:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --bg-color: #f3f4f6;
    --card-bg: #ffffff;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --border-color: #d1d5db;
    --border-focus: #4f46e5;
    --error-color: #ef4444;
    --success-color: #10b981;
    --radius-sm: 6px;
    --radius-md: 12px;
    --shadow-md: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
    --transition: all 0.2s ease-in-out;
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.registration-container {
    width: 100%;
    max-width: 440px;
}

.card {
    background-color: var(--card-bg);
    padding: 2.5rem 2rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
}

.card-header {
    text-align: center;
    margin-bottom: 2rem;
}

.card-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.card-header p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.registration-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.375rem;
}

.form-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-wrapper input {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 0.95rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    outline: none;
    transition: var(--transition);
    background-color: #fafafa;
}

.input-wrapper input:focus {
    border-color: var(--border-focus);
    background-color: #ffffff;
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
}

.input-wrapper input.invalid {
    border-color: var(--error-color);
    background-color: #fef2f2;
}

.toggle-password {
    position: absolute;
    right: 0.75rem;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.25rem;
}

.toggle-password:hover {
    color: var(--text-primary);
}

.error-message {
    font-size: 0.75rem;
    color: var(--error-color);
    min-height: 1rem;
}

/* Custom Checkbox */
.checkbox-group {
    margin-top: 0.25rem;
}

.checkbox-container {
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
    cursor: pointer;
    user-select: none;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.checkbox-container a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.checkbox-container a:hover {
    text-decoration: underline;
}

.checkbox-container input {
    margin-top: 0.15rem;
    accent-color: var(--primary-color);
    width: 16px;
    height: 16px;
    cursor: pointer;
}

/* Submit Button */
.submit-btn {
    width: 100%;
    padding: 0.85rem;
    font-size: 1rem;
    font-weight: 600;
    color: #ffffff;
    background-color: var(--primary-color);
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    margin-top: 0.5rem;
}

.submit-btn:hover {
    background-color: var(--primary-hover);
}

.submit-btn:active {
    transform: scale(0.98);
}

/* Sign In Link */
.signin-link {
    text-align: center;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

.signin-link a {
    color: var(--primary-color);
    font-weight: 600;
    text-decoration: none;
}

.signin-link a:hover {
    text-decoration: underline;
}

@media (max-width: 480px) {
    .card {
        padding: 1.75rem 1.25rem;
    }
}