/* Material Design Reset and Variables */
:root {
    --primary-color: #1976d2;
    --primary-dark: #1565c0;
    --primary-light: #42a5f5;
    --accent-color: #ff4081;
    --success-color: #4caf50;
    --error-color: #f44336;
    --warning-color: #ff9800;
    --text-primary: #212121;
    --text-secondary: #757575;
    --text-disabled: #bdbdbd;
    --divider: #e0e0e0;
    --background: #fafafa;
    --surface: #ffffff;
    --shadow-1: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-2: 0 4px 8px rgba(0,0,0,0.12);
    --shadow-3: 0 8px 16px rgba(0,0,0,0.14);
    --shadow-4: 0 16px 32px rgba(0,0,0,0.16);
}

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

body {
    font-family: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    overflow-x: hidden;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Login Container */
.login-container {
    width: 100%;
    max-width: 450px;
    padding: 20px;
    animation: fadeInUp 0.6s ease-out;
}

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

/* Card */
.card {
    background: var(--surface);
    border-radius: 12px;
    box-shadow: var(--shadow-4);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.2);
}

.card-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 32px 24px;
    text-align: center;
}

.card-header i.material-icons {
    font-size: 48px;
    margin-bottom: 12px;
    opacity: 0.9;
}

.card-header h2 {
    font-size: 28px;
    font-weight: 500;
    margin-bottom: 8px;
    letter-spacing: 0.5px;
}

.card-header .subtitle {
    font-size: 14px;
    opacity: 0.9;
    font-weight: 300;
}

.card-body {
    padding: 32px 24px;
}

/* Input Groups */
.input-group {
    position: relative;
    margin-bottom: 28px;
}

.input-group i.material-icons {
    position: absolute;
    left: 0;
    top: 20px;
    color: var(--text-secondary);
    font-size: 20px;
    transition: color 0.3s ease;
}

.input-group input {
    width: 100%;
    padding: 18px 12px 8px 36px;
    border: none;
    border-bottom: 2px solid var(--divider);
    font-size: 16px;
    background: transparent;
    transition: border-color 0.3s ease;
    outline: none;
}

.input-group input:focus {
    border-bottom-color: var(--primary-color);
}

.input-group input:focus ~ i.material-icons {
    color: var(--primary-color);
}

.input-group label {
    position: absolute;
    left: 36px;
    top: 16px;
    color: var(--text-secondary);
    font-size: 16px;
    pointer-events: none;
    transition: all 0.3s ease;
}

.input-group input:focus ~ label,
.input-group input:valid ~ label {
    top: 0;
    font-size: 12px;
    color: var(--primary-color);
}

/* Buttons */
.btn {
    width: 100%;
    padding: 14px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.3s ease;
    margin-bottom: 12px;
    box-shadow: var(--shadow-2);
}

.btn:hover {
    box-shadow: var(--shadow-3);
    transform: translateY(-2px);
}

.btn:active {
    transform: translateY(0);
    box-shadow: var(--shadow-1);
}

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

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-dark) 0%, #0d47a1 100%);
}

.btn-secondary {
    background: white;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    box-shadow: none;
}

.btn-secondary:hover {
    background: var(--primary-light);
    color: white;
    border-color: var(--primary-light);
}

.btn i.material-icons {
    font-size: 20px;
}

/* Error Message */
.error-message {
    background: #ffebee;
    color: var(--error-color);
    padding: 12px 16px;
    border-radius: 6px;
    margin-bottom: 16px;
    font-size: 14px;
    display: none;
    align-items: center;
    gap: 8px;
    animation: shake 0.5s ease;
}

.error-message:not(:empty) {
    display: flex;
}

.error-message::before {
    content: 'error';
    font-family: 'Material Icons';
    font-size: 20px;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

/* Success Message */
.success-message {
    background: #e8f5e9;
    color: var(--success-color);
    padding: 12px 16px;
    border-radius: 6px;
    margin-bottom: 16px;
    font-size: 14px;
    display: none;
    align-items: center;
    gap: 8px;
}

.success-message:not(:empty) {
    display: flex;
}

.success-message::before {
    content: 'check_circle';
    font-family: 'Material Icons';
    font-size: 20px;
}

/* Responsive Design */
@media (max-width: 768px) {
    .login-container {
        padding: 12px;
    }
    
    .card-header {
        padding: 24px 16px;
    }
    
    .card-header h2 {
        font-size: 24px;
    }
    
    .card-body {
        padding: 24px 16px;
    }
}
    font-weight: bold;
}

.close:hover,
.close:focus {
    color: black;
    text-decoration: none;
    cursor: pointer;
}

@media (max-width: 600px) {
    .container {
        width: 95%;
    }

    input[type="submit"] {
        width: 100%;
    }
}