:root {
  /* Paleta principal */
  --primary-color: #233045;
  --primary-gradient: linear-gradient(90deg, #233045 60%, #1abc9c 100%);
  --accent-color: #16a085;
  --accent-gradient: linear-gradient(90deg, #16a085 60%, #2ecc71 100%);
  --secondary-color: #f4f8fb;
  --surface-glass: rgba(255, 255, 255, 0.72);
  --light-bg: #ffffff;
  --text-color: #2d3c4e;
  --text-light: #7b8ca0;
  --error-color: #e74c3c;
  --border-radius: 16px;
  --border-radius-sm: 8px;
  --box-shadow: 0 4px 32px 0 rgba(44, 62, 80, 0.08),
    0 1.5px 6px rgba(44, 62, 80, 0.04);
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: "Inter", "Roboto", Arial, sans-serif;
  background: var(--primary-gradient);
  color: var(--text-color);
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

header {
  background: var(--primary-gradient);
  color: var(--light-bg);
  padding: 2.2rem 0 1.2rem 0;
  width: 100%;
  text-align: center;
  box-shadow: 0 3px 18px rgba(35, 48, 69, 0.08);
}

header h1 {
  font-weight: 800;
  font-size: 2.5rem;
  letter-spacing: -0.5px;
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.1);
}

main {
  flex: 1 0 auto;
  width: 100%;
  display: flex;
  justify-content: center;
  padding: 32px 0;
}

.app-container {
  background: var(--surface-glass);
  backdrop-filter: blur(8px);
  box-shadow: var(--box-shadow);
  border-radius: var(--border-radius);
  padding: 36px 40px;
  width: 100%;
  max-width: 540px;
  margin: 20px 0;
  border: 1.5px solid rgba(44, 62, 80, 0.04);
  transition: box-shadow var(--transition);
  animation: fadein 0.7s;
}
@keyframes fadein {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.input-section label {
  display: block;
  margin-bottom: 10px;
  color: var(--primary-color);
  font-weight: 600;
  letter-spacing: 0.04em;
}

.input-section input[type="text"],
.input-section select {
  width: 100%;
  padding: 15px 12px;
  margin-bottom: 20px;
  border: 1.2px solid #e0e6ed;
  border-radius: var(--border-radius-sm);
  font-size: 1.08rem;
  background: rgba(244, 248, 251, 0.85);
  transition: border-color var(--transition), box-shadow var(--transition);
  outline: none;
}
.input-section input[type="text"]:focus,
.input-section select:focus {
  border-color: var(--accent-color);
  box-shadow: 0 0 0 2px rgba(22, 160, 133, 0.08);
}

#generateButton,
#downloadButton {
  width: 100%;
  padding: 15px 0;
  background: var(--accent-gradient);
  color: #fff;
  border: none;
  border-radius: var(--border-radius-sm);
  font-size: 1.12rem;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 1.5px 7px rgba(22, 160, 133, 0.07);
  margin-bottom: 10px;
  letter-spacing: 0.02em;
  transition: background var(--transition), transform 0.13s;
  will-change: transform;
  outline: none;
}
#generateButton:hover,
#downloadButton:hover {
  background: linear-gradient(90deg, #1abc9c 70%, #16a085 100%);
  transform: translateY(-1.5px) scale(1.015);
}
#generateButton:active,
#downloadButton:active {
  transform: scale(0.98);
}
#downloadButton {
  margin-top: 0;
  background: linear-gradient(90deg, #16a085 60%, #2ecc71 100%);
}

.error-message {
  background: rgba(231, 76, 60, 0.1);
  color: var(--error-color);
  padding: 12px 18px;
  margin: 18px 0;
  border-radius: var(--border-radius-sm);
  border-left: 5px solid var(--error-color);
  font-size: 1rem;
  display: none;
}

.output-section {
  margin-top: 36px;
  text-align: center;
}

.output-section h2 {
  margin-bottom: 16px;
  color: var(--primary-color);
  font-weight: 500;
  letter-spacing: 0.01em;
}

#outputContainer {
  background: #f9fafb;
  border: 1.2px dashed #d0d7de;
  border-radius: var(--border-radius-sm);
  padding: 28px;
  min-height: 144px;
  display: flex;
  justify-content: center;
  align-items: center;
  margin-bottom: 22px;
  overflow: auto;
}

#outputContainer img,
#outputContainer svg,
#outputContainer canvas {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 0 auto;
  filter: drop-shadow(0 1.5px 4px rgba(44, 62, 80, 0.1));
}

footer {
  text-align: center;
  padding: 20px 0;
  background: rgba(233, 236, 239, 0.97);
  color: #7b8ca0;
  font-size: 1rem;
  width: 100%;
  margin-top: auto;
  border-top: 1px solid #e0e6ed;
  letter-spacing: 0.02em;
}

/* Responsive adjustments */
@media (max-width: 900px) {
  .app-container {
    padding: 26px 8vw;
  }
}
@media (max-width: 600px) {
  header h1 {
    font-size: 1.5rem;
  }
  .app-container {
    padding: 18px 4vw;
  }
  .output-section {
    margin-top: 20px;
  }
  #outputContainer {
    padding: 14px;
    min-height: 70px;
  }
}