:root {
    --color-bg: #f5f5f7;
    --color-surface: #ffffff;
    --color-border: #e5e7eb;
    --color-text: #1d1d1f;
    --color-text-secondary: #86868b;
    --color-primary: #0071e3;
    --color-primary-hover: #0077ed;
    --color-success: #34c759;
    --color-warn: #ff9f0a;
    --color-error: #ff3b30;
    --radius: 12px;
    --radius-sm: 8px;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
    --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-lg: 0 4px 16px rgba(0,0,0,0.08);
    --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Noto Sans SC", sans-serif;
}

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

body {
    font-family: var(--font);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
}

/* ----- Header ----- */
.toolbar {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    padding: 32px 24px 0;
}
.logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 28px;
    font-weight: 700;
    letter-spacing: 0;
    line-height: 1;
}
.logo-icon {
    width: 36px;
    height: 36px;
    display: block;
    flex: 0 0 auto;
    border-radius: 8px;
}
.tagline {
    font-size: 14px;
    color: var(--color-text-secondary);
}

/* ----- Main ----- */
main {
    flex: 1;
    max-width: 680px;
    width: 100%;
    margin: 0 auto;
    padding: 24px 16px 48px;
}

/* ----- Intro ----- */
.intro {
    text-align: center;
    padding: 20px 0 32px;
}
.intro-title {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 8px;
    letter-spacing: 1px;
}
.intro-desc {
    font-size: 15px;
    color: var(--color-text-secondary);
    margin-bottom: 24px;
    line-height: 1.5;
}

/* Format badges */
.format-badges {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-bottom: 28px;
    flex-wrap: wrap;
}
.badge {
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
    color: white;
}
.badge-pdf { background: #e74c3c; }
.badge-md   { background: #3498db; }
.badge-docx { background: #2e86de; }
.badge-img  { background: #10ac84; }
.badge-arrow {
    font-size: 18px;
    color: var(--color-text-secondary);
    font-weight: 300;
}

/* Feature grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
}
.feature-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    padding: 12px 8px;
    background: var(--color-surface);
    border-radius: var(--radius-sm);
    font-size: 12px;
    color: var(--color-text-secondary);
    box-shadow: var(--shadow-sm);
}
.feature-icon { font-size: 20px; }

/* ----- Upload ----- */
.upload-section {
    margin-bottom: 16px;
}
.drop-zone {
    border: 2px dashed #c9cdd4;
    border-radius: var(--radius);
    padding: 40px 24px;
    text-align: center;
    cursor: pointer;
    transition: border-color 0.2s, background 0.2s, box-shadow 0.2s;
    background: var(--color-surface);
    box-shadow: var(--shadow);
}
.drop-zone:hover {
    border-color: var(--color-primary);
    background: #f0f7ff;
    box-shadow: var(--shadow-lg);
}
.drop-zone.drag-over {
    border-color: var(--color-primary);
    background: #e8f2ff;
    box-shadow: var(--shadow-lg);
}
.drop-icon { color: var(--color-text-secondary); margin-bottom: 8px; }
.drop-text { font-size: 15px; font-weight: 500; margin-bottom: 4px; }
.drop-hint { font-size: 13px; color: var(--color-text-secondary); }

/* ----- File list ----- */
.file-list {
    display: none;
    background: var(--color-surface);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    margin-bottom: 16px;
}
.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 12px;
}
.file-list h2, .convert-settings h2, .job-list h2 {
    font-size: 16px;
    font-weight: 600;
}
.file-count { font-size: 13px; color: var(--color-text-secondary); }

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 12px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    margin-bottom: 8px;
    transition: box-shadow 0.15s;
}
.file-item:hover { box-shadow: var(--shadow-sm); }
.file-item .file-info { flex: 1; min-width: 0; }
.file-item .file-name {
    font-weight: 500;
    font-size: 14px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.file-item .file-meta { font-size: 12px; color: var(--color-text-secondary); margin-top: 2px; }
.file-item .file-remove {
    flex-shrink: 0;
    margin-left: 12px;
    padding: 4px 12px;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    background: var(--color-surface);
    color: var(--color-text-secondary);
    cursor: pointer;
    font-size: 13px;
    transition: all 0.15s;
}
.file-item .file-remove:hover {
    color: var(--color-error);
    border-color: var(--color-error);
    background: #fff5f5;
}

/* ----- Convert settings ----- */
.convert-settings {
    display: none;
    background: var(--color-surface);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    margin-bottom: 16px;
}
.settings-body { margin-top: 12px; }

.format-options {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
}
.fmt-btn {
    padding: 8px 20px;
    border: 2px solid var(--color-border);
    border-radius: 20px;
    background: var(--color-surface);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.15s;
    color: var(--color-text);
}
.fmt-btn:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}
.fmt-btn.selected {
    border-color: var(--color-primary);
    background: var(--color-primary);
    color: white;
}

.settings-extras {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
    font-size: 14px;
}
.ocr-label { cursor: pointer; display: flex; align-items: center; gap: 6px; }
.settings-extras select {
    padding: 6px 10px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 13px;
    background: var(--color-surface);
}

.settings-actions {
    display: flex;
    gap: 8px;
}

/* ----- Buttons ----- */
.btn-primary {
    padding: 10px 28px;
    background: var(--color-primary);
    color: white;
    border: none;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.15s, opacity 0.15s;
    letter-spacing: 0.3px;
}
.btn-primary:hover { background: var(--color-primary-hover); }
.btn-primary:disabled { opacity: 0.4; cursor: not-allowed; }

.btn-secondary {
    padding: 10px 24px;
    background: var(--color-surface);
    color: var(--color-text);
    border: 1px solid var(--color-border);
    border-radius: 20px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.15s;
}
.btn-secondary:hover { background: var(--color-bg); border-color: #c9cdd4; }

/* ----- Job list ----- */
.job-list {
    display: none;
    background: var(--color-surface);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    margin-bottom: 16px;
}
.job-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 12px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    margin-bottom: 8px;
    font-size: 14px;
}
.job-name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.job-arrow { color: var(--color-text-secondary); flex-shrink: 0; }
.job-target { font-weight: 500; flex-shrink: 0; }
.job-status {
    font-size: 12px;
    padding: 3px 10px;
    border-radius: 12px;
    font-weight: 500;
    flex-shrink: 0;
}
.job-status.pending   { background: #f5f5f7; color: var(--color-text-secondary); }
.job-status.running   { background: #e8f2ff; color: var(--color-primary); }
.job-status.succeeded { background: #e8f8ed; color: var(--color-success); }
.job-status.failed    { background: #fff0ef; color: var(--color-error); }

/* ----- Footer ----- */
.site-footer {
    text-align: center;
    padding: 24px 16px;
    font-size: 12px;
}
.site-footer a {
    color: var(--color-text-secondary);
    text-decoration: none;
}
.site-footer a:hover {
    color: var(--color-primary);
}

/* ----- Responsive ----- */
@media (max-width: 640px) {
    .toolbar { gap: 10px; padding-top: 24px; }
    .logo { font-size: 24px; }
    .logo-icon { width: 32px; height: 32px; }
    .tagline { font-size: 13px; }
    .intro-title { font-size: 18px; }
    .feature-grid { grid-template-columns: repeat(2, 1fr); }
    .format-badges { gap: 4px; }
    .badge { padding: 6px 14px; font-size: 12px; }
}