:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --bg: #f8fafc;
    --surface: #ffffff;
    --text: #0f172a;
    --text-secondary: #64748b;
    --border: #e2e8f0;
    --success: #10b981;
    --error: #ef4444;
    --radius: 12px;
    --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.1);
    --transition: all 0.2s ease;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: var(--primary);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

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

.logo h1 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text);
}

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

.user-info {
    position: absolute;
    top: 2rem;
    right: 2rem;
}

.user-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--text);
    cursor: pointer;
    transition: var(--transition);
}

.user-badge:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.user-badge.guest {
    color: var(--text-secondary);
}

/* Main Layout */
.main {
    display: grid;
    grid-template-columns: 400px 1fr;
    gap: 2rem;
    align-items: start;
}

/* Input Section */
.input-section {
    background: var(--surface);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    position: sticky;
    top: 2rem;
}

.prompt-container {
    margin-bottom: 1.25rem;
}

.prompt-label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: var(--text);
}

.prompt-input {
    width: 100%;
    padding: 0.875rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 0.9rem;
    font-family: inherit;
    resize: vertical;
    transition: var(--transition);
    background: var(--bg);
    min-height: 100px;
}

.prompt-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.prompt-input::placeholder {
    color: #94a3b8;
}

.options-section {
    margin-bottom: 1.25rem;
}

.option-group {
    margin-bottom: 1rem;
}

.option-label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: var(--text);
}

.size-options,
.count-options {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.size-btn,
.count-btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--surface);
    color: var(--text-secondary);
    font-size: 0.85rem;
    cursor: pointer;
    transition: var(--transition);
}

.size-btn:hover,
.count-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.size-btn.active,
.count-btn.active {
    border-color: var(--primary);
    background: var(--primary);
    color: white;
}

.generate-btn {
    width: 100%;
    padding: 0.875rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.generate-btn:hover:not(:disabled) {
    background: var(--primary-hover);
}

.generate-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.spinner {
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* Result Section */
.result-section {
    background: var(--surface);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    min-height: 400px;
}

.gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.placeholder {
    grid-column: 1 / -1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 300px;
    color: var(--text-secondary);
}

.placeholder-icon {
    margin-bottom: 1rem;
    opacity: 0.3;
}

.placeholder p {
    font-size: 0.95rem;
}

/* Image Cards */
.image-card {
    position: relative;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.image-card img {
    width: 100%;
    height: auto;
    display: block;
}

.image-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(transparent, rgba(0,0,0,0.7));
    padding: 1rem;
    opacity: 0;
    transition: var(--transition);
}

.image-card:hover .image-overlay {
    opacity: 1;
}

.image-actions {
    display: flex;
    gap: 0.5rem;
    justify-content: flex-end;
}

.action-btn {
    padding: 0.5rem;
    background: rgba(255,255,255,0.2);
    border: none;
    border-radius: 6px;
    color: white;
    cursor: pointer;
    transition: var(--transition);
}

.action-btn:hover {
    background: rgba(255,255,255,0.3);
}

/* Messages */
.error-message {
    background: #fef2f2;
    border: 1px solid #fecaca;
    color: var(--error);
    padding: 0.875rem;
    border-radius: 8px;
    margin-top: 1rem;
    font-size: 0.875rem;
}

.success-message {
    background: #f0fdf4;
    border: 1px solid #bbf7d0;
    color: var(--success);
    padding: 0.875rem;
    border-radius: 8px;
    margin-top: 1rem;
    font-size: 0.875rem;
}

/* History Section */
.history-section {
    margin-top: 2rem;
    background: var(--surface);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

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

.history-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text);
}

.history-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1rem;
}

.history-placeholder {
    grid-column: 1 / -1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 200px;
    color: var(--text-secondary);
}

.history-placeholder .placeholder-icon {
    margin-bottom: 1rem;
    opacity: 0.3;
}

.history-item {
    background: var(--surface);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border);
}

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

.history-item-image-wrapper {
    overflow: hidden;
    position: relative;
}

.history-item-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
    transition: transform 0.3s ease;
    cursor: pointer;
}

.history-item:hover .history-item-image {
    transform: scale(1.03);
}

.preview-btn {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 48px;
    height: 48px;
    background: rgba(0,0,0,0.5);
    border: 2px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    color: white;
    cursor: pointer;
    opacity: 0;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.history-item:hover .preview-btn {
    opacity: 1;
}

.preview-btn:hover {
    background: var(--primary);
    border-color: white;
}

.history-item-info {
    padding: 1rem;
}

.history-item-prompt {
    font-size: 0.875rem;
    color: var(--text);
    margin-bottom: 0.75rem;
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.history-item-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border);
}

.history-item-meta span {
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.meta-user {
    font-weight: 500;
    color: var(--primary);
}

.history-item-actions {
    display: flex;
    gap: 0.5rem;
}

.history-action-btn {
    flex: 1;
    padding: 0.5rem;
    background: var(--bg);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.8rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.history-action-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(37, 99, 235, 0.05);
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    max-width: 90vw;
    max-height: 90vh;
    position: relative;
    animation: modalIn 0.3s ease;
}

@keyframes modalIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.modal-image {
    max-width: 100%;
    max-height: 80vh;
    object-fit: contain;
    border-radius: 8px;
}

.modal-close {
    position: absolute;
    top: -40px;
    right: 0;
    width: 36px;
    height: 36px;
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: 50%;
    color: white;
    font-size: 1.25rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-close:hover {
    background: rgba(255,255,255,0.2);
}

.modal-prompt-container {
    margin-top: 1rem;
    max-width: 700px;
    width: 100%;
    background: rgba(255,255,255,0.1);
    border-radius: 8px;
    padding: 1rem;
    max-height: 150px;
    overflow-y: auto;
}

.modal-prompt-label {
    color: rgba(255,255,255,0.6);
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 0.5rem;
}

.modal-prompt {
    color: white;
    font-size: 0.9rem;
    line-height: 1.6;
    word-wrap: break-word;
}

/* Username Dialog */
.username-dialog {
    background: var(--surface);
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    max-width: 400px;
    width: 90%;
    animation: modalIn 0.3s ease;
}

.username-dialog h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.username-dialog p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1.25rem;
}

.dialog-input-group {
    margin-bottom: 0.75rem;
}

.dialog-input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 0.9rem;
    font-family: inherit;
    transition: var(--transition);
}

.dialog-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.dialog-error {
    color: var(--error);
    font-size: 0.85rem;
    min-height: 1.25rem;
    margin-bottom: 1rem;
}

.dialog-buttons {
    display: flex;
    gap: 0.75rem;
    justify-content: flex-end;
}

.dialog-btn {
    padding: 0.625rem 1.25rem;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.dialog-btn.cancel {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
}

.dialog-btn.cancel:hover {
    border-color: var(--text);
    color: var(--text);
}

.dialog-btn.confirm {
    background: var(--primary);
    border: 1px solid var(--primary);
    color: white;
}

.dialog-btn.confirm:hover {
    background: var(--primary-hover);
}

/* Footer */
.footer {
    text-align: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* Responsive */
@media (max-width: 1024px) {
    .main {
        grid-template-columns: 1fr;
    }

    .input-section {
        position: static;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    .header {
        margin-bottom: 1.5rem;
    }

    .logo h1 {
        font-size: 1.25rem;
    }

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

@media (max-width: 480px) {
    .logo {
        flex-direction: column;
        gap: 0.5rem;
    }

    .logo-icon {
        width: 36px;
        height: 36px;
    }

    .user-info {
        position: static;
        margin-top: 1rem;
    }
}