:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #f59e0b;
    --success-color: #10b981;
    --error-color: #ef4444;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --border-color: #e5e7eb;
    --shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 40px rgba(0, 0, 0, 0.15);
    --border-radius: 12px;
    --transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: clamp(10px, 3vw, 20px);
    line-height: 1.6;
}

.background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    z-index: -1;
}

/* Container Principal Responsivo */
.auth-container {
    width: 100%;
    max-width: min(400px, 95vw);
    position: relative;
    height: auto;
    min-height: 500px;
}

/* Sistema de Transição */
.auth-form {
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    transition: var(--transition);
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    opacity: 0;
    transform: translateX(30px) scale(0.95);
    pointer-events: none;
    visibility: hidden;
}

.auth-form.active {
    opacity: 1;
    transform: translateX(0) scale(1);
    pointer-events: all;
    visibility: visible;
    position: relative;
    animation: formSlideIn 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.auth-form.leaving {
    opacity: 0;
    transform: translateX(-30px) scale(0.95);
    pointer-events: none;
    animation: formSlideOut 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes formSlideIn {
    0% {
        opacity: 0;
        transform: translateX(40px) scale(0.95);
    }
    60% {
        opacity: 1;
        transform: translateX(-5px) scale(1);
    }
    100% {
        opacity: 1;
        transform: translateX(0) scale(1);
    }
}

@keyframes formSlideOut {
    0% {
        opacity: 1;
        transform: translateX(0) scale(1);
    }
    40% {
        opacity: 1;
        transform: translateX(-5px) scale(1);
    }
    100% {
        opacity: 0;
        transform: translateX(-40px) scale(0.95);
    }
}

/* Header Responsivo */
.form-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #8b5cf6 100%);
    color: white;
    padding: clamp(30px, 8vw, 40px) clamp(20px, 5vw, 30px) clamp(25px, 6vw, 30px);
    text-align: center;
    position: relative;
}

.form-header::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--secondary-color) 0%, #f59e0b 100%);
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: clamp(8px, 2vw, 12px);
    font-size: clamp(1.25rem, 4vw, 1.5rem);
    font-weight: 700;
    margin-bottom: clamp(12px, 3vw, 15px);
}

.logo i {
    font-size: clamp(1.5rem, 5vw, 2rem);
}

.form-header h1 {
    font-size: clamp(1.25rem, 4vw, 1.5rem);
    font-weight: 700;
    margin-bottom: clamp(6px, 1.5vw, 8px);
    line-height: 1.3;
}

.form-header p {
    opacity: 0.9;
    font-size: clamp(0.8rem, 2.5vw, 0.9rem);
    line-height: 1.4;
}

/* Conteúdo do Formulário Responsivo */
.form-content {
    padding: clamp(25px, 6vw, 30px) clamp(20px, 5vw, 30px);
}

/* Campos de Nome Responsivos */
.name-fields {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: clamp(10px, 3vw, 15px);
}

/* Grupos de Input Responsivos */
.input-group {
    position: relative;
    margin-bottom: clamp(15px, 4vw, 20px);
}

.input-group i {
    position: absolute;
    left: clamp(12px, 3vw, 15px);
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    transition: var(--transition);
    font-size: clamp(14px, 3vw, 16px);
}

.input-group input {
    width: 100%;
    padding: clamp(12px, 3vw, 15px) clamp(12px, 3vw, 15px) clamp(12px, 3vw, 15px) clamp(40px, 8vw, 45px);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: clamp(14px, 3vw, 16px);
    background: var(--bg-secondary);
    transition: var(--transition);
    outline: none;
    font-family: inherit;
}

/* Ajuste para campos sem ícone */
.name-fields .input-group:last-child input {
    padding-left: clamp(12px, 3vw, 15px);
}

.input-group input:focus {
    border-color: var(--primary-color);
    background: white;
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
    transform: translateY(-1px);
}

.input-group input:focus + i {
    color: var(--primary-color);
    transform: translateY(-50%) scale(1.1);
}

/* Força da Senha */
.password-strength {
    margin-top: clamp(6px, 1.5vw, 8px);
    height: 4px;
    background: var(--border-color);
    border-radius: 2px;
    overflow: hidden;
}

.strength-bar {
    height: 100%;
    width: 0%;
    background: var(--error-color);
    transition: var(--transition);
    border-radius: 2px;
}

/* Opções do Formulário Responsivas */
.form-options {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: clamp(20px, 5vw, 25px);
    flex-wrap: wrap;
    gap: clamp(8px, 2vw, 10px);
}

.checkbox {
    display: flex;
    align-items: center;
    gap: clamp(6px, 1.5vw, 8px);
    cursor: pointer;
    font-size: clamp(0.8rem, 2.5vw, 0.9rem);
    color: var(--text-secondary);
    line-height: 1.4;
}

.checkbox input {
    display: none;
}

.checkmark {
    width: clamp(16px, 4vw, 18px);
    height: clamp(16px, 4vw, 18px);
    border: 2px solid var(--border-color);
    border-radius: 4px;
    position: relative;
    transition: var(--transition);
    flex-shrink: 0;
}

.checkbox input:checked + .checkmark {
    background: var(--primary-color);
    border-color: var(--primary-color);
}

.checkbox input:checked + .checkmark::after {
    content: '✓';
    position: absolute;
    color: white;
    font-size: clamp(10px, 2.5vw, 12px);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.forgot-password {
    color: var(--primary-color);
    text-decoration: none;
    font-size: clamp(0.8rem, 2.5vw, 0.9rem);
    font-weight: 500;
    transition: var(--transition);
    white-space: nowrap;
}

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

/* Botões Responsivos */
.auth-btn {
    width: 100%;
    padding: clamp(12px, 3vw, 15px);
    border: none;
    border-radius: var(--border-radius);
    font-size: clamp(14px, 3vw, 16px);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: clamp(8px, 2vw, 10px);
    font-family: inherit;
}

.login-btn {
    background: var(--primary-color);
    color: white;
}

.signup-btn {
    background: var(--secondary-color);
    color: white;
}

.auth-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.auth-btn:active:not(:disabled) {
    transform: translateY(0);
}

.auth-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;
}

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

.btn-loader {
    display: none;
    width: clamp(16px, 4vw, 20px);
    height: clamp(16px, 4vw, 20px);
    border: 2px solid transparent;
    border-top: 2px solid currentColor;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.auth-btn.loading .btn-text {
    opacity: 0;
}

.auth-btn.loading .btn-loader {
    display: block;
}

/* Divisor Responsivo */
.divider {
    text-align: center;
    margin: clamp(20px, 5vw, 25px) 0;
    position: relative;
}

.divider::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: 1px;
    background: var(--border-color);
}

.divider span {
    background: white;
    padding: 0 clamp(10px, 2.5vw, 15px);
    color: var(--text-secondary);
    font-size: clamp(0.8rem, 2.5vw, 0.9rem);
}

/* Botões Sociais Responsivos */
.social-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: clamp(8px, 2vw, 10px);
    margin-bottom: clamp(20px, 5vw, 25px);
}

.social-btn {
    padding: clamp(10px, 2.5vw, 12px);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    background: white;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: clamp(6px, 1.5vw, 8px);
    font-size: clamp(0.8rem, 2.5vw, 0.9rem);
    font-weight: 500;
    font-family: inherit;
}

.social-btn:hover {
    border-color: var(--primary-color);
    transform: translateY(-1px);
}

.social-btn.google:hover {
    color: #db4437;
    border-color: #db4437;
}

.social-btn.facebook:hover {
    color: #4267B2;
    border-color: #4267B2;
}

/* Alternância entre Forms Responsiva */
.auth-switch {
    text-align: center;
    margin-top: clamp(20px, 5vw, 25px);
}

.auth-switch p {
    color: var(--text-secondary);
    font-size: clamp(0.8rem, 2.5vw, 0.9rem);
    line-height: 1.4;
}

.switch-btn {
    background: none;
    border: none;
    color: var(--primary-color);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: underline;
    font-family: inherit;
    font-size: inherit;
    padding: 2px 4px;
    border-radius: 4px;
}

.switch-btn:hover {
    color: var(--primary-dark);
    background: rgba(99, 102, 241, 0.1);
}

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

/* Estados de Loading e Disabled */
.auth-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

.input-group.error input {
    border-color: var(--error-color);
    background: rgba(239, 68, 68, 0.02);
}

.input-group.success input {
    border-color: var(--success-color);
    background: rgba(16, 185, 129, 0.02);
}

/* Mensagens de Erro */
.error-message {
    color: var(--error-color);
    font-size: clamp(0.7rem, 2vw, 0.8rem);
    margin-top: 4px;
    text-align: left;
    display: block;
}

/* ========== RESPONSIVIDADE AVANÇADA ========== */

/* Tablets */
@media (max-width: 768px) {
    .auth-container {
        max-width: min(450px, 90vw);
    }
    
    .name-fields {
        grid-template-columns: 1fr;
        gap: 12px;
    }
}

/* Mobile Landscape */
@media (max-width: 667px) and (orientation: landscape) {
    body {
        padding: 10px;
        align-items: flex-start;
    }
    
    .auth-container {
        max-width: 500px;
        margin: 20px auto;
    }
    
    .form-header {
        padding: 20px 25px 15px;
    }
    
    .form-content {
        padding: 20px 25px;
    }
    
    .auth-form {
        max-height: 80vh;
        overflow-y: auto;
    }
}

/* Telefones Pequenos */
@media (max-width: 375px) {
    .auth-container {
        max-width: 95vw;
    }
    
    .form-header {
        padding: 25px 15px 20px;
    }
    
    .form-content {
        padding: 20px 15px;
    }
    
    .social-buttons {
        grid-template-columns: 1fr;
    }
    
    .form-options {
        flex-direction: column;
        align-items: flex-start;
    }
}

/* Telefones Muito Pequenos */
@media (max-width: 320px) {
    .form-header {
        padding: 20px 12px 15px;
    }
    
    .form-content {
        padding: 15px 12px;
    }
    
    .input-group input {
        padding: 10px 10px 10px 35px;
    }
    
    .name-fields .input-group:last-child input {
        padding-left: 10px;
    }
}

/* Alturas Pequenas */
@media (max-height: 600px) {
    body {
        align-items: flex-start;
        padding-top: 20px;
        padding-bottom: 20px;
    }
    
    .auth-form {
        max-height: 90vh;
        overflow-y: auto;
    }
}

/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary: #1f2937;
        --bg-secondary: #374151;
        --text-primary: #f9fafb;
        --text-secondary: #d1d5db;
        --border-color: #4b5563;
    }
    
    .social-btn {
        background: #374151;
        color: var(--text-primary);
    }
}

/* High Contrast Support */
@media (prefers-contrast: high) {
    :root {
        --border-color: #000000;
        --shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    }
    
    .input-group input:focus {
        border-width: 3px;
    }
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .auth-form {
        transition: none;
    }
}

/* Print Styles */
@media print {
    .background,
    .social-buttons,
    .divider {
        display: none;
    }
    
    .auth-form {
        box-shadow: none;
        border: 1px solid #000;
    }
    
    .auth-btn {
        background: #000 !important;
        color: #fff !important;
    }
}