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

body {
    font-family: 'Open Sans', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: 40px;
    color: white;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 10px;
}

.logo i {
    font-size: 2.5rem;
    color: #ffd700;
}

.logo h1 {
    font-size: 2.5rem;
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
    font-weight: 300;
}

/* Cards */
.card {
    background: white;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    margin-bottom: 30px;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.15);
}

.card-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 20px 25px;
    border-bottom: none;
}

.card-header h2 {
    font-size: 1.4rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 10px;
}

.card-header i {
    font-size: 1.2rem;
}

.card-body {
    padding: 25px;
}

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

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

.form-group label {
    font-weight: 600;
    color: #555;
    display: flex;
    align-items: center;
    gap: 8px;
}

.form-group input {
    padding: 12px 15px;
    border: 2px solid #e1e5e9;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    background: #f8f9fa;
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
    background: white;
}

/* Buttons */
.btn {
    padding: 12px 25px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    justify-content: center;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-danger {
    background: linear-gradient(135deg, #ff6b6b 0%, #ee5a52 100%);
    color: white;
}

.btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255, 107, 107, 0.4);
}

.btn-success {
    background: linear-gradient(135deg, #51cf66 0%, #40c057 100%);
    color: white;
}

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(81, 207, 102, 0.4);
}

/* Key Info Display */
.key-info {
    display: grid;
    gap: 15px;
}

.info-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 15px;
    background: #f8f9fa;
    border-radius: 8px;
    border-left: 4px solid #667eea;
}

.info-label {
    font-weight: 600;
    color: #555;
    display: flex;
    align-items: center;
    gap: 8px;
}

.info-value {
    font-weight: 500;
    color: #333;
}

.status-active {
    color: #51cf66;
    font-weight: 600;
}

.status-inactive {
    color: #ff6b6b;
    font-weight: 600;
}

.status-expired {
    color: #ffa726;
    font-weight: 600;
}

/* Warning Text */
.warning-text {
    background: #fff3cd;
    border: 1px solid #ffeaa7;
    color: #856404;
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

/* Loading Spinner */
.loading-spinner {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    color: white;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255,255,255,0.3);
    border-top: 4px solid white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 20px;
}

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

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1001;
}

.toast {
    background: white;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
    padding: 15px 20px;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 10px;
    min-width: 300px;
    animation: slideIn 0.3s ease;
}

.toast.success {
    border-left: 4px solid #51cf66;
}

.toast.error {
    border-left: 4px solid #ff6b6b;
}

.toast.warning {
    border-left: 4px solid #ffa726;
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* Utility Classes */
.hidden {
    display: none !important;
}

.text-center {
    text-align: center;
}

.text-success {
    color: #51cf66;
}

.text-danger {
    color: #ff6b6b;
}

.text-warning {
    color: #ffa726;
}

/* Footer */
.footer {
    text-align: center;
    color: rgba(255,255,255,0.8);
    margin-top: 40px;
    padding: 20px;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    .logo h1 {
        font-size: 2rem;
    }
    
    .card-body {
        padding: 20px;
    }
    
    .info-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 5px;
    }
    
    .toast {
        min-width: 250px;
    }
}

@media (max-width: 480px) {
    .logo {
        flex-direction: column;
        gap: 10px;
    }
    
    .logo h1 {
        font-size: 1.8rem;
    }
    
    .btn {
        width: 100%;
    }
}