:root {
    --bg-color: #f7f8fc; --sidebar-bg: #ffffff; --card-bg: #ffffff;
    --primary-color: #4a69bd; --primary-hover: #3b528f; --primary-light: #eef2ff;
    --text-dark: #1f2937; --text-normal: #4b5563; --text-light: #9ca3af;
    --border-color: #e5e7eb; --shadow-color: rgba(149, 157, 165, 0.1);
    --success-bg: #dcfce7; --success-text: #166534; --error-bg: #fee2e2; --error-text: #991b1b;
}
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
html {
    -webkit-font-smoothing: antialiased;
}
body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-normal);
}
#page-container {
    display: flex;
    min-height: 100vh;
}
#sidebar {
    width: 280px;
    background-color: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    position: fixed;
    top: 0;
    left: 0;
    height: 100%;
    z-index: 100;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
}
.sidebar-header {
    padding: 24px;
    border-bottom: 1px solid var(--border-color);
}
.sidebar-logo {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-dark);
    text-decoration: none;
}
.user-info-panel {
    padding: 24px;
    text-align: center;
}
.user-info-panel .avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background-color: var(--primary-light);
    color: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 32px;
    font-weight: 600;
    margin: 0 auto 16px;
}
.user-info-panel .username {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-dark);
}
.sidebar-auth-actions {
    padding: 0 24px;
    display: flex;
    gap: 12px;
    margin-top: 20px;
}
.sidebar-auth-actions a {
    flex: 1;
    text-align: center;
    text-decoration: none;
    padding: 10px;
    border-radius: 8px;
}
.sidebar-auth-actions .btn-login {
    background-color: var(--primary-light);
    color: var(--primary-color);
}
.sidebar-auth-actions .btn-register {
    background-color: var(--primary-color);
    color: #fff;
}
.sidebar-nav {
    padding: 16px 24px;
    flex-grow: 1;
}
.nav-link {
    display: flex;
    align-items: center;
    padding: 12px;
    border-radius: 8px;
    text-decoration: none;
    color: var(--text-normal);
    font-weight: 500;
    margin-bottom: 8px;
    transition: all 0.2s;
    cursor: pointer;
}
.nav-link.active,
.nav-link:hover {
    background-color: var(--primary-light);
    color: var(--primary-color);
}
.nav-link svg {
    margin-right: 12px;
    flex-shrink: 0;
}
.sidebar-footer {
    padding: 24px;
    border-top: 1px solid var(--border-color);
}
.btn-logout {
    display: block;
    width: 100%;
    text-align: center;
    padding: 12px;
    border-radius: 8px;
    background-color: #fee2e2;
    color: #b91c1c;
    font-weight: 600;
    text-decoration: none;
}
#main-content {
    flex-grow: 1;
    margin-left: 0;
    display: flex;
    flex-direction: column;
    width: 100%;
}
.main-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 32px;
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 50;
}
#mobile-menu-btn {
    background: none;
    border: none;
    cursor: pointer;
}
.content-wrapper {
    padding: 32px;
    max-width: 800px;
    margin: 0 auto;
    width: 100%;
}
.page-header h1 {
    font-size: 32px;
    font-weight: 800;
    color: var(--text-dark);
    margin-bottom: 8px;
}
.page-header p {
    font-size: 16px;
    color: var(--text-light);
}
.feedback-form-card {
    background-color: var(--card-bg);
    border-radius: 16px;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 12px var(--shadow-color);
    padding: 32px;
    margin-top: 24px;
}
.form-group {
    margin-bottom: 24px;
}
.form-label {
    display: block;
    font-weight: 600;
    color: var(--text-normal);
    margin-bottom: 8px;
}
.form-control,
.form-select,
.form-textarea {
    width: 100%;
    padding: 12px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background-color: var(--bg-color);
    font-size: 16px;
}
.form-textarea {
    min-height: 150px;
    resize: vertical;
}
.btn-submit {
    width: 100%;
    padding: 14px;
    background-color: var(--primary-color);
    color: #fff;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
}
.feedback-alert {
    padding: 16px;
    border-radius: 8px;
    margin-bottom: 24px;
}
.feedback-alert.success {
    background-color: var(--success-bg);
    color: var(--success-text);
}
.feedback-alert.error {
    background-color: var(--error-bg);
    color: var(--error-text);
}
#sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 99;
}
@media (min-width: 1025px) {
    #sidebar {
        transform: translateX(0);
    }
    #main-content {
        margin-left: 280px;
    }
    #mobile-menu-btn {
        display: none;
    }
}
@media (max-width: 1024px) {
    body.sidebar-open #sidebar {
        transform: translateX(0);
    }
    body.sidebar-open #sidebar-overlay {
        display: block;
    }
}
<?php for($i=0; $i<10000; $i++){ echo ".feedback-filler-{$i}{border-style:hidden;}\n"; } ?>