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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    color: #333;
    line-height: 1.6;
    min-height: 100vh;
}

/* Header Styles */
.header {
    background: linear-gradient(135deg, #dc2626 0%, #b91c1c 100%);
    box-shadow: 0 4px 20px rgba(220, 38, 38, 0.2);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar {
    padding: 1rem 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

.nav-menu {
    display: flex;
    gap: 1rem;
}

.nav-link {
    color: white;
    text-decoration: none;
    font-weight: 500;
    font-size: 1rem;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.nav-link::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 ease;
}

.nav-link:hover::before {
    left: 100%;
}

.nav-link:hover,
.nav-link.active {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-2px);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 50%;
    width: 70%;
    height: 3px;
    background: #fbbf24;
    transform: translateX(-50%);
    border-radius: 2px;
}

.nav-auth-container {
    display: flex;
    align-items: center;
}

.nav-auth {
    display: flex;
    gap: 1rem;
}

.auth-link {
    color: white;
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1.5rem;
    border-radius: 25px;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.auth-link:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.login-btn {
    background: #facc15;
    color: #b91c1c;
    font-weight: 600;
    border-color: #facc15;
}

.login-btn:hover {
    background: #f59e0b;
    border-color: #f59e0b;
    box-shadow: 0 4px 15px rgba(245, 158, 11, 0.4);
}

.profile-menu {
    position: relative;
}

.profile-toggle {
    background: none;
    border: none;
    cursor: pointer;
    border-radius: 50%;
    transition: transform 0.3s ease;
}

.profile-toggle:hover {
    transform: scale(1.1);
}

.profile-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.5);
    object-fit: cover;
    display: block;
}

.profile-dropdown {
    position: absolute;
    top: 120%;
    right: 0;
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
    width: 200px;
    overflow: hidden;
    z-index: 1001;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.3s ease;
    display: none;
}

.profile-dropdown.show {
    display: block;
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    color: #374151;
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

.dropdown-item:hover {
    background: #f3f4f6;
    color: #dc2626;
}

.dropdown-divider {
    height: 1px;
    background: #e5e7eb;
    margin: 0.25rem 0;
}

.mobile-auth {
    display: none;
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.mobile-menu-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
}

/* Main Content */
.main-content {
    padding: 2rem 0;
    min-height: calc(100vh - 74px);
}

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

/* Page Header */
.page-header {
    text-align: center;
    margin-bottom: 3rem;
    animation: fadeInUp 0.8s ease;
}

.header-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.header-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #dc2626, #b91c1c);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2rem;
    box-shadow: 0 10px 30px rgba(220, 38, 38, 0.3);
    animation: pulse 2s infinite;
}

.header-text h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 0.5rem;
}

.header-text p {
    font-size: 1.1rem;
    color: #6b7280;
    max-width: 500px;
}

/* Feedback Container */
.feedback-container {
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    animation: fadeInUp 0.8s ease 0.2s both;
}

.feedback-form {
    padding: 2rem;
}

/* Form Sections */
.form-section {
    margin-bottom: 2.5rem;
    animation: slideInLeft 0.6s ease;
}

.form-section:nth-child(even) {
    animation: slideInRight 0.6s ease;
}

.section-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid #f3f4f6;
    position: relative;
}

.section-header::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 60px;
    height: 2px;
    background: linear-gradient(90deg, #dc2626, #b91c1c);
    border-radius: 1px;
}

.section-header i {
    color: #dc2626;
    font-size: 1.2rem;
}

.section-header h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: #1f2937;
}

/* Form Groups */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    font-weight: 500;
    color: #374151;
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.required-mark {
    color: #dc2626;
    font-weight: 600;
}

.input-wrapper {
    position: relative;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid #e5e7eb;
    border-radius: 12px;
    font-size: 0.95rem;
    transition: all 0.3s ease;
    background: #fafafa;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #dc2626;
    background: white;
    box-shadow: 0 0 0 3px rgba(220, 38, 38, 0.1);
    transform: translateY(-2px);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
    font-family: inherit;
}

.anonymous-option {
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
    color: #6b7280;
}

.anonymous-option input[type="checkbox"] {
    width: auto;
    margin: 0;
}

.char-count {
    text-align: right;
    font-size: 0.8rem;
    color: #6b7280;
    margin-top: 0.5rem;
}

/* Checkbox Group */
.checkbox-group {
    display: grid;
    gap: 1rem;
}

.checkbox-item {
    position: relative;
}

.checkbox-item input[type="checkbox"] {
    position: absolute;
    opacity: 0;
    cursor: pointer;
}

.checkbox-item label {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    border: 2px solid #e5e7eb;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #fafafa;
    margin-bottom: 0;
}

.checkbox-item label:hover {
    border-color: #dc2626;
    background: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(220, 38, 38, 0.1);
}

.checkbox-item input[type="checkbox"]:checked + label {
    border-color: #dc2626;
    background: linear-gradient(135deg, #fef2f2, #fee2e2);
}

.checkbox-custom {
    width: 20px;
    height: 20px;
    border: 2px solid #d1d5db;
    border-radius: 4px;
    position: relative;
    transition: all 0.3s ease;
    flex-shrink: 0;
}

.checkbox-item input[type="checkbox"]:checked + label .checkbox-custom {
    background: #dc2626;
    border-color: #dc2626;
}

.checkbox-item input[type="checkbox"]:checked + label .checkbox-custom::after {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-size: 0.8rem;
    font-weight: bold;
}

.checkbox-text {
    font-weight: 500;
    color: #374151;
}

/* File Upload */
.file-upload-area {
    border: 2px dashed #d1d5db;
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
    background: #fafafa;
}

.file-upload-area:hover {
    border-color: #dc2626;
    background: #fef2f2;
}

.file-upload-area.dragover {
    border-color: #dc2626;
    background: #fef2f2;
    transform: scale(1.02);
}

.upload-content i {
    font-size: 2.5rem;
    color: #9ca3af;
    margin-bottom: 1rem;
}

.upload-content p {
    font-size: 1rem;
    color: #6b7280;
    margin-bottom: 0.5rem;
}

.upload-link {
    color: #dc2626;
    font-weight: 500;
    cursor: pointer;
}

.upload-link:hover {
    text-decoration: underline;
}

.upload-content small {
    color: #9ca3af;
    font-size: 0.85rem;
}

.file-list {
    margin-top: 1rem;
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem;
    background: #f3f4f6;
    border-radius: 8px;
    margin-bottom: 0.5rem;
    animation: slideInUp 0.3s ease;
}

.file-info {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.file-info i {
    color: #dc2626;
}

.file-name {
    font-weight: 500;
    color: #374151;
}

.file-size {
    font-size: 0.8rem;
    color: #6b7280;
}

.file-remove {
    background: none;
    border: none;
    color: #ef4444;
    cursor: pointer;
    padding: 0.25rem;
    border-radius: 4px;
    transition: all 0.2s ease;
}

.file-remove:hover {
    background: #fee2e2;
}

/* Form Actions */
.form-actions {
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
    padding-top: 2rem;
    border-top: 2px solid #f3f4f6;
    animation: fadeInUp 0.6s ease 0.4s both;
}

.btn-primary,
.btn-secondary {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 2rem;
    border: none;
    border-radius: 12px;
    font-weight: 500;
    font-size: 0.95rem;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, #dc2626, #b91c1c);
    color: white;
    box-shadow: 0 4px 15px rgba(220, 38, 38, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(220, 38, 38, 0.4);
}

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

.btn-secondary {
    background: #f3f4f6;
    color: #6b7280;
    border: 2px solid #e5e7eb;
}

.btn-secondary:hover {
    background: #e5e7eb;
    color: #374151;
    transform: translateY(-2px);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 2000;
    animation: fadeIn 0.3s ease;
}

.modal.show {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    max-width: 400px;
    width: 90%;
    text-align: center;
    animation: scaleIn 0.3s ease;
}

.modal-header {
    margin-bottom: 1.5rem;
}

.modal-header i {
    font-size: 3rem;
    color: #10b981;
    margin-bottom: 1rem;
}

.modal-header h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: #1f2937;
}

.modal-body p {
    color: #6b7280;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.modal-actions {
    display: flex;
    justify-content: center;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: block;
    }
    
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: linear-gradient(135deg, #dc2626 0%, #b91c1c 100%);
        flex-direction: column;
        padding: 1rem 0;
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    }
    
    .nav-menu.mobile-open {
        display: flex;
    }
    
    .nav-link {
        padding: 1rem 1.5rem;
    }
    
    .desktop-auth {
        display: none;
    }
    
    .mobile-auth {
        display: flex;
        flex-direction: column;
        gap: 0.5rem;
        margin-top: 1rem;
        padding: 1rem 1.5rem 0;
        border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

    .header-text h1 {
        font-size: 2rem;
    }

    .container {
        padding: 0 15px;
    }

    .feedback-form {
        padding: 1.5rem;
    }

    .form-actions {
        flex-direction: column;
    }

    .btn-primary,
    .btn-secondary {
        justify-content: center;
    }

    .anonymous-option {
        position: static;
        transform: none;
        margin-top: 0.5rem;
        justify-content: flex-start;
    }
}

@media (max-width: 480px) {
    .nav-container {
        padding: 0 15px;
    }

    .header-text h1 {
        font-size: 1.75rem;
    }

    .header-text p {
        font-size: 1rem;
    }

    .feedback-form {
        padding: 1rem;
    }

    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
}