@charset "utf-8";
:root {
  --bg: #111218;
  --bg-elevated: #1a1b23;
  --card: #1e1f28;
  --card-hover: #24252e;
  --text-primary: #e0e2f0;
  --text-secondary: #b8bcc8;
  --text-muted: #a4abb8;
  --accent: #6366f1;
  --accent-hover: #7c3aed;
  --accent-soft: rgba(99, 102, 241, 0.12);
  --border: rgba(255, 255, 255, 0.08);
  --border-focus: rgba(99, 102, 241, 0.4);
  --success: #10b981;
  --warning: #f59e0b;
  --error: #ef4444;
  --radius: 12px;
  --radius-lg: 16px;
  --transition: all 0.2s ease;
  --fs-md: 16px;
  --fs-lg: 18px;
  --fs-xl: 22px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text-primary);
  font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN",
    "Hiragino Sans", Meiryo, sans-serif;
  line-height: 1.7;
  font-size: 15px;
}

main {
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 20px;
}

.box {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 40px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

/* Progress Steps */
.progress {
  display: flex;
  justify-content: space-between;
  list-style: none;
  margin: 0 0 40px;
  padding: 0;
  counter-reset: step;
  position: relative;
}

.progress::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--border);
  transform: translateY(-50%);
  z-index: 1;
}

.progress li {
  position: relative;
  flex: 1;
  text-align: center;
  counter-increment: step;
  z-index: 2;
}

.progress li::before {
  content: counter(step);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--card);
  border: 2px solid var(--border);
  color: var(--text-muted);
  font-weight: 600;
  font-size: 14px;
  margin-bottom: 8px;
}

.progress li.step {
  color: var(--accent);
}

.progress li.step::before {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.progress li {
  color: var(--text-muted);
  font-size: 14px;
  font-weight: 500;
}

/* Form Styles */
form {
  display: grid;
  gap: 24px;
}

form > div {
  display: grid;
  gap: 8px;
}

label {
  color: var(--text-primary);
  font-weight: 600;
  font-size: var(--fs-md);
}

input[type="text"],
input[type="email"],
textarea {
  width: 100%;
  padding: 16px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--text-primary);
  font-size: var(--fs-md);
  font-family: inherit;
  transition: var(--transition);
  resize: vertical;
}

input[type="text"]:focus,
input[type="email"]:focus,
textarea:focus {
  outline: none;
  border-color: var(--border-focus);
  background: var(--bg-elevated);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

textarea {
  min-height: 120px;
  line-height: 1.6;
}

/* Submit Button */
input[type="submit"] {
  background: linear-gradient(
    135deg,
    var(--accent) 0%,
    var(--accent-hover) 100%
  );
  color: white;
  border: none;
  border-radius: var(--radius);
  padding: 16px 32px;
  font-size: var(--fs-lg);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 16px rgba(99, 102, 241, 0.3);
}

input[type="submit"]:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(99, 102, 241, 0.4);
}

input[type="submit"]:active {
  transform: translateY(0);
}

/* Form validation styles */
/* input:invalid {
  border-color: var(--error);
} */

input:valid {
  border-color: var(--success);
}

/* Error message styling */
.error-message {
  color: var(--error);
  font-size: 14px;
  margin-top: 4px;
  display: none;
}

/* Responsive */
@media (max-width: 768px) {
  main {
    padding: 20px 12px;
  }

  .box {
    padding: 24px;
  }

  .progress {
    flex-direction: column;
    gap: 12px;
    margin-bottom: 32px;
  }

  .progress::before {
    display: none;
  }

  .progress li {
    display: flex;
    align-items: center;
    gap: 12px;
    text-align: left;
  }

  .progress li::before {
    margin-bottom: 0;
  }

  input[type="text"],
  input[type="email"],
  textarea {
    padding: 12px 16px;
  }

  input[type="submit"] {
    padding: 14px 24px;
    font-size: var(--fs-md);
  }
}

@media (max-width: 480px) {
  .box {
    padding: 20px;
  }
}

/* Animation for form elements */
form > div {
  opacity: 0;
  transform: translateY(20px);
  animation: slideUp 0.6s ease forwards;
}

form > div:nth-child(1) {
  animation-delay: 0.1s;
}
form > div:nth-child(2) {
  animation-delay: 0.2s;
}
form > div:nth-child(3) {
  animation-delay: 0.3s;
}
form > div:nth-child(4) {
  animation-delay: 0.4s;
}

@keyframes slideUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Header styling */
.form-header {
  text-align: center;
  margin-bottom: 40px;
}

.form-header h1 {
  color: var(--text-primary);
  font-size: var(--fs-xl);
  margin: 0 0 16px;
  font-weight: 700;
}

.form-header p {
  color: var(--text-secondary);
  margin: 0;
  font-size: var(--fs-md);
}