/* ============================================================
   GPT-Image 生图工作台 — ChatGPT 官网风格
   ============================================================ */
:root {
    --bg: #ffffff;
    --bg-elev: #f9f9f9;
    --sidebar-bg: #f9f9f9;
    --border: #e4e4e7;
    --text: #0d0d0d;
    --text-2: #5d5d5d;
    --text-3: #8f8f8f;
    --accent: #0d0d0d;
    --accent-text: #ffffff;
    --input-bg: #ffffff;
    --composer-bg: #ffffff;
    --composer-shadow: 0 4px 24px rgba(0, 0, 0, 0.08), 0 0 0 1px var(--border);
    --hover: #ececec;
    --danger: #dc2626;
    --success: #16a34a;
    --radius-lg: 24px;
    --radius-md: 14px;
    --radius-sm: 10px;
}

body.dark-mode {
    --bg: #212121;
    --bg-elev: #2f2f2f;
    --sidebar-bg: #171717;
    --border: #3a3a3a;
    --text: #ececec;
    --text-2: #b4b4b4;
    --text-3: #8f8f8f;
    --accent: #ffffff;
    --accent-text: #0d0d0d;
    --input-bg: #303030;
    --composer-bg: #303030;
    --composer-shadow: 0 4px 24px rgba(0, 0, 0, 0.4), 0 0 0 1px var(--border);
    --hover: #3a3a3a;
}

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

html, body { height: 100%; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    background: var(--bg);
    color: var(--text);
    font-size: 15px;
    line-height: 1.5;
    transition: background 0.2s, color 0.2s;
}

.app { display: flex; height: 100vh; height: 100dvh; overflow: hidden; }

/* ==================== 侧边栏 ==================== */
.sidebar {
    width: 240px;
    flex-shrink: 0;
    background: var(--sidebar-bg);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 12px 10px;
}

.sidebar-top, .sidebar-bottom { display: flex; flex-direction: column; gap: 2px; }

.nav-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 100%;
    padding: 10px 12px;
    border: none;
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text);
    font-size: 14px;
    cursor: pointer;
    text-align: left;
    transition: background 0.15s;
}

.nav-btn:hover { background: var(--hover); }
.nav-btn.active { background: var(--hover); font-weight: 600; }
.nav-btn .icon { font-size: 17px; width: 22px; text-align: center; }

/* ==================== 主区域 ==================== */
.main { flex: 1; display: flex; flex-direction: column; min-width: 0; }

.topbar {
    display: flex;
    align-items: baseline;
    gap: 12px;
    padding: 16px 28px;
    flex-shrink: 0;
}

.topbar-title { font-size: 17px; font-weight: 600; }
.topbar-sub { font-size: 12.5px; color: var(--text-3); }

/* ==================== 标签页 ==================== */
.tab-pane { display: none; flex-direction: column; flex: 1; min-height: 0; }
.tab-pane.active { display: flex; }

/* ==================== 新建生成（对话流） ==================== */
#create-tab { display: flex; flex-direction: column; flex: 1; min-height: 0; }

.chat-scroll { flex: 1; overflow-y: auto; }

.chat-column {
    max-width: 768px;
    margin: 0 auto;
    padding: 24px 24px 12px;
    display: flex;
    flex-direction: column;
}

/* 空状态 */
.empty-state {
    text-align: center;
    margin: auto;
    padding: 60px 20px;
    color: var(--text-2);
}
.empty-state .empty-illustration { font-size: 44px; margin-bottom: 14px; }
.empty-state h2 { font-size: 26px; font-weight: 600; color: var(--text); margin-bottom: 8px; }
.empty-state.small { padding: 40px 0; }
.empty-state.small p { color: var(--text-3); }

/* 加载中 */
.loading-state {
    text-align: center;
    margin: auto;
    padding: 60px 20px;
    color: var(--text-2);
}
.loading-state h3 { margin-top: 16px; font-size: 16px; color: var(--text); }
.loading-state p { margin-top: 6px; font-size: 13px; color: var(--text-3); }

.spinner {
    width: 36px; height: 36px;
    margin: 0 auto;
    border: 3px solid var(--border);
    border-top-color: var(--text);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* 结果 */
.results-container { padding-bottom: 8px; }
.results-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 12px;
}
.results-tag { font-size: 13px; font-weight: 600; color: var(--text-2); }

.generated-images {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 12px;
}

.image-card {
    position: relative;
    border-radius: var(--radius-md);
    overflow: hidden;
    background: var(--bg-elev);
    cursor: pointer;
}
.image-card > img {
    width: 100%;
    display: block;
    aspect-ratio: 1;
    object-fit: cover;
}
.image-card-overlay {
    position: absolute;
    inset: auto 0 0 0;
    display: flex;
    justify-content: center;
    gap: 8px;
    padding: 12px;
    background: linear-gradient(transparent, rgba(0, 0, 0, 0.55));
    opacity: 0;
    transition: opacity 0.15s;
}
.image-card:hover .image-card-overlay { opacity: 1; }
.overlay-btn {
    width: 34px; height: 34px;
    border: none;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.92);
    cursor: pointer;
    font-size: 14px;
    transition: transform 0.1s;
}
.overlay-btn:hover { transform: scale(1.08); }

/* 错误 */
.error-state {
    text-align: center;
    margin: auto;
    padding: 60px 20px;
    color: var(--text-2);
}
.error-state .error-icon { font-size: 38px; }
.error-state h3 { margin-top: 12px; color: var(--text); }
.error-state p { margin: 8px 0 16px; color: var(--danger); word-break: break-all; }

/* ==================== Composer（底部输入区） ==================== */
.composer-wrap {
    flex-shrink: 0;
    padding: 8px 24px 14px;
}

.composer {
    max-width: 768px;
    margin: 0 auto;
    background: var(--composer-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--composer-shadow);
    padding: 12px 14px 10px;
    transition: box-shadow 0.15s, border-color 0.15s;
}
.composer.dragover { outline: 2px dashed var(--text-3); outline-offset: 4px; }

.ref-strip {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 10px;
}

.ref-item {
    position: relative;
    width: 72px; height: 72px;
    border-radius: var(--radius-sm);
    overflow: hidden;
    border: 1px solid var(--border);
}
.ref-item img { width: 100%; height: 100%; object-fit: cover; display: block; }
.ref-item .ref-remove {
    position: absolute;
    top: 3px; right: 3px;
    width: 20px; height: 20px;
    border: none;
    border-radius: 50%;
    background: rgba(0, 0, 0, 0.65);
    color: #fff;
    font-size: 11px;
    cursor: pointer;
    display: flex; align-items: center; justify-content: center;
}
.ref-item .ref-remove:hover { background: var(--danger); }

.composer-input {
    width: 100%;
    border: none;
    outline: none;
    resize: none;
    background: transparent;
    color: var(--text);
    font: inherit;
    font-size: 15.5px;
    padding: 6px 4px;
    max-height: 200px;
}
.composer-input::placeholder { color: var(--text-3); }

.composer-tools {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    margin-top: 8px;
    flex-wrap: wrap;
}
.tools-left { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.tools-right { display: flex; align-items: center; gap: 10px; }

.icon-btn {
    width: 36px; height: 36px;
    border: none;
    border-radius: 50%;
    background: transparent;
    font-size: 16px;
    cursor: pointer;
    color: var(--text);
    transition: background 0.15s;
}
.icon-btn:hover { background: var(--hover); }

.drop-zone { display: flex; }

.tool-select {
    appearance: none;
    border: 1px solid var(--border);
    background: var(--input-bg);
    color: var(--text);
    font-size: 13px;
    padding: 7px 26px 7px 12px;
    border-radius: 999px;
    cursor: pointer;
    transition: background 0.15s;
    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='10' height='6'><path d='M1 1l4 4 4-4' stroke='%238f8f8f' stroke-width='1.5' fill='none' stroke-linecap='round'/></svg>");
    background-repeat: no-repeat;
    background-position: right 10px center;
}
.tool-select:hover { background-color: var(--hover); }

.char-count { font-size: 12px; color: var(--text-3); font-variant-numeric: tabular-nums; }

.send-btn {
    width: 38px; height: 38px;
    border: none;
    border-radius: 50%;
    background: var(--accent);
    color: var(--accent-text);
    font-size: 18px;
    cursor: pointer;
    transition: opacity 0.15s, transform 0.1s;
}
.send-btn:hover { opacity: 0.85; }
.send-btn:active { transform: scale(0.94); }
.send-btn:disabled { opacity: 0.4; cursor: not-allowed; }

.composer-hint {
    max-width: 768px;
    margin: 8px auto 0;
    text-align: center;
    font-size: 11.5px;
    color: var(--text-3);
}

/* ==================== 高级选项面板 ==================== */
.advanced-panel {
    background: var(--bg-elev);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 14px;
    margin-bottom: 12px;
}
.advanced-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 12px;
}
.adv-field { display: flex; flex-direction: column; gap: 5px; font-size: 12.5px; color: var(--text-2); }
.adv-field-wide { grid-column: 1 / -1; }
.adv-field em { font-style: normal; color: var(--text); font-weight: 600; }

.adv-select {
    appearance: none;
    border: 1px solid var(--border);
    background: var(--input-bg);
    color: var(--text);
    font-size: 13.5px;
    padding: 8px 10px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='10' height='6'><path d='M1 1l4 4 4-4' stroke='%238f8f8f' stroke-width='1.5' fill='none' stroke-linecap='round'/></svg>");
    background-repeat: no-repeat;
    background-position: right 10px center;
}

.adv-textarea {
    border: 1px solid var(--border);
    background: var(--input-bg);
    color: var(--text);
    font: inherit;
    font-size: 13.5px;
    padding: 8px 10px;
    border-radius: var(--radius-sm);
    resize: vertical;
    outline: none;
}
.adv-textarea:focus, .adv-select:focus { border-color: var(--text-3); }

.adv-field input[type="range"] { accent-color: var(--text); width: 100%; }

/* ==================== 历史 / 收藏页 ==================== */
.page-scroll { flex: 1; overflow-y: auto; }
.page-column { max-width: 960px; margin: 0 auto; padding: 24px; }
.page-title { font-size: 20px; font-weight: 600; margin-bottom: 18px; }

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 14px;
}
.gallery-grid .empty-state { grid-column: 1 / -1; }

.grid-item {
    border-radius: var(--radius-md);
    overflow: hidden;
    background: var(--bg-elev);
    border: 1px solid var(--border);
    cursor: pointer;
    transition: transform 0.12s;
}
.grid-item:hover { transform: translateY(-2px); }
.grid-item img { width: 100%; aspect-ratio: 1; object-fit: cover; display: block; }
.grid-item-info {
    padding: 8px 10px;
    font-size: 12px;
    color: var(--text-2);
    display: flex;
    flex-direction: column;
    gap: 2px;
}

/* ==================== 模态框 ==================== */
.modal {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    padding: 20px;
}
.modal-card {
    background: var(--bg);
    border-radius: 18px;
    width: 100%;
    max-width: 440px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}
.modal-wide { max-width: 880px; }

.modal-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 22px 0;
}
.modal-head h2 { font-size: 17px; }
.modal-close {
    border: none;
    background: transparent;
    font-size: 24px;
    color: var(--text-3);
    cursor: pointer;
    line-height: 1;
}
.modal-close:hover { color: var(--text); }

.modal-body { padding: 16px 22px 20px; }
.modal-foot { padding: 0 22px 20px; display: flex; justify-content: flex-end; }

.modal-field { display: flex; flex-direction: column; gap: 6px; margin-bottom: 14px; font-size: 13px; color: var(--text-2); }
.modal-input {
    border: 1px solid var(--border);
    background: var(--input-bg);
    color: var(--text);
    font-size: 14px;
    padding: 9px 12px;
    border-radius: var(--radius-sm);
    outline: none;
}
.modal-input:focus { border-color: var(--text-3); }

.check-row {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 9px 0;
    cursor: pointer;
    font-size: 14px;
}
.check-row input { accent-color: var(--text); width: 16px; height: 16px; }

.modal-note { font-size: 12px; color: var(--text-3); margin-top: 8px; }

/* 详情 */
.detail-layout { display: flex; gap: 20px; flex-wrap: wrap; }
.detail-image { flex: 1; min-width: 280px; }
.detail-image img { width: 100%; border-radius: var(--radius-md); display: block; }
.detail-info { flex: 1; min-width: 260px; }
.detail-group { margin-bottom: 18px; }
.detail-group h4 { font-size: 13px; color: var(--text-3); font-weight: 600; margin-bottom: 8px; }
.detail-group p { font-size: 13.5px; margin-bottom: 6px; word-break: break-all; }
.detail-group b { color: var(--text-2); font-weight: 500; }
.detail-actions { display: flex; flex-wrap: wrap; gap: 8px; }

/* 通用小按钮 */
.chip-btn {
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text);
    font-size: 13px;
    padding: 7px 14px;
    border-radius: 999px;
    cursor: pointer;
    transition: background 0.15s;
}
.chip-btn:hover { background: var(--hover); }

/* ==================== 通知 ==================== */
.notification {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--accent);
    color: var(--accent-text);
    padding: 10px 20px;
    border-radius: 999px;
    font-size: 13.5px;
    box-shadow: 0 6px 24px rgba(0, 0, 0, 0.2);
    z-index: 200;
    animation: drop-in 0.2s ease-out;
}
.notification.error { background: var(--danger); color: #fff; }
.notification.success { background: var(--success); color: #fff; }

@keyframes drop-in {
    from { opacity: 0; transform: translate(-50%, -8px); }
    to { opacity: 1; transform: translate(-50%, 0); }
}

/* ==================== 滚动条 ==================== */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-3); }

/* ==================== 响应式：平板 / 手机 ==================== */
@media (max-width: 720px) {
    /* 整体改为上下结构：顶部标题 + 内容 + 底部导航栏 */
    .app { flex-direction: column; }

    /* 侧边栏 → 底部导航栏（ChatGPT 手机版风格） */
    .sidebar {
        order: 2;
        width: 100%;
        flex-direction: row;
        justify-content: space-around;
        align-items: center;
        padding: 4px 4px calc(4px + env(safe-area-inset-bottom, 0px));
        border-top: 1px solid var(--border);
    }
    .sidebar-top, .sidebar-bottom {
        flex-direction: row;
        flex: 1;
        justify-content: space-around;
        gap: 0;
    }
    .nav-btn {
        flex-direction: column;
        align-items: center;
        gap: 2px;
        padding: 6px 6px;
        font-size: 10.5px;
        border-radius: var(--radius-sm);
    }
    .nav-btn .icon { width: auto; font-size: 19px; }
    .nav-label { display: block; }
    .nav-btn.active { font-weight: 500; }

    .main { flex: 1; min-height: 0; }
    .topbar { padding: 12px 16px 8px; }
    .topbar-title { font-size: 16px; }

    /* 对话流与输入区 */
    .chat-column { padding: 14px 12px 8px; }
    .empty-state { padding: 36px 16px; }
    .empty-state h2 { font-size: 21px; }
    .composer-wrap { padding: 4px 10px 8px; }
    .composer { padding: 10px 12px 8px; border-radius: 20px; }
    /* 16px 以上可避免 iOS 聚焦时自动放大 */
    .composer-input { font-size: 16px; }
    .ref-strip { margin-bottom: 8px; }
    .ref-item { width: 60px; height: 60px; }
    .composer-tools { gap: 6px; }
    .tools-left { gap: 4px; }
    .tool-select { font-size: 12px; padding: 6px 22px 6px 10px; }
    .icon-btn { width: 34px; height: 34px; }
    .send-btn { width: 40px; height: 40px; }
    .composer-hint { font-size: 10.5px; margin-top: 6px; }

    /* 结果网格：手机两列，竖版图也不至于太小 */
    .generated-images { grid-template-columns: repeat(2, 1fr); gap: 8px; }
    .gallery-grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }
    .page-column { padding: 16px 12px; }
    .page-title { font-size: 18px; margin-bottom: 12px; }

    /* 高级面板：双列紧凑排布 */
    .advanced-grid { grid-template-columns: 1fr 1fr; gap: 10px; }
    .advanced-panel { padding: 12px; }

    /* 模态框 → 底部抽屉式 */
    .modal { padding: 0; align-items: flex-end; }
    .modal-card {
        max-width: 100%;
        border-radius: 18px 18px 0 0;
        max-height: 92vh;
        max-height: 92dvh;
        padding-bottom: env(safe-area-inset-bottom, 0px);
    }
    .detail-layout { flex-direction: column; gap: 14px; }
    .detail-image { min-width: 0; }
    .detail-actions .chip-btn { flex: 1; justify-content: center; }

    /* 触屏设备没有 hover：图片操作按钮常显 */
    .image-card-overlay { opacity: 1; }
    .overlay-btn { width: 38px; height: 38px; font-size: 15px; }

    .notification {
        width: max-content;
        max-width: calc(100vw - 32px);
        text-align: center;
    }
}

@media (max-width: 400px) {
    .advanced-grid { grid-template-columns: 1fr; }
    .tools-left { width: 100%; }
    .tool-select { flex: 1 1 auto; }
    .tools-right { width: 100%; justify-content: space-between; }
}