover;
  background-position: center;
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 20px;
}

.logo-icon {
  background-color: white;
  color: var(--primary);
  width: 50px;
  height: 50px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.tagline {
  font-size: 18px;
  max-width: 700px;
  margin: 0 auto 40px;
  opacity: 0.9;
}

/* Main Features */
.features {
  display: flex;
  justify-content: center;
  gap: 30px;
  flex-wrap: wrap;
  position: relative;
  z-index: 2;
}

.feature-card {
  background-color: white;
  border-radius: var(--border-radius);
  padding: 30px;
  width: 280px;
  box-shadow: var(--shadow);
  text-align: center;
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.12);
}

.feature-icon {
  background-color: rgba(108, 99, 255, 0.1);
  color: var(--primary);
  width: 70px;
  height: 70px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  font-size: 28px;
}

.feature-title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 15px;
  color: var(--dark);
}

.feature-desc {
  color: var(--gray-dark);
  font-size: 15px;
}

/* Converter Section */
.converter-section {
  padding: 100px 0;
}

.section-title {
  text-align: center;
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 15px;
}

.section-subtitle {
  text-align: center;
  color: var(--gray-dark);
  font-size: 18px;
  max-width: 700px;
  margin: 0 auto 60px;
}

.converter-box {
  background-color: white;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  padding: 40px;
  max-width: 900px;
  margin: 0 auto;
}

.tabs {
  display: flex;
  border-bottom: 2px solid var(--gray);
  margin-bottom: 30px;
}

.tab {
  padding: 15px 30px;
  font-size: 17px;
  font-weight: 600;
  color: var(--gray-dark);
  cursor: pointer;
  transition: var(--transition);
  border-bottom: 3px solid transparent;
  margin-bottom: -2px;
}

.tab.active {
  color: var(--primary);
  border-bottom: 3px solid var(--primary);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

.upload-area {
  border: 3px dashed var(--gray);
  border-radius: var(--border-radius);
  padding: 60px 20px;
  text-align: center;
  margin-bottom: 40px;
  transition: var(--transition);
  cursor: pointer;
  position: relative;
}

.upload-area:hover {
  border-color: var(--primary);
}

.upload-icon {
  font-size: 60px;
  color: var(--primary);
  margin-bottom: 20px;
}

.upload-text {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 10px;
}

.upload-subtext {
  color: var(--gray-dark);
  margin-bottom: 20px;
}

.btn {
  background-color: var(--primary);
  color: white;
  border: none;
  padding: 15px 30px;
  border-radius: 50px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.btn:hover {
  background-color: var(--primary-dark);
  transform: translateY(-2px);
}

.btn-secondary {
  background-color: var(--secondary);
}

.btn-secondary:hover {
  background-color: #ff5073;
}

.options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 25px;
  margin-top: 30px;
}

.option-group {
  margin-bottom: 20px;
}

.option-label {
  display: block;
  font-weight: 600;
  margin-bottom: 10px;
  font-size: 16px;
}

.select-wrapper,
.input-wrapper {
  position: relative;
}

select,
input {
  width: 100%;
  padding: 15px 20px;
  border: 2px solid var(--gray);
  border-radius: var(--border-radius);
  font-size: 16px;
  background-color: white;
  appearance: none;
  transition: var(--transition);
}

select:focus,
input:focus {
  outline: none;
  border-color: var(--primary);
}

.select-wrapper::after {
  content: "\f078";
  font-family: "Font Awesome 6 Free";
  font-weight: 900;
  position: absolute;
  right: 20px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--primary);
  pointer-events: none;
}

.range-value {
  display: block;
  text-align: center;
  font-weight: 600;
  margin-top: 10px;
  color: var(--primary);
}

.action-buttons {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-top: 40px;
}

/* How it works */
.how-it-works {
  background-color: var(--dark);
  color: white;
  padding: 80px 0;
  border-radius: 40px 40px 0 0;
}

.steps {
  display: flex;
  justify-content: center;
  gap: 40px;
  flex-wrap: wrap;
  margin-top: 50px;
}

.step {
  text-align: center;
  max-width: 250px;
}

.step-number {
  background-color: var(--primary);
  color: white;
  width: 60px;
  height: 60px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  font-weight: 700;
  margin: 0 auto 25px;
}

.step-title {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 15px;
}

/* Footer */
footer {
  background-color: var(--dark);
  color: var(--gray);
  padding: 40px 0;
  text-align: center;
}

.copyright {
  margin-top: 20px;
  font-size: 14px;
}

/* Responsive */
@media (max-width: 768px) {
  .feature-card {
    width: 100%;
    max-width: 350px;
  }

  .tabs {
    flex-direction: column;
  }

  .tab {
    text-align: center;
  }

  .action-buttons {
    flex-direction: column;
  }

  .btn {
    justify-content: center;
  }
}

/* Дополнительные стили для работы */
.file-info {
  background: #f8f9fa;
  padding: 15px;
  border-radius: var(--border-radius);
  margin-bottom: 20px;
  display: none;
}

.file-name {
  font-weight: 600;
  color: var(--primary);
}

.file-size {
  color: var(--gray-dark);
  margin-left: 10px;
}

.processing-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  display: none;
}

.processing-content {
  background: white;
  padding: 40px;
  border-radius: var(--border-radius);
  text-align: center;
  max-width: 400px;
  width: 90%;
}