:root {
    --primary-blue: #1a73e8;
    --dark-blue: #0d47a1;
    --light-blue: #e8f0fe;
    --white: #ffffff;
    --gray: #f5f5f5;
    --dark-gray: #757575;
    --error-red: #d32f2f;
    --success-green: #388e3c;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
}

body {
    background-color: var(--gray);
    min-height: 100vh;
}

.container {
    display: flex;
    width: 100%;
    min-height: 100vh;
}

/* ========== LEFT PANEL ========== */
.left-panel {
    width: 50%;
    background: linear-gradient(135deg, var(--primary-blue), var(--dark-blue));
    color: var(--white);
    padding: 4rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.welcome-text h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    font-weight: 600;
}

.welcome-text p {
    font-size: 1.1rem;
    opacity: 0.9;
    line-height: 1.6;
    margin-bottom: 2rem;
}

.features {
    margin-top: 3rem;
}

.feature {
    display: flex;
    margin-bottom: 1.5rem;
    align-items: flex-start;
}

.feature i {
    font-size: 1.2rem;
    margin-right: 1rem;
    color: var(--white);
    background: rgba(255, 255, 255, 0.2);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.feature-text h3 {
    font-size: 1.1rem;
    margin-bottom: 0.3rem;
    font-weight: 500;
}

.feature-text p {
    font-size: 0.9rem;
    opacity: 0.8;
    line-height: 1.5;
}

/* ========== RIGHT PANEL ========== */
.right-panel {
    width: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.login-container {
    background: var(--white);
    padding: 3rem;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 450px;
}

.logo {
    display: flex;
    align-items: center;
    margin-bottom: 2rem;
}

.logo i {
    font-size: 2.5rem;
    margin-right: 1rem;
    color: var(--primary-blue);
}

.logo h1 {
    font-size: 1.8rem;
    font-weight: 600;
}

/* ========== TAB SYSTEM ========== */
.tab-system {
    display: flex;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid #ddd;
}

.tab-btn {
    padding: 10px 20px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    color: var(--dark-gray);
    position: relative;
    flex: 1;
    text-align: center;
}

.tab-btn.active {
    color: var(--primary-blue);
    font-weight: 500;
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-blue);
}

.tab-content {
    display: none;
}

/* ========== FORM ELEMENTS ========== */
.input-group {
    margin-bottom: 1.5rem;
    position: relative;
}

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: var(--dark-gray);
    font-weight: 500;
}

.input-group input,
.input-group select {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 1rem;
    transition: all 0.3s;
}

.input-group input:focus,
.input-group select:focus {
    border-color: var(--primary-blue);
    outline: none;
    box-shadow: 0 0 0 2px var(--light-blue);
}

.input-group input::placeholder {
    color: #aaa;
    font-size: 0.95rem;
}

.remember-forgot {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
    flex-wrap: wrap;
    gap: 10px;
}

.remember-me {
    display: flex;
    align-items: center;
}

.remember-me input[type="checkbox"] {
    width: 18px;
    height: 18px;
    margin-right: 0.5rem;
    cursor: pointer;
}

.remember-me label {
    cursor: pointer;
}

.forgot-password a {
    color: var(--primary-blue);
    text-decoration: none;
    font-weight: 500;
}

.forgot-password a:hover {
    text-decoration: underline;
}

.login-btn {
    width: 100%;
    padding: 14px;
    background-color: var(--primary-blue);
    color: var(--white);
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
}

.login-btn:hover {
    background-color: var(--dark-blue);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(26, 115, 232, 0.3);
}

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

.divider {
    margin: 1.5rem 0;
    text-align: center;
    position: relative;
    color: var(--dark-gray);
    font-size: 0.9rem;
}

.divider::before,
.divider::after {
    content: "";
    position: absolute;
    top: 50%;
    width: 45%;
    height: 1px;
    background-color: #ddd;
}

.divider::before {
    left: 0;
}

.divider::after {
    right: 0;
}

.social-login {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.social-btn {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--white);
    border: 1px solid #ddd;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 1.2rem;
    color: var(--dark-gray);
}

.social-btn:hover {
    background-color: var(--gray);
    transform: translateY(-2px);
    box-shadow: 0 5px 10px rgba(0,0,0,0.1);
}

.register-link {
    text-align: center;
    font-size: 0.95rem;
    color: var(--dark-gray);
    margin-top: 1.5rem;
}

.register-link a {
    color: var(--primary-blue);
    text-decoration: none;
    font-weight: 500;
}

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

/* ========== ALERTS ========== */
.alert {
    padding: 15px;
    border-radius: 6px;
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.alert i {
    font-size: 1.2rem;
}

.alert-error {
    background-color: #ffebee;
    color: var(--error-red);
    border-left: 4px solid var(--error-red);
}

.alert-success {
    background-color: #e8f5e9;
    color: var(--success-green);
    border-left: 4px solid var(--success-green);
}

/* ========== MOBILE RESPONSIVE ========== */

/* Tablet Devices (768px - 992px) */
@media (max-width: 992px) {
    .container {
        flex-direction: column;
    }
    
    .left-panel,
    .right-panel {
        width: 100%;
    }
    
    .left-panel {
        order: 2;
        padding: 3rem 2rem;
        text-align: center;
    }
    
    .right-panel {
        order: 1;
        padding: 2rem 1.5rem;
    }
    
    .feature {
        justify-content: center;
        text-align: left;
        max-width: 500px;
        margin-left: auto;
        margin-right: auto;
    }
    
    .welcome-text h2 {
        font-size: 2.2rem;
    }
    
    .welcome-text p {
        font-size: 1rem;
    }
}

/* Mobile Landscape (576px - 768px) */
@media (max-width: 768px) {
    .left-panel {
        padding: 2.5rem 1.5rem;
    }
    
    .right-panel {
        padding: 1.5rem;
    }
    
    .login-container {
        padding: 2rem;
    }
    
    .logo h1 {
        font-size: 1.5rem;
    }
    
    .logo i {
        font-size: 2rem;
    }
    
    .welcome-text h2 {
        font-size: 2rem;
    }
    
    .features {
        margin-top: 2rem;
    }
    
    .feature {
        margin-bottom: 1.2rem;
    }
    
    .tab-btn {
        padding: 8px 15px;
        font-size: 0.95rem;
    }
}

/* Mobile Portrait (below 576px) */
@media (max-width: 576px) {
    .left-panel {
        padding: 2rem 1rem;
    }
    
    .right-panel {
        padding: 1rem;
    }
    
    .login-container {
        padding: 1.5rem;
        border-radius: 8px;
    }
    
    .logo {
        margin-bottom: 1.5rem;
    }
    
    .logo i {
        font-size: 1.8rem;
        margin-right: 0.8rem;
    }
    
    .logo h1 {
        font-size: 1.3rem;
    }
    
    .welcome-text h2 {
        font-size: 1.6rem;
        margin-bottom: 0.8rem;
    }
    
    .welcome-text p {
        font-size: 0.95rem;
        margin-bottom: 1.5rem;
    }
    
    .features {
        margin-top: 1.5rem;
    }
    
    .feature {
        margin-bottom: 1rem;
    }
    
    .feature i {
        width: 35px;
        height: 35px;
        font-size: 1rem;
        margin-right: 0.8rem;
    }
    
    .feature-text h3 {
        font-size: 1rem;
    }
    
    .feature-text p {
        font-size: 0.85rem;
    }
    
    .tab-system {
        margin-bottom: 1.2rem;
    }
    
    .tab-btn {
        padding: 8px 10px;
        font-size: 0.9rem;
    }
    
    .input-group {
        margin-bottom: 1.2rem;
    }
    
    .input-group label {
        font-size: 0.85rem;
    }
    
    .input-group input,
    .input-group select {
        padding: 10px 12px;
        font-size: 0.95rem;
    }
    
    .remember-forgot {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }
    
    .forgot-password {
        align-self: flex-start;
    }
    
    .login-btn {
        padding: 12px;
        font-size: 0.95rem;
    }
    
    .alert {
        padding: 12px;
        font-size: 0.9rem;
    }
    
    .social-btn {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }
    
    .register-link {
        font-size: 0.9rem;
    }
}

/* Small Mobile (below 400px) */
@media (max-width: 400px) {
    .left-panel {
        padding: 1.5rem 1rem;
    }
    
    .login-container {
        padding: 1.2rem;
    }
    
    .logo i {
        font-size: 1.5rem;
    }
    
    .logo h1 {
        font-size: 1.1rem;
    }
    
    .welcome-text h2 {
        font-size: 1.4rem;
    }
    
    .tab-btn {
        padding: 6px 8px;
        font-size: 0.85rem;
    }
    
    .feature {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    .feature i {
        margin-right: 0;
        margin-bottom: 0.5rem;
    }
    
    .social-login {
        gap: 0.8rem;
    }
    
    .social-btn {
        width: 35px;
        height: 35px;
    }
}

/* Height-based media queries for very short devices */
@media (max-height: 600px) and (orientation: landscape) {
    .left-panel {
        padding: 1rem;
    }
    
    .right-panel {
        padding: 0.5rem;
    }
    
    .login-container {
        padding: 1rem;
    }
    
    .features {
        margin-top: 1rem;
    }
    
    .feature {
        margin-bottom: 0.5rem;
    }
    
    .welcome-text h2 {
        font-size: 1.3rem;
        margin-bottom: 0.3rem;
    }
    
    .welcome-text p {
        font-size: 0.85rem;
        margin-bottom: 1rem;
    }
}

/* Print styles */
@media print {
    .left-panel,
    .right-panel {
        width: 100%;
        page-break-inside: avoid;
    }
    
    .login-btn,
    .social-login,
    .register-link {
        display: none;
    }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
    .login-btn:hover,
    .social-btn:hover,
    .tab-btn:hover {
        transform: none;
        box-shadow: none;
    }
    
    .input-group input,
    .input-group select,
    .login-btn {
        font-size: 16px; /* Prevents zoom on focus in iOS */
    }
}

/* High resolution displays */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
    .login-container {
        border-width: 0.5px;
    }
}

/* Dark mode support (optional) */
@media (prefers-color-scheme: dark) {
    /* Add dark mode styles if needed */
}