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

:root {
    --primary-color: #667eea;
    --primary-dark: #5568d3;
    --secondary-color: #764ba2;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    color: var(--text-primary);
}

.container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    max-width: 1200px;
    width: 100%;
    background: var(--bg-primary);
    border-radius: 24px;
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Auth Box */
.auth-box {
    padding: 60px 50px;
    display: flex;
    flex-direction: column;
}

.auth-header {
    text-align: center;
    margin-bottom: 40px;
}

.logo {
    display: inline-flex;
    margin-bottom: 20px;
    animation: rotate 20s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.auth-header h1 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.auth-header p {
    color: var(--text-secondary);
    font-size: 15px;
}

/* Alerts */
.alert {
    padding: 14px 16px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 24px;
    font-size: 14px;
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.alert-error {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.alert-success {
    background: #d1fae5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.alert svg {
    flex-shrink: 0;
}

/* Form */
.auth-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
}

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

.input-icon {
    position: absolute;
    right: 16px;
    color: var(--text-secondary);
    pointer-events: none;
}

.input-group input {
    width: 100%;
    padding: 14px 48px 14px 16px;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    font-size: 15px;
    transition: all 0.3s ease;
    background: var(--bg-secondary);
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    background: var(--bg-primary);
    box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.1);
}

.input-group input::placeholder {
    color: #9ca3af;
}

.password-toggle {
    position: absolute;
    left: 16px;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px;
    display: flex;
    align-items: center;
    transition: color 0.2s ease;
}

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

.form-hint {
    font-size: 13px;
    color: var(--text-secondary);
    margin-top: -4px;
}

/* Password Strength */
.password-strength {
    display: flex;
    flex-direction: column;
    gap: 6px;
    margin-top: -4px;
}

.strength-bar {
    height: 4px;
    background: var(--border-color);
    border-radius: 2px;
    position: relative;
    overflow: hidden;
}

.strength-bar::after {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    height: 100%;
    width: 0%;
    background: var(--error-color);
    transition: all 0.3s ease;
}

.strength-bar.weak::after {
    width: 33%;
    background: var(--error-color);
}

.strength-bar.medium::after {
    width: 66%;
    background: var(--warning-color);
}

.strength-bar.strong::after {
    width: 100%;
    background: var(--success-color);
}

.strength-text {
    font-size: 12px;
    color: var(--text-secondary);
}

/* Form Options */
.form-options {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 14px;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    user-select: none;
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--primary-color);
}

.link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

.link:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

/* Buttons */
.btn {
    padding: 14px 24px;
    border: none;
    border-radius: 12px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:active::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 20px -10px rgba(102, 126, 234, 0.5);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-block {
    width: 100%;
}

.btn svg {
    transition: transform 0.3s ease;
}

.btn:hover svg {
    transform: translateX(-4px);
}

/* Auth Footer */
.auth-footer {
    margin-top: 32px;
    text-align: center;
    font-size: 14px;
    color: var(--text-secondary);
}

.link-primary {
    color: var(--primary-color);
    font-weight: 600;
    text-decoration: none;
    transition: color 0.2s ease;
}

.link-primary:hover {
    color: var(--primary-dark);
}

/* Illustration Section */
.auth-illustration {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 60px 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    position: relative;
    overflow: hidden;
}

.auth-illustration::before {
    content: '';
    position: absolute;
    width: 300px;
    height: 300px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    top: -100px;
    left: -100px;
    animation: float 20s infinite ease-in-out;
}

.auth-illustration::after {
    content: '';
    position: absolute;
    width: 200px;
    height: 200px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    bottom: -50px;
    right: -50px;
    animation: float 15s infinite ease-in-out reverse;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0); }
    50% { transform: translate(30px, 30px); }
}

.illustration-content {
    position: relative;
    z-index: 1;
}

.illustration-content h2 {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 16px;
    line-height: 1.2;
}

.illustration-content > p {
    font-size: 18px;
    opacity: 0.9;
    margin-bottom: 40px;
    line-height: 1.6;
}

/* Features */
.features {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.feature {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    transition: all 0.3s ease;
}

.feature:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateX(-8px);
}

.feature svg {
    flex-shrink: 0;
}

.feature span {
    font-size: 16px;
    font-weight: 500;
}

/* Stats */
.stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 40px;
}

.stat {
    text-align: center;
    padding: 24px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    transition: all 0.3s ease;
}

.stat:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-4px);
}

.stat h3 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 8px;
}

.stat p {
    font-size: 14px;
    opacity: 0.9;
}

/* Responsive Design */
@media (max-width: 968px) {
    .container {
        grid-template-columns: 1fr;
    }
    
    .auth-illustration {
        display: none;
    }
    
    .auth-box {
        padding: 40px 30px;
    }
}

@media (max-width: 640px) {
    .auth-box {
        padding: 30px 20px;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .auth-header h1 {
        font-size: 24px;
    }
    
    .form-options {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }
}

/* Loading State */
.btn.loading {
    pointer-events: none;
    opacity: 0.7;
}

.btn.loading::after {
    content: '';
    position: absolute;
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Input validation states */
.input-group input.invalid {
    border-color: var(--error-color);
}

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

.input-group input.invalid:focus {
    box-shadow: 0 0 0 4px rgba(239, 68, 68, 0.1);
}

.input-group input.valid:focus {
    box-shadow: 0 0 0 4px rgba(16, 185, 129, 0.1);
}

/* Smooth transitions */
* {
    transition: background-color 0.2s ease;
}