:root {
    --primary: #007AFF;
    --primary-dark: #0056CC;
    --primary-light: #E5F1FF;
    --text: #1D1D1F;
    --text-secondary: #6E6E73;
    --text-tertiary: #86868B;
    --bg: #F5F5F7;
    --bg-white: #FFFFFF;
    --bg-secondary: #F0F0F5;
    --border: #D2D2D7;
    --border-light: #E5E5EA;
    --success: #34C759;
    --warning: #FF9500;
    --error: #FF3B30;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text);
    background-color: var(--bg);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.navbar {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-light);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 0.75rem 0;
}

.nav-container {
    max-width: 980px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text);
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--transition);
}

.nav-brand:hover {
    opacity: 0.7;
}

.app-icon {
    width: 28px;
    height: 28px;
    color: var(--primary);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    padding: 4px 0;
}

.nav-links a:hover {
    color: var(--primary);
}

.nav-links a.active {
    color: var(--primary);
}

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary);
    border-radius: 2px;
}

.nav-admin {
    color: var(--text-tertiary) !important;
    font-size: 0.85rem;
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: var(--transition);
}

.main-content {
    flex: 1;
    max-width: 980px;
    width: 100%;
    margin: 0 auto;
    padding: 3rem 20px;
}

.page-header {
    text-align: center;
    padding: 3rem 0;
}

.page-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 0.75rem;
    letter-spacing: -0.02em;
}

.page-header p {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.card {
    background: var(--bg-white);
    border-radius: var(--radius-md);
    padding: 2rem;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.card:hover {
    box-shadow: var(--shadow-md);
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.quick-links {
    margin-top: 3rem;
}

.quick-links h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--text);
}

.link-card {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.25rem 1.5rem;
    background: var(--bg-white);
    border-radius: var(--radius-md);
    text-decoration: none;
    color: var(--text);
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.link-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.link-icon {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.link-icon.help {
    background: var(--primary-light);
    color: var(--primary);
}

.link-icon.privacy {
    background: #E8F5E9;
    color: var(--success);
}

.link-icon.feedback {
    background: #FFF3E0;
    color: var(--warning);
}

.link-icon svg {
    width: 22px;
    height: 22px;
}

.link-text h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 2px;
}

.link-text p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.feedback-section {
    margin-top: 4rem;
    padding-top: 3rem;
    border-top: 1px solid var(--border-light);
}

.feedback-container {
    max-width: 600px;
    margin: 0 auto;
}

.feedback-header {
    text-align: center;
    margin-bottom: 2rem;
}

.feedback-header h2 {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.feedback-header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.feedback-form {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 0.5rem;
}

.form-group input[type="text"],
.form-group input[type="email"],
.form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-family: inherit;
    transition: var(--transition);
    background: var(--bg-white);
}

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

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-tertiary);
}

.rating-input {
    display: flex;
    gap: 0.25rem;
    flex-direction: row-reverse;
    justify-content: flex-end;
}

.rating-input input {
    display: none;
}

.rating-input label {
    font-size: 1.75rem;
    color: var(--border);
    cursor: pointer;
    transition: var(--transition);
    margin-bottom: 0;
    line-height: 1;
}

.rating-input label:hover,
.rating-input label:hover ~ label,
.rating-input input:checked ~ label {
    color: #FFD700;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 1.75rem;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
}

.btn-primary {
    background: var(--primary);
    color: white;
    width: 100%;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text);
}

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

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.login-container {
    max-width: 400px;
    margin: 0 auto;
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.login-form .form-group {
    margin-bottom: 1.25rem;
}

.login-form label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 0.5rem;
}

.login-form input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-family: inherit;
    transition: var(--transition);
    background: var(--bg-white);
}

.login-form input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.flash-messages {
    margin-bottom: 1.5rem;
}

.flash {
    padding: 1rem 1.25rem;
    border-radius: var(--radius-sm);
    margin-bottom: 0.75rem;
    font-size: 0.95rem;
}

.flash-success {
    background: #E8F5E9;
    color: #1B5E20;
    border: 1px solid #C8E6C9;
}

.flash-error {
    background: #FFEBEE;
    color: #B71C1C;
    border: 1px solid #FFCDD2;
}

.footer {
    background: var(--bg-white);
    border-top: 1px solid var(--border-light);
    padding: 2rem 0;
    margin-top: auto;
}

.footer-container {
    max-width: 980px;
    margin: 0 auto;
    padding: 0 20px;
    text-align: center;
}

.footer-brand {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 1rem;
}

.footer-icon {
    width: 20px;
    height: 20px;
    color: var(--primary);
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary);
}

.footer-copyright {
    color: var(--text-tertiary);
    font-size: 0.8rem;
}

.privacy-content,
.help-content {
    max-width: 720px;
    margin: 0 auto;
}

.privacy-content h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 2rem;
    text-align: center;
}

.privacy-content h2 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text);
    margin-top: 2rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-light);
}

.privacy-content p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.privacy-content ul,
.privacy-content ol {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.privacy-content li {
    margin-bottom: 0.5rem;
    line-height: 1.6;
}

.privacy-content strong {
    color: var(--text);
}

.help-hero {
    text-align: center;
    padding: 3rem 2rem;
    background: linear-gradient(135deg, var(--primary-light) 0%, #E8F5E9 100%);
    border-radius: var(--radius-lg);
    margin-bottom: 3rem;
}

.help-hero h1 {
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.help-hero p {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 500px;
    margin: 0 auto;
}

.screenshots {
    margin: 2rem 0;
}

.screenshots img {
    width: 100%;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    margin-bottom: 1rem;
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-white);
        flex-direction: column;
        padding: 1rem;
        gap: 0;
        border-bottom: 1px solid var(--border-light);
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links a {
        padding: 0.75rem 0;
        width: 100%;
    }

    .mobile-menu-btn {
        display: flex;
    }

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

    .form-row {
        grid-template-columns: 1fr;
    }

    .feedback-form {
        padding: 1.5rem;
    }

    .card {
        padding: 1.5rem;
    }
}

.feedback-table-container {
    background: var(--bg-white);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.feedback-table {
    width: 100%;
    border-collapse: collapse;
}

.feedback-table th {
    background: var(--bg-secondary);
    padding: 1rem;
    text-align: left;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-bottom: 1px solid var(--border-light);
}

.feedback-table td {
    padding: 1rem;
    border-bottom: 1px solid var(--border-light);
    vertical-align: top;
}

.feedback-row:last-child td {
    border-bottom: none;
}

.feedback-row:hover {
    background: var(--bg-secondary);
}

.feedback-time {
    white-space: nowrap;
}

.time-primary {
    font-weight: 600;
    color: var(--text);
    font-size: 0.9rem;
}

.time-secondary {
    font-size: 0.8rem;
    color: var(--text-tertiary);
}

.user-name {
    font-weight: 600;
    color: var(--text);
}

.user-email {
    font-size: 0.85rem;
    color: var(--text-tertiary);
}

.feedback-version {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.feedback-rating .stars {
    color: #FFD700;
    font-size: 0.9rem;
    letter-spacing: 2px;
}

.feedback-content {
    max-width: 300px;
}

.content-text {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.status-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

.status-badge.status-new {
    background: var(--primary-light);
    color: var(--primary);
}

.status-badge.status-replied {
    background: #E8F5E9;
    color: var(--success);
}

.feedback-actions-cell {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    white-space: nowrap;
}

.status-form select {
    padding: 0.4rem 0.6rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    background: var(--bg-white);
    cursor: pointer;
}

.btn-delete {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    padding: 0.4rem;
    opacity: 0.6;
    transition: var(--transition);
}

.btn-delete:hover {
    opacity: 1;
}

.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    background: var(--bg-white);
    border-radius: var(--radius-md);
}

.empty-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.back-link {
    margin-top: 2rem;
}

@media (max-width: 900px) {
    .feedback-table-container {
        overflow-x: auto;
    }
    
    .feedback-table {
        min-width: 700px;
    }
}

.filter-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    align-items: center;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: var(--bg-white);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.filter-select {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    background: var(--bg-white);
    cursor: pointer;
    min-width: 140px;
}

.filter-select:focus {
    outline: none;
    border-color: var(--primary);
}

.search-input {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    flex: 1;
    min-width: 200px;
}

.search-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.sort-header {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    color: var(--text);
    text-decoration: none;
    font-weight: 600;
}

.sort-header:hover {
    color: var(--primary);
}

.sort-icon {
    font-size: 0.75rem;
    color: var(--primary);
}

.pagination-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 1.5rem;
    padding: 1rem;
    background: var(--bg-white);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.pagination-info {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.pagination-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.pagination-controls .btn {
    min-width: 36px;
    text-align: center;
}

.pagination-controls .btn.active {
    background: var(--primary);
    color: white;
    pointer-events: none;
}

.pagination-controls .btn.disabled {
    opacity: 0.4;
    pointer-events: none;
}

.pagination-ellipsis {
    padding: 0 0.5rem;
    color: var(--text-tertiary);
}

.per-page-select {
    padding: 0.4rem 0.6rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    background: var(--bg-white);
    margin-left: 0.5rem;
}

@media (max-width: 768px) {
    .filter-bar {
        flex-direction: column;
        align-items: stretch;
    }
    
    .filter-select,
    .search-input {
        width: 100%;
    }
    
    .pagination-bar {
        flex-direction: column;
        text-align: center;
    }
    
    .pagination-controls {
        justify-content: center;
    }
}