/* ==================== CSS Variables & Colors ==================== */

:root {
    /* Primary Colors from LSB Logo */
    --color-primary-orange: #F5A623;      /* Vàng Cam */
    --color-primary-yellow: #FFC107;      /* Vàng */
    --color-primary-blue: #1E5A96;        /* Xanh Dương */
    --color-secondary-blue: #4A90E2;      /* Xanh Dương Nhạt */
    
    /* Neutral Colors */
    --color-white: #FFFFFF;
    --color-light-gray: #F5F5F5;
    --color-gray: #E0E0E0;
    --color-dark-gray: #666666;
    --color-text: #333333;
    --color-text-light: #666666;
    
    /* Status Colors */
    --color-success: #4CAF50;
    --color-error: #F44336;
    --color-warning: #FF9800;
    --color-info: #2196F3;
    
    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-full: 50%;
    
    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 300ms ease-in-out;
}

/* ==================== Reset & Base Styles ==================== */

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

html, body {
    width: 100%;
    height: 100%;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--color-text);
    background-color: var(--color-light-gray);
    line-height: 1.6;
}

/* ==================== Navbar ==================== */

.navbar {
    background: linear-gradient(135deg, var(--color-primary-blue) 0%, var(--color-secondary-blue) 100%);
    color: var(--color-white);
    padding: var(--spacing-md) 0;
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-size: 24px;
    font-weight: bold;
}

.logo {
    height: 40px;
    width: 40px;
    border-radius: var(--radius-full);
}

.brand-name {
    background: linear-gradient(135deg, var(--color-primary-orange) 0%, var(--color-primary-yellow) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.navbar-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.nav-link {
    color: var(--color-white);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.nav-link:hover {
    color: var(--color-primary-orange);
}

.nav-user {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

#userDisplay {
    font-weight: 500;
}

/* ==================== Buttons ==================== */

.btn {
    padding: var(--spacing-sm) var(--spacing-md);
    border: none;
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
}

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

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

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

.btn-secondary:hover {
    background-color: var(--color-dark-gray);
    color: var(--color-white);
}

.btn-logout {
    background-color: transparent;
    color: var(--color-white);
    border: 1px solid var(--color-white);
}

.btn-logout:hover {
    background-color: var(--color-primary-orange);
    border-color: var(--color-primary-orange);
}

.btn-send {
    background: linear-gradient(135deg, var(--color-primary-blue) 0%, var(--color-secondary-blue) 100%);
    color: var(--color-white);
    padding: var(--spacing-md) var(--spacing-lg);
}

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

.btn-block {
    width: 100%;
}

/* ==================== Forms ==================== */

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
    color: var(--color-text);
}

input[type="text"],
input[type="email"],
input[type="password"],
input[type="number"],
textarea {
    width: 100%;
    padding: var(--spacing-md);
    border: 1px solid var(--color-gray);
    border-radius: var(--radius-md);
    font-size: 14px;
    font-family: inherit;
    transition: border-color var(--transition-fast);
}

input[type="text"]:focus,
input[type="email"]:focus,
input[type="password"]:focus,
input[type="number"]:focus,
textarea:focus {
    outline: none;
    border-color: var(--color-primary-blue);
    box-shadow: 0 0 0 3px rgba(30, 90, 150, 0.1);
}

textarea {
    resize: vertical;
    min-height: 100px;
}

/* ==================== Pages ==================== */

.page {
    display: none;
}

.page.active {
    display: block;
}

/* ==================== Login Page ==================== */

#loginPage {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background: linear-gradient(135deg, var(--color-primary-blue) 0%, var(--color-secondary-blue) 100%);
}

.login-container {
    width: 100%;
    max-width: 400px;
    padding: var(--spacing-md);
}

.login-box {
    background: var(--color-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    text-align: center;
}

.login-logo {
    height: 80px;
    width: 80px;
    margin-bottom: var(--spacing-md);
    border-radius: var(--radius-full);
}

.login-box h1 {
    font-size: 28px;
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(135deg, var(--color-primary-blue) 0%, var(--color-primary-orange) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.login-subtitle {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-lg);
}

.error-message {
    color: var(--color-error);
    padding: var(--spacing-md);
    background-color: rgba(244, 67, 54, 0.1);
    border-radius: var(--radius-md);
    margin-top: var(--spacing-md);
    display: none;
}

.error-message.show {
    display: block;
}

/* ==================== Main App ==================== */

.main-app {
    display: flex;
    flex-direction: column;
    height: calc(100vh - 70px);
}

/* ==================== Chat Page ==================== */

.chat-container {
    display: flex;
    flex-direction: column;
    height: 100%;
    max-width: 1000px;
    margin: 0 auto;
    width: 100%;
}

.chat-history {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.chat-welcome {
    text-align: center;
    margin-top: auto;
    margin-bottom: auto;
    color: var(--color-text-light);
}

.chat-welcome h2 {
    color: var(--color-primary-blue);
    margin-bottom: var(--spacing-md);
}

.chat-message {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.chat-message.user {
    justify-content: flex-end;
}

.chat-message.assistant {
    justify-content: flex-start;
}

.message-content {
    max-width: 70%;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
}

.chat-message.user .message-content {
    background: linear-gradient(135deg, var(--color-primary-orange) 0%, var(--color-primary-yellow) 100%);
    color: var(--color-white);
}

.chat-message.assistant .message-content {
    background-color: var(--color-white);
    border: 1px solid var(--color-gray);
}

.message-image {
    margin-top: var(--spacing-md);
    border-radius: var(--radius-lg);
    max-width: 100%;
    box-shadow: var(--shadow-md);
}

.chat-input-area {
    padding: var(--spacing-lg);
    background-color: var(--color-white);
    border-top: 1px solid var(--color-gray);
}

.input-group {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-end;
}

.file-upload {
    position: relative;
}

#referenceImage {
    display: none;
}

.upload-label {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background-color: var(--color-light-gray);
    border: 1px solid var(--color-gray);
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 20px;
    transition: all var(--transition-fast);
}

.upload-label:hover {
    background-color: var(--color-gray);
}

#messageInput {
    flex: 1;
    min-height: 44px;
    max-height: 120px;
}

.btn-send {
    height: 44px;
    white-space: nowrap;
}

.image-preview {
    margin-top: var(--spacing-md);
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.preview-item {
    position: relative;
    width: 80px;
    height: 80px;
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.preview-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.preview-remove {
    position: absolute;
    top: 4px;
    right: 4px;
    background-color: var(--color-error);
    color: var(--color-white);
    border: none;
    border-radius: var(--radius-full);
    width: 24px;
    height: 24px;
    cursor: pointer;
    font-size: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* ==================== Gallery Page ==================== */

.gallery-container {
    padding: var(--spacing-lg);
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.gallery-container h2 {
    margin-bottom: var(--spacing-lg);
    color: var(--color-primary-blue);
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.gallery-item {
    background-color: var(--color-white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
    cursor: pointer;
}

.gallery-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.gallery-item-image {
    width: 100%;
    height: 250px;
    object-fit: cover;
    background-color: var(--color-light-gray);
}

.gallery-item-info {
    padding: var(--spacing-md);
}

.gallery-item-prompt {
    font-size: 12px;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-sm);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.gallery-item-date {
    font-size: 12px;
    color: var(--color-text-light);
}

.loading {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--color-text-light);
}

/* ==================== Pagination ==================== */

.pagination {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-lg);
}

.pagination button {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--color-gray);
    background-color: var(--color-white);
    color: var(--color-text);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.pagination button:hover {
    background-color: var(--color-primary-blue);
    color: var(--color-white);
    border-color: var(--color-primary-blue);
}

.pagination button.active {
    background: linear-gradient(135deg, var(--color-primary-orange) 0%, var(--color-primary-yellow) 100%);
    color: var(--color-white);
    border-color: var(--color-primary-orange);
}

/* ==================== Admin Panel ==================== */

.admin-container {
    padding: var(--spacing-lg);
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.admin-tabs {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    border-bottom: 2px solid var(--color-gray);
}

.tab-btn {
    padding: var(--spacing-md) var(--spacing-lg);
    background: none;
    border: none;
    border-bottom: 3px solid transparent;
    color: var(--color-text-light);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.tab-btn:hover {
    color: var(--color-primary-blue);
}

.tab-btn.active {
    color: var(--color-primary-blue);
    border-bottom-color: var(--color-primary-blue);
}

.admin-tab {
    display: none;
}

.admin-tab.active {
    display: block;
}

.admin-table {
    width: 100%;
    border-collapse: collapse;
    background-color: var(--color-white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.admin-table thead {
    background: linear-gradient(135deg, var(--color-primary-blue) 0%, var(--color-secondary-blue) 100%);
    color: var(--color-white);
}

.admin-table th,
.admin-table td {
    padding: var(--spacing-md);
    text-align: left;
    border-bottom: 1px solid var(--color-gray);
}

.admin-table tbody tr:hover {
    background-color: var(--color-light-gray);
}

.admin-table .btn {
    padding: var(--spacing-sm);
    font-size: 12px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.stat-card {
    background-color: var(--color-white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border-left: 4px solid var(--color-primary-orange);
}

.stat-card h3 {
    color: var(--color-text-light);
    font-size: 14px;
    margin-bottom: var(--spacing-sm);
}

.stat-card .value {
    font-size: 28px;
    font-weight: bold;
    color: var(--color-primary-blue);
}

/* ==================== Modals ==================== */

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    animation: fadeIn var(--transition-normal);
}

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

.modal-content {
    background-color: var(--color-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    max-width: 500px;
    width: 90%;
    box-shadow: var(--shadow-lg);
    animation: slideUp var(--transition-normal);
}

.close {
    color: var(--color-text-light);
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    transition: color var(--transition-fast);
}

.close:hover {
    color: var(--color-error);
}

/* ==================== Animations ==================== */

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

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

/* ==================== Responsive ==================== */

@media (max-width: 768px) {
    .navbar-menu {
        gap: var(--spacing-md);
    }

    .nav-link {
        display: none;
    }

    .gallery-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    }

    .message-content {
        max-width: 90%;
    }

    .input-group {
        flex-direction: column;
    }

    #messageInput {
        min-height: 80px;
    }

    .btn-send {
        width: 100%;
    }

    .admin-table {
        font-size: 12px;
    }

    .admin-table th,
    .admin-table td {
        padding: var(--spacing-sm);
    }
}

@media (max-width: 480px) {
    .navbar-brand {
        gap: var(--spacing-sm);
    }

    .brand-name {
        font-size: 18px;
    }

    .logo {
        height: 30px;
        width: 30px;
    }

    .gallery-grid {
        grid-template-columns: 1fr;
    }

    .login-box {
        padding: var(--spacing-lg);
    }

    .login-logo {
        height: 60px;
        width: 60px;
    }
}