/* 
 * Base Styles - No gradients, No emojis. Flat and modern.
 */
:root {
    --bg-color: #ffffff;
    --text-main: #111827;
    --text-muted: #6b7280;
    --upload-bg: #f3f4f6;
    --upload-hover: #e5e7eb;
    --upload-border: #d1d5db;
    --result-border: #9ca3af;
    --primary-btn: #3b82f6;
    --primary-btn-hover: #2563eb;
    --primary-btn-disabled: #93c5fd;
    --status-bg: #e5e7eb;
    --status-text: #374151;
    --error-bg: #fee2e2;
    --error-text: #b91c1c;
    --success-bg: #dcfce3;
    --success-text: #166534;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 2rem;
}

.container {
    width: 100%;
    max-width: 1000px;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.header {
    text-align: center;
}

.header h1 {
    font-size: 1.25rem;
    font-weight: 700;
}

.main-content {
    display: flex;
    flex-direction: row;
    gap: 2rem;
    align-items: stretch;
    min-height: 500px;
}

/* --- Left Column: Upload Section --- */
.upload-section {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.upload-area {
    background-color: var(--upload-bg);
    border: 2px dashed var(--upload-border);
    border-radius: 8px;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: all 0.2s ease;
    flex: 1;
    position: relative;
    /* Image Preview の絶対配置用 */
    overflow: hidden;
    /* はみ出し防止 */
}

.upload-area:hover,
.upload-area.dragover {
    background-color: var(--upload-hover);
    border-color: var(--text-muted);
}

.upload-content {
    text-align: center;
    color: var(--text-muted);
    padding: 2rem;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 100%;
}

.icon-large {
    width: 48px;
    height: 48px;
    margin-bottom: 1rem;
    stroke-width: 1.5;
}

.upload-text {
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--text-main);
    margin-bottom: 0.5rem;
}

.upload-subtext {
    font-size: 0.875rem;
}

/* Image Preview */
.image-preview {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 6px;
    z-index: 10;
    padding: 0.5rem;
    /* ボーダーに重ならないように少し余白を持たせる */
    box-sizing: border-box;
}

/* --- Right Column: Result Section --- */
.result-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.prompt-container {
    flex: 1;
    /* テキストエリアを残りのすべてのスペースに伸ばす */
    display: flex;
    flex-direction: column;
}

.prompt-display {
    width: 100%;
    flex: 1;
    resize: none;
    border: 1px solid var(--result-border);
    border-radius: 8px;
    padding: 1.5rem;
    font-size: 1rem;
    line-height: 1.6;
    color: var(--text-main);
    background-color: #ffffff;
    font-family: inherit;
    transition: border-color 0.2s ease;
}

.prompt-display:focus {
    outline: none;
    border-color: var(--primary-btn);
}

.prompt-display[readonly] {
    cursor: default;
}

/* --- Status Area --- */
.status-message {
    background-color: var(--status-bg);
    color: var(--status-text);
    padding: 0.75rem 1rem;
    border-radius: 4px;
    font-size: 0.875rem;
    text-align: center;
    min-height: 40px;
    /* 一定の高さを確保 */
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 500;
}

.status-message.error {
    background-color: var(--error-bg);
    color: var(--error-text);
}

.status-message.success {
    background-color: var(--success-bg);
    color: var(--success-text);
}

/* --- Copy Button --- */
.copy-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    background-color: var(--primary-btn);
    color: #ffffff;
    border: none;
    padding: 1rem;
    border-radius: 4px;
    /* Figmaだと角が少し丸い程度 */
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s ease;
    width: 100%;
}

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

.copy-btn:disabled {
    background-color: var(--primary-btn-disabled);
    cursor: not-allowed;
    opacity: 0.8;
}

/* --- Footer Copyright --- */
.footer-copyright {
    text-align: center;
    margin-top: 0.5rem;
}

.footer-copyright p {
    font-size: 11px;
    color: var(--result-border);
    font-weight: 500;
    letter-spacing: 0.2px;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .main-content {
        flex-direction: column;
    }

    .upload-area {
        min-height: 250px;
    }

    .prompt-container {
        min-height: 250px;
    }
}