/* ===== Base Styles ===== */
:root {
    /* Color Scheme */
    --primary: #1874ab;
    --primary-light: #35a0cf;
    --primary-hover: #14618f;
    --white: #ffffff;
    --white-transparent: rgba(255, 255, 255, 0.9);
    --text-primary: #2d3748;
    --text-secondary: #4a5568;
    --bg-light: #f7fafc;
    --border-color: #e2e8f0;
    
    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    
    /* Typography */
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.5rem;
    --text-2xl: 1.8rem;
    
    /* Effects */
    --border-radius: 8px;
    --border-radius-lg: 12px;
    --box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Reset & Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===== Layout Styles ===== */
.auth-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: var(--space-md);
    position: relative;
    overflow: hidden;
}

.auth-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('../images/login_background.png');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    filter: brightness(0.95);
    z-index: -1;
}

.auth-card {
    background: var(--white-transparent);
    padding: var(--space-xl);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--box-shadow);
    max-width: 480px;
    width: 100%;
    text-align: center;
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(8px);
}

.auth-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 6px;
    background: linear-gradient(90deg, var(--primary) 0%, var(--primary-light) 100%);
}

/* ===== Component Styles ===== */
.auth-header {
    margin-bottom: var(--space-lg);
    transition: var(--transition);
}

.auth-logo {
    height: 80px;
    margin-bottom: var(--space-md);
    transition: var(--transition);
}

.auth-title {
    font-size: var(--text-xl);
    font-weight: 600;
    margin-bottom: var(--space-sm);
    color: var(--text-primary);
    letter-spacing: -0.5px;
}

.auth-description {
    font-size: var(--text-base);
    line-height: 1.6;
    margin-bottom: var(--space-lg);
    color: var(--text-secondary);
}

/* Form Styles */
.auth-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.form-group {
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: var(--space-xs);
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    color: var(--text-primary);
    font-size: var(--text-base);
    transition: var(--transition);
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-light);
    box-shadow: 0 0 0 3px rgba(24, 116, 171, 0.1);
}

/* Button Styles */
.auth-button {
    background-color: var(--primary);
    color: white;
    padding: 0.875rem 2rem;
    font-size: var(--text-base);
    font-weight: 500;
    border-radius: var(--border-radius);
    border: none;
    cursor: pointer;
    transition: var(--transition);
    width: 100%;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    gap: var(--space-xs);
    margin-top: var(--space-sm);
}

.auth-button:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(24, 116, 171, 0.2);
}

.auth-button:active {
    transform: translateY(0);
}

/* Provider Badge */
.provider-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    margin: var(--space-md) 0;
    background: var(--white);
    border: 1px solid var(--border-color);
    transition: var(--transition);
    gap: var(--space-sm);
    width: fit-content;
    margin-left: auto;
    margin-right: auto;
}

.provider-badge:hover {
    background: rgba(24, 116, 171, 0.05);
    border-color: var(--primary-light);
}

.provider-badge img {
    height: 24px;
    width: 24px;
}

.provider-name {
    font-weight: 500;
    color: var(--text-primary);
}

/* Footer Styles */
.auth-footer {
    margin-top: var(--space-lg);
    font-size: 0.875rem;
    color: var(--text-secondary);
}

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

.auth-footer a:hover {
    text-decoration: underline;
}

/* ===== Responsive Styles ===== */
@media (max-width: 640px) {
    :root {
        --space-xl: 2rem;
        --space-lg: 1.5rem;
    }
    
    .auth-card {
        padding: var(--space-lg);
    }
    
    .auth-logo {
        height: 64px;
    }
    
    .auth-title {
        font-size: var(--text-lg);
    }
}

@media (max-width: 480px) {
    .auth-container {
        padding: var(--space-sm);
    }
    
    .auth-card {
        padding: var(--space-md);
        backdrop-filter: blur(4px);
    }
}