:root {
    --primary: #1f8abe;
    --primary-dark: #1870a0;
    --primary-light: #40a8d8;
    --bg: #f5f7fc;
    --card-bg: #ffffff;
    --text: #1e2a3e;
    --text-secondary: #6b7f8a;
    --border: #e8edf2;
    --danger: #e74c3c;
    --warning: #f39c12;
    --success: #27ae60;
    --radius: 12px;
    --radius-lg: 16px;
    --shadow: 0 2px 8px rgba(0,0,0,0.06);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.10);
    --sidebar-width: 260px;
    --nav-height: 56px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    overflow: hidden;
    height: 100vh;
}

/* Nav */
.tools-nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: var(--nav-height);
    z-index: 100;
    background: rgba(255,255,255,0.90);
    backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid var(--border);
}

.tools-nav-inner {
    max-width: 100%;
    margin: 0 auto;
    padding: 0 20px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
}

.tools-nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--primary);
    margin-right: auto;
}

.tools-nav-brand i { font-size: 1.2rem; }

.tools-nav-right { display: flex; align-items: center; gap: 10px; }

.nav-btn {
    display: flex;
    align-items: center;
    gap: 5px;
    padding: 7px 14px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: transparent;
    color: var(--text-secondary);
    font-size: 0.83rem;
    font-family: inherit;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

.nav-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(31,138,190,0.05);
}

.nav-btn.admin-btn:hover {
    border-color: var(--warning);
    color: var(--warning);
    background: rgba(243,156,18,0.06);
}

/* Main Layout */
.main-content {
    padding-top: var(--nav-height);
    height: 100vh;
}

.dashboard {
    display: flex;
    height: calc(100vh - var(--nav-height));
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: var(--card-bg);
    border-right: 1px solid var(--border);
    overflow-y: auto;
    flex-shrink: 0;
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.sidebar-backdrop { display: none; }

.mobile-sidebar-edge-toggle { display: none; }

.sidebar-header {
    padding: 20px 16px 12px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.sidebar-header h3 {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.sidebar-header h3 i { margin-right: 6px; }

.tool-list { padding: 8px; }

.tool-item {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 10px 14px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.15s;
    margin-bottom: 2px;
    color: var(--text);
    border: 1px solid transparent;
}

.tool-item:hover { background: rgba(31,138,190,0.05); }

.tool-item.active {
    background: rgba(31,138,190,0.08);
    border-right: 3px solid var(--primary);
}

.tool-item.active .tool-item-name {
    color: var(--primary);
}

.tool-item-name {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.tool-item-desc {
    font-size: 0.72rem;
    color: #999;
    margin-top: 3px;
    display: flex;
    align-items: center;
    gap: 4px;
    font-weight: 400;
}

.tool-item.active .tool-item-desc { color: #999; }

.tool-item-desc i { font-size: 0.65rem; color: #aaa; }

/* Content Area */
.content-area {
    flex: 1;
    overflow-y: auto;
    padding: 24px;
}

.no-tool {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 60%;
    color: var(--text-secondary);
}

.no-tool i { font-size: 3rem; margin-bottom: 16px; opacity: 0.4; }

.no-tool p { font-size: 1rem; }

/* Tool Detail */
.tool-detail { width: 100%; }

.encoding-converter-tool {
    max-width: 1000px;
}

.wsl-usb-columns {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-start;
    gap: 20px;
}

.wsl-usb-main,
.wsl-usb-side {
    flex: 0 0 800px;
    width: 800px;
}

.lvgl-font-columns {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-start;
    gap: 20px;
}

.lvgl-font-main,
.lvgl-font-side {
    flex: 0 0 800px;
    width: 800px;
}

.lvgl-img-columns {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-start;
    gap: 20px;
}

.lvgl-img-main,
.lvgl-img-side {
    flex: 0 0 800px;
    width: 800px;
}

.color-palette-columns {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-start;
    gap: 20px;
}

.color-palette-main,
.color-palette-side {
    flex: 0 0 800px;
    width: 800px;
}

.tool-header {
    margin-bottom: 20px;
}

.tool-header h2 {
    font-size: 1.2rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 8px;
}

.tool-header h2 i { color: var(--primary); }

.tool-header p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 4px;
}

/* 卡片化表单控件 */
.form-card {
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 12px;
    background: #fafbfc;
}
.form-card .form-card-label {
    display: block;
    font-size: 0.82rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
    font-weight: 500;
}
.form-card .form-card-control,
.form-card select,
.form-card textarea,
.form-card input[type="text"] {
    width: 100%;
    padding: 6px 10px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.9rem;
    font-family: inherit;
    background: #fff;
    outline: none;
    box-sizing: border-box;
    color: var(--text);
}

.form-card textarea {
    resize: vertical;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.85rem;
}
.form-card select:focus,
.form-card textarea:focus,
.form-card input:focus {
    border-color: var(--primary);
}

.form-card-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}
.form-card-grid .form-card.grid-full {
    grid-column: 1 / -1;
}

/* Converter Card */
.converter-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    margin-bottom: 16px;
    box-shadow: var(--shadow);
}

.converter-card h3 {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.3px;
    margin-bottom: 16px;
}

.converter-card h3 i { margin-right: 6px; color: var(--primary); }

.form-row {
    display: flex;
    gap: 12px;
    align-items: flex-end;
}

.form-row .form-group { flex: 1; }

.convert-actions {
    display: flex;
    gap: 10px;
    margin-top: 16px;
}

.convert-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    border-radius: var(--radius);
    font-size: 0.95rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
}

.convert-btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    box-shadow: 0 4px 14px rgba(31,138,190,0.30);
}

.convert-btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(31,138,190,0.35);
}

.convert-btn-sm {
    padding: 8px 20px;
    font-size: 0.85rem;
    background: rgba(31,138,190,0.12);
    color: var(--primary);
    box-shadow: none;
}

.convert-btn-sm:hover {
    background: rgba(31,138,190,0.18);
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(31,138,190,0.15);
}

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

.convert-btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(31,138,190,0.04);
}

.convert-result {
    margin-top: 16px;
    padding: 12px;
    background: #f8fafc;
    border-radius: 8px;
    border: 1px solid var(--border);
}

.convert-result .result-line {
    font-size: 0.85rem;
    line-height: 1.6;
    color: var(--text-secondary);
}

.convert-result .result-line code {
    background: rgba(31,138,190,0.08);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.83rem;
    color: var(--primary);
}

.convert-result .result-line.success {
    color: var(--success);
    font-weight: 500;
}

/* Feature Grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 10px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.88rem;
    color: var(--text);
    padding: 8px 12px;
    background: #f8fafc;
    border-radius: 8px;
    border: 1px solid var(--border);
}

.feature-item i {
    color: var(--success);
    font-size: 0.8rem;
    flex-shrink: 0;
}

.version-badge {
    display: inline-block;
    background: var(--primary);
    color: #fff;
    font-size: 0.72rem;
    font-weight: 600;
    padding: 2px 10px;
    border-radius: 10px;
    margin-left: 6px;
    vertical-align: middle;
}

/* Toast */
.toast {
    position: fixed;
    top: 70px;
    right: 20px;
    z-index: 2000;
    padding: 12px 20px;
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 500;
    color: white;
    opacity: 0;
    transform: translateY(-10px);
    transition: all 0.3s ease;
    pointer-events: none;
}

.toast.show { opacity: 1; transform: translateY(0); }

.toast.success { background: var(--success); box-shadow: 0 4px 16px rgba(39,174,96,0.30); }

.toast.error { background: var(--danger); box-shadow: 0 4px 16px rgba(231,76,60,0.30); }

.toast.info { background: var(--primary); box-shadow: 0 4px 16px rgba(31,138,190,0.30); }

/* Install Steps */
.install-steps {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.install-step {
    display: flex;
    gap: 14px;
    align-items: flex-start;
}

.step-num {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--primary);
    color: white;
    font-size: 0.82rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    margin-top: 1px;
}

.step-body {
    flex: 1;
    min-width: 0;
}

.step-title {
    font-size: 0.92rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 4px;
}

.step-desc {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.step-desc code {
    background: rgba(31,138,190,0.08);
    padding: 1px 6px;
    border-radius: 4px;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.83rem;
    color: var(--primary);
}

.step-cmd-row {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-top: 6px;
}

.step-cmd {
    display: inline-block;
    background: #0a1628;
    color: #a8d8ea;
    padding: 6px 14px;
    border-radius: 6px;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.83rem;
    word-break: break-all;
}

.copy-btn {
    width: 30px;
    height: 30px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--card-bg);
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.78rem;
    flex-shrink: 0;
    transition: all 0.15s;
}

.copy-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(31,138,190,0.05);
}

.step-code {
    background: #0a1628;
    color: #a8d8ea;
    padding: 12px 16px;
    border-radius: 8px;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.8rem;
    line-height: 1.6;
    margin-top: 8px;
    overflow-x: auto;
    white-space: pre;
}

.cmd-tags-row {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 4px;
}

.cmd-tag {
    display: inline-block;
    background: rgba(31,138,190,0.08);
    color: var(--primary);
    padding: 3px 10px;
    border-radius: 5px;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.8rem;
}

/* Changelog */
.changelog-box {
    background: #fafbfc;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 14px 18px;
    font-size: 0.85rem;
    line-height: 1.7;
}

.changelog-version {
    font-weight: 700;
    color: var(--primary);
    font-size: 0.9rem;
    margin-top: 12px;
    margin-bottom: 4px;
}

.changelog-version:first-child {
    margin-top: 0;
}

.changelog-item {
    padding-left: 14px;
    color: var(--text-secondary);
    font-size: 0.83rem;
}

.changelog-fix {
    color: var(--warning);
    font-size: 0.83rem;
    padding-left: 14px;
}

.changelog-text {
    color: var(--text-secondary);
    font-size: 0.83rem;
    padding-left: 14px;
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #d0d8e0; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #b0b8c0; }

/* Mobile */
@media (max-width: 768px) {
    body { overflow-x: hidden; }
    .dashboard { position: relative; }

    .tools-nav-inner { padding: 0 12px; gap: 8px; }

    .sidebar {
        position: absolute;
        top: 0; left: 0; bottom: 0;
        width: min(280px, 78vw);
        z-index: 30;
        transform: translateX(calc(-100% - 12px));
        box-shadow: none;
    }

    .mobile-sidebar-edge-toggle {
        position: absolute;
        top: 50%;
        left: -3px;
        z-index: 40;
        display: inline-flex;
        align-items: center;
        justify-content: center;
        width: 24px;
        height: 44px;
        padding: 0;
        border: none;
        background: transparent;
        color: rgba(30,42,62,0.55);
        font-size: 1rem;
        cursor: pointer;
        transform: translateY(-50%);
        transition: left 0.25s ease, color 0.2s ease;
        text-shadow: 0 1px 6px rgba(255,255,255,0.9);
    }

    .mobile-sidebar-edge-toggle::before {
        content: '';
        position: absolute;
        top: 50%; left: 50%;
        width: 48px; height: 48px;
        border-radius: 50%;
        background: radial-gradient(circle, rgba(246,180,40,0.8) 0%, rgba(246,180,40,0.38) 45%, rgba(246,180,40,0) 75%);
        box-shadow: 0 0 18px rgba(246,180,40,0.5);
        transform: translate(-50%, -50%) scale(0.6);
        opacity: 0;
        pointer-events: none;
    }

    body.mobile-sidebar-hint-active .mobile-sidebar-edge-toggle::before {
        animation: mobile-sidebar-halo 1.8s ease-out infinite;
    }
    body.mobile-sidebar-hint-active .mobile-sidebar-edge-toggle {
        animation: mobile-sidebar-arrow-pulse 1.8s ease-in-out infinite;
    }

    .mobile-sidebar-edge-toggle:hover { color: var(--primary); }

    body.mobile-sidebar-open .mobile-sidebar-edge-toggle {
        left: calc(min(280px, 78vw) - 3px);
        color: var(--primary);
    }
    body.mobile-sidebar-open .mobile-sidebar-edge-toggle i { transform: rotate(180deg); }

    @keyframes mobile-sidebar-halo {
        0% { opacity: 0.9; transform: translate(-50%, -50%) scale(0.7); }
        70% { opacity: 0; transform: translate(-50%, -50%) scale(2); }
        100% { opacity: 0; transform: translate(-50%, -50%) scale(2); }
    }
    @keyframes mobile-sidebar-arrow-pulse {
        0% { opacity: 0.55; text-shadow: 0 1px 6px rgba(255,255,255,0.55); }
        50% { opacity: 1; text-shadow: 0 1px 10px rgba(255,255,255,0.95); }
        100% { opacity: 0.55; text-shadow: 0 1px 6px rgba(255,255,255,0.55); }
    }

    body.mobile-sidebar-open .sidebar {
        transform: translateX(0);
        box-shadow: 0 12px 32px rgba(0,0,0,0.18);
    }

    .sidebar-backdrop {
        display: block;
        position: absolute;
        inset: 0;
        background: rgba(10,22,40,0.28);
        opacity: 0;
        pointer-events: none;
        transition: opacity 0.25s ease;
        z-index: 20;
    }
    body.mobile-sidebar-open .sidebar-backdrop {
        opacity: 1;
        pointer-events: auto;
    }

    .content-area { width: 100%; padding: 16px; }

    .form-row { flex-direction: column; gap: 0; }
    .cmd-tags-row { flex-direction: column; }

    /* 两列布局 → 单列 */
    .tool-flex-row { flex-direction: column !important; }
    .tool-flex-col { min-width: 0 !important; flex: none !important; width: 100% !important; }
    .lvgl-flex-row { flex-direction: column !important; }
    .lvgl-flex-col { min-width: 0 !important; flex: none !important; width: 100% !important; }
}