:root {
    --primary-color: #0070f3;
    --primary-hover: #0051cc;
    --secondary-color: #ff3366;
    --accent-color: #7c3aed;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --text-primary: #1a1a1a;
    --text-secondary: #666;
    --text-muted: #999;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

/* Animated Background */
body::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
            radial-gradient(circle at 20% 50%, rgba(120, 119, 198, 0.3) 0%, transparent 50%),
            radial-gradient(circle at 80% 20%, rgba(255, 119, 198, 0.3) 0%, transparent 50%),
            radial-gradient(circle at 40% 80%, rgba(120, 219, 255, 0.3) 0%, transparent 50%);
    animation: backgroundShift 20s ease-in-out infinite;
}

@keyframes backgroundShift {
    0%, 100% { transform: translateX(0) translateY(0); }
    33% { transform: translateX(-30px) translateY(-30px); }
    66% { transform: translateX(30px) translateY(30px); }
}

/* Floating Particles */
.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    animation: float 6s ease-in-out infinite;
}

.particle:nth-child(1) { top: 10%; left: 15%; animation-delay: 0s; }
.particle:nth-child(2) { top: 70%; left: 25%; animation-delay: 2s; }
.particle:nth-child(3) { top: 50%; left: 85%; animation-delay: 4s; }
.particle:nth-child(4) { top: 30%; left: 70%; animation-delay: 1s; }
.particle:nth-child(5) { top: 80%; left: 10%; animation-delay: 3s; }
.particle:nth-child(6) { top: 20%; left: 60%; animation-delay: 5s; }

@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); opacity: 1; }
    50% { transform: translateY(-20px) rotate(180deg); opacity: 0.5; }
}

/* Signup Container */
.signup-section {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 2rem;
    position: relative;
    z-index: 10;
}

.signup-container {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-radius: var(--radius-xl);
    padding: 3rem;
    width: 100%;
    max-width: 600px;
    box-shadow: var(--shadow-xl);
    border: 1px solid rgba(255, 255, 255, 0.2);
    position: relative;
    overflow: hidden;
    max-height: 90vh;
    overflow-y: auto;
}

.signup-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color), var(--secondary-color));
    animation: gradientShift 3s ease-in-out infinite;
}

@keyframes gradientShift {
    0%, 100% { transform: translateX(-100%); }
    50% { transform: translateX(100%); }
}

/* Header */
.signup-header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.brand-logo {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.brand-logo:hover {
    transform: scale(1.05);
}

.signup-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.signup-subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Back Button */
.back-button {
    position: absolute;
    top: 2rem;
    left: 2rem;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    color: var(--text-primary);
    z-index: 100;
}

.back-button:hover {
    transform: translateY(-2px) scale(1.05);
    box-shadow: var(--shadow-lg);
    color: var(--primary-color);
}

/* Form Styles */
.signup-form {
    margin-bottom: 2rem;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group.full-width {
    grid-column: 1 / -1;
}

.form-label {
    display: block;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
}

.input-wrapper {
    position: relative;
}

.form-input {
    width: 100%;
    padding: 1rem 1rem 1rem 3rem;
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    font-size: 1rem;
    background: rgba(255, 255, 255, 0.8);
    transition: all 0.3s ease;
    outline: none;
}

.form-input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 112, 243, 0.1);
    background: rgba(255, 255, 255, 1);
}

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

.form-input.error {
    border-color: var(--error-color);
    animation: shake 0.5s ease-in-out;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

.input-icon {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-size: 1.1rem;
    transition: color 0.3s ease;
}

.form-input:focus + .input-icon {
    color: var(--primary-color);
}

/* Input Group */
.input-group {
    display: flex;
    gap: 0.5rem;
    align-items: stretch;
}

.input-group .form-input {
    flex: 1;
}

.check-button,
.toggle-button {
    padding: 0 1.5rem;
    background: rgba(255, 255, 255, 0.9);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.check-button:hover,
.toggle-button:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.check-button.checking {
    background: var(--warning-color);
    color: white;
    border-color: var(--warning-color);
}

.check-button.success {
    background: var(--success-color);
    color: white;
    border-color: var(--success-color);
}

.check-button.error {
    background: var(--error-color);
    color: white;
    border-color: var(--error-color);
}

/* Select Styles */
.form-select {
    width: 100%;
    padding: 1rem 1rem 1rem 3rem;
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    font-size: 1rem;
    background: rgba(255, 255, 255, 0.8);
    transition: all 0.3s ease;
    outline: none;
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
    background-position: right 1rem center;
    background-repeat: no-repeat;
    background-size: 1.5em 1.5em;
}

.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 112, 243, 0.1);
    background-color: rgba(255, 255, 255, 1);
}

/* Messages */
.form-message {
    font-size: 0.875rem;
    margin-top: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    opacity: 0;
    transform: translateY(-10px);
    transition: all 0.3s ease;
}

.form-message.show {
    opacity: 1;
    transform: translateY(0);
}

.form-message.success {
    color: var(--success-color);
}

.form-message.error {
    color: var(--error-color);
}

.form-message.warning {
    color: var(--warning-color);
}

/* Progress Indicator */
.password-strength {
    margin-top: 0.5rem;
}

.strength-bar {
    height: 4px;
    background: var(--border-light);
    border-radius: 2px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.strength-fill {
    height: 100%;
    transition: all 0.3s ease;
    border-radius: 2px;
}

.strength-text {
    font-size: 0.75rem;
    font-weight: 500;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
    position: relative;
    overflow: hidden;
    width: 100%;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    color: white;
    margin-bottom: 1rem;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-primary:disabled {
    background: var(--border-medium);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    border: 2px solid var(--border-light);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* Loading Animation */
.loading {
    display: none;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.spinner {
    width: 24px;
    height: 24px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top: 3px solid white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Success Checkmark Animation */
.success-checkmark {
    display: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--success-color);
    position: relative;
}

.success-checkmark::after {
    content: '';
    position: absolute;
    left: 8px;
    top: 4px;
    width: 6px;
    height: 12px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.success-checkmark.show {
    display: block;
    animation: checkmarkPop 0.3s ease;
}

@keyframes checkmarkPop {
    0% { transform: scale(0); }
    50% { transform: scale(1.2); }
    100% { transform: scale(1); }
}

/* Responsive Design */
@media (max-width: 768px) {
    .signup-section {
        padding: 1rem;
    }

    .signup-container {
        padding: 2rem 1.5rem;
        margin: 1rem;
        max-height: 95vh;
    }

    .brand-logo {
        font-size: 2rem;
    }

    .form-row {
        grid-template-columns: 1fr;
        gap: 0;
    }

    .back-button {
        top: 1rem;
        left: 1rem;
        width: 40px;
        height: 40px;
    }

    .input-group {
        flex-direction: column;
        gap: 0.75rem;
    }

    .check-button,
    .toggle-button {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .signup-container {
        padding: 1.5rem 1rem;
    }

    .form-input,
    .form-select {
        padding: 0.875rem 0.875rem 0.875rem 2.5rem;
    }
}

/* Custom Scrollbar */
.signup-container::-webkit-scrollbar {
    width: 6px;
}

.signup-container::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 3px;
}

.signup-container::-webkit-scrollbar-thumb {
    background: rgba(0, 112, 243, 0.3);
    border-radius: 3px;
}

.signup-container::-webkit-scrollbar-thumb:hover {
    background: rgba(0, 112, 243, 0.5);
}

/* Focus Styles for Accessibility */
.btn:focus-visible,
.check-button:focus-visible,
.toggle-button:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.form-input:focus-visible,
.form-select:focus-visible {
    outline: none;
}