:root {
    --bg-main: #F3F4F6;
    --bg-surface: #FFFFFF;
    --accent: #C22026;
    --accent-hover: #AB1C21;
    --text-main: #1A1A1A;
    --text-muted: #6B7280;
    --border: #E5E7EB;
    --shadow: 0 10px 25px rgba(0,0,0,0.05);
    
    --top-h: 60px;
    --radius: 8px;
}

.hidden { display: none !important; }

.hint-text { 
    font-size: 11px; 
    color: var(--text-muted); 
    margin-top: 10px; 
    line-height: 1.4; 
    padding: 10px; 
    background: rgba(239, 239, 239, 0.5); 
    border-radius: 4px; 
    border-left: 3px solid var(--accent);
}

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

body {
    font-family: 'Montserrat', sans-serif;
    color: var(--text-main);
    background: var(--bg-main);
    overflow: hidden;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Top Navigation */
.top-nav {
    height: var(--top-h);
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    z-index: 100;
}

.logo-area {
    display: flex;
    align-items: center;
}
.logo-img { max-height: 40px; width: auto; display: block; object-fit: contain; }

.step-indicator {
    display: flex;
    align-items: center;
    gap: 12px;
}
.step {
    font-size: 13px;
    font-weight: 700;
    color: var(--text-muted);
    padding: 6px 12px;
    border-radius: 20px;
    transition: all 0.3s;
}
.step.active { background: var(--text-main); color: white; }
.step.done { color: var(--text-main); }
.step-line { width: 20px; height: 2px; background: var(--border); }

.nav-controls {
    display: flex;
    gap: 12px;
}

/* 按钮统一样式，提取公共类名 */
button {
    font-family: inherit;
    cursor: pointer;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 13px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    transition: all 0.2s;
}
button i { width: 16px; height: 16px; }

.btn-outline {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    color: var(--text-main);
    padding: 8px 16px;
}
.btn-outline:hover { background: var(--bg-main); }

.btn-primary {
    background: var(--accent);
    border: 1px solid var(--accent);
    color: white;
    padding: 8px 24px;
}
.btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }

/* Layout Main Area */
.wizard-layout {
    flex: 1;
    position: relative;
    display: flex;
}

.full-canvas {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: radial-gradient(circle at center, #F9FAFB 0%, #E5E7EB 100%);
    cursor: grab;
}
.full-canvas:active { cursor: grabbing; }

/* Panels */
.wizard-panel {
    position: absolute;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    border-radius: var(--radius);
    z-index: 50;
    transition: all 0.4s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.wizard-panel.hidden {
    opacity: 0;
    pointer-events: none;
    transform: translateY(20px);
}

.wizard-panel h3 {
    font-size: 12px;
    text-transform: uppercase;
    color: var(--text-muted);
    letter-spacing: 1px;
    margin-bottom: 20px;
}

/* Step 1 center panel - Grand Entrance Redesign */
.center-screen {
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    padding: 48px;
    width: 750px;
}
.center-screen.hidden { transform: translate(-50%, -45%); opacity: 0; }

.center-screen h3 {
    font-size: 16px;
    font-weight: 800;
    text-align: center;
    letter-spacing: 3px;
    margin-bottom: 40px;
}

.shape-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.shape-btn {
    flex-direction: column;
    background: linear-gradient(135deg, rgba(255,255,255,0.9), rgba(255,255,255,0.7));
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    padding: 40px 0;
    color: var(--text-muted);
    border-radius: 12px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.02);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    overflow: hidden;
}
.shape-btn svg { 
    width: 100px; 
    height: 100px; 
    margin-bottom: 12px; 
    transform: rotate(-45deg) scale(0.9);
    filter: drop-shadow(3px 4px 0 rgba(0,0,0,0.35));
    transition: all 0.4s ease; 
}
.shape-btn svg polygon:not(.grid-overlay),
.shape-btn svg rect:not(.grid-overlay) {
    fill: #e8e8e8;
    stroke: #555;
    stroke-width: 1.2;
    stroke-linejoin: round;
    transition: fill 0.3s ease;
}
.shape-btn svg .grid-overlay {
    fill: url(#tile-grid);
    stroke: none;
    pointer-events: none;
}
.shape-btn:hover, .shape-btn.active {
    border-color: var(--accent);
    color: var(--text-main);
    transform: translateY(-8px) scale(1.05);
    background: white;
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.15);
}
.shape-btn:hover svg { 
    transform: rotate(-45deg) scale(1.0);
    filter: drop-shadow(4px 5px 0 rgba(194,32,38,0.3));
}
.shape-btn:hover svg polygon:not(.grid-overlay),
.shape-btn:hover svg rect:not(.grid-overlay) {
    fill: #f0f0f0;
    stroke: var(--accent);
}
.shape-btn:active {
    transform: translateY(2px) scale(0.98);
}
.shape-btn span { font-size: 15px; font-weight: 700; }

.panel-hint {
    margin-top: 32px;
    font-size: 13px;
    text-align: center;
    color: var(--text-muted);
    font-weight: 500;
}

/* Toast */
.toast {
    position: absolute;
    top: 24px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(26,26,26,0.85);
    color: white;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    z-index: 40;
    pointer-events: none;
    transition: opacity 0.3s;
}
.toast.hidden { opacity: 0; }

/* Step 3 Sidebar */
.right-sidebar {
    top: 20px;
    right: 20px;
    bottom: 20px;
    width: 380px;
    padding: 0;
    overflow: visible;
    transition: all 0.5s cubic-bezier(0.2, 0.8, 0.2, 1);
}
.sidebar-content {
    height: 100%;
    overflow-y: auto;
    padding: 24px;
}
.right-sidebar.hidden { transform: translateX(calc(100% + 40px)); opacity: 0; }
.right-sidebar.collapsed { transform: translateX(calc(100% - 30px)); padding-left: 50px; }

.sidebar-toggle {
    position: absolute;
    left: -24px;
    top: 50%;
    transform: translateY(-50%);
    width: 24px;
    height: 80px;
    background: var(--accent);
    border: none;
    border-radius: 12px 0 0 12px;
    box-shadow: -4px 0 15px rgba(194,32,38,0.2);
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}
.sidebar-toggle:hover { 
    width: 32px; 
    left: -32px;
    background: var(--accent-hover);
}
.sidebar-toggle i { width: 18px; height: 18px; transition: transform 0.4s; }

.right-sidebar.collapsed .sidebar-toggle i,
.right-sidebar.collapsed .sidebar-toggle svg { 
    transform: rotate(180deg); 
}
.right-sidebar.collapsed .sidebar-toggle { left: 4px; border-radius: 0 12px 12px 0; }
.sidebar-toggle i,
.sidebar-toggle svg { 
    display: flex; 
    align-items: center; 
    justify-content: center; 
    width: 18px; 
    height: 18px; 
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1); 
}

.config-section {
    margin-bottom: 24px;
}
.config-section label {
    display: block;
    font-size: 12px;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text-main);
}
.config-section.row-flex {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.config-section.row-flex label { margin-bottom: 0; }

.toggle-group { display: flex; background: var(--bg-main); border-radius: var(--radius); padding: 4px; }
.toggle-btn {
    flex: 1; padding: 8px; border: none; background: none; font-size: 11px; border-radius: 4px; color: var(--text-muted);
    white-space: nowrap;
}
.toggle-btn.active { background: var(--bg-surface); color: var(--accent); box-shadow: 0 1px 3px rgba(0,0,0,0.1); }

.styled-select {
    width: 100%; padding: 10px; background: var(--bg-main); border: 1px solid var(--border);
    border-radius: var(--radius); font-family: inherit; font-size: 13px; font-weight: 600; outline: none;
}

.color-palette {
    display: grid; grid-template-columns: repeat(5, 1fr); gap: 6px; margin-top: 8px;
}

.swatch {
    aspect-ratio: 1; border-radius: 2px; cursor: pointer; transition: all 0.15s;
    border: 2px solid #E5E7EB; position: relative; overflow: hidden;
}

/* Simulate the ribbed texture overlay similar to the screenshot */
.swatch::after {
    content: ''; position: absolute; inset: 0;
    background: repeating-linear-gradient(45deg, rgba(255,255,255,0.2) 0, rgba(255,255,255,0.2) 2px, transparent 2px, transparent 6px),
                repeating-linear-gradient(-45deg, rgba(0,0,0,0.05) 0, rgba(0,0,0,0.05) 2px, transparent 2px, transparent 6px);
}

.swatch.active { border-color: var(--accent); z-index: 1; box-shadow: inset 0 0 0 1px var(--bg-surface); }
.swatch:hover { border-color: var(--text-muted); z-index: 1; transform: scale(1.05); }

/* Edging Palettes - Elongated */
.swatch-edging { aspect-ratio: auto; height: 18px; border-radius: 4px; }

/* Switch Toggle */
.switch { position: relative; display: inline-block; width: 44px; height: 24px; }
.switch input { opacity: 0; width: 0; height: 0; }
.slider { position: absolute; cursor: pointer; top: 0; left: 0; right: 0; bottom: 0; background-color: #ccc; transition: .4s; }
.slider:before { position: absolute; content: ""; height: 16px; width: 16px; left: 4px; bottom: 4px; background-color: white; transition: .4s; }
input:checked + .slider { background-color: var(--accent); }
input:checked + .slider:before { transform: translateX(20px); }
.slider.round { border-radius: 24px; }
.slider.round:before { border-radius: 50%; }

/* Step 4 Result */
.result-modal {
    top: 50%; left: 50%; transform: translate(-50%, -50%);
    width: 680px; max-height: 85vh; overflow-y: auto; padding: 36px 40px;
}
.result-modal.hidden { transform: translate(-50%, -40%); opacity: 0; }

.result-stats {
    display: flex; gap: 16px; margin-bottom: 24px;
}
.stat-box {
    flex: 1; background: var(--bg-main); padding: 16px; border-radius: var(--radius); text-align: center;
}
.stat-lbl { display: block; font-size: 10px; font-weight: 700; color: var(--text-muted); margin-bottom: 6px; }
.stat-box strong { font-size: 24px; color: var(--accent); }

.manifest-table { width: 100%; border-collapse: collapse; font-size: 12px; }
.manifest-table th { background: var(--bg-main); padding: 8px; text-align: left; }
.manifest-table td { padding: 8px; border-bottom: 1px solid var(--border); }

.close-btn { position: absolute; top: 16px; right: 16px; background: none; border: none; padding: 4px; color: var(--text-muted); cursor: pointer; }
.close-btn:hover { color: var(--text-main); }
.full-w { width: 100%; }
.mt-20 { margin-top: 20px; }

/* Export Button Group */
.export-btn-group {
    display: flex;
    gap: 8px;
    margin-top: 20px;
}
.btn-export {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-surface);
    color: var(--text-main);
    transition: all 0.2s;
    text-align: left;
}
.btn-export i { width: 20px; height: 20px; flex-shrink: 0; }
.btn-export div { display: flex; flex-direction: column; gap: 2px; }
.btn-export strong { font-size: 11px; font-weight: 700; }
.btn-export small { font-size: 9px; color: var(--text-muted); font-weight: 400; }
.btn-export:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0,0,0,0.1); }

.btn-export-pdf { border-color: var(--accent); background: var(--accent); color: white; }
.btn-export-pdf small { color: rgba(255,255,255,0.7); }
.btn-export-pdf:hover { background: var(--accent-hover); }

.btn-export-png:hover { border-color: #3b82f6; color: #3b82f6; }
.btn-export-csv:hover { border-color: #10b981; color: #10b981; }

/* Tool Exclusivity */
.locked-ui { 
    opacity: 0.5; 
    pointer-events: none; 
    filter: grayscale(0.5);
    cursor: not-allowed;
}

/* ========================================
   RESPONSIVE: Tablet (≤1024px)
   ======================================== */
@media (max-width: 1024px) {
    .top-nav {
        padding: 0 16px;
    }

    .step-indicator {
        gap: 6px;
    }
    .step {
        font-size: 11px;
        padding: 5px 8px;
    }
    .step-line {
        width: 12px;
    }

    /* Step 1: Narrower panel, 3 columns */
    .center-screen {
        width: 90vw;
        max-width: 800px;
        padding: 40px;
    }
    .shape-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 16px;
    }
    .shape-btn {
        padding: 28px 0;
    }
    .shape-btn svg {
        width: 56px;
        height: 56px;
        margin-bottom: 14px;
    }

    /* Step 3: Narrower sidebar */
    .right-sidebar {
        width: 320px;
        top: 12px;
        right: 12px;
        bottom: 12px;
    }

    /* Step 4: Responsive modal */
    .result-modal {
        width: 90vw;
        max-width: 680px;
        padding: 28px 24px;
    }
}

/* ========================================
   RESPONSIVE: Mobile landscape / small tablet (≤768px)
   ======================================== */
@media (max-width: 768px) {
    :root {
        --top-h: 52px;
    }

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

    .logo-img {
        max-height: 30px;
    }

    /* Hide step indicator on mobile to free up space for nav buttons */
    .step-indicator {
        display: none;
    }

    /* Nav buttons compact */
    .btn-outline, .btn-primary {
        padding: 6px 12px;
        font-size: 12px;
    }
    .nav-controls {
        gap: 8px;
    }

    /* Step 1: Fills screen, 2 columns */
    .center-screen {
        width: 94vw;
        max-width: none;
        padding: 24px 20px;
        max-height: 80vh;
        overflow-y: auto;
    }
    .center-screen h3 {
        font-size: 13px;
        letter-spacing: 2px;
        margin-bottom: 20px;
    }
    .shape-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }
    .shape-btn {
        padding: 20px 0;
        border-radius: 8px;
    }
    .shape-btn svg {
        width: 48px;
        height: 48px;
        margin-bottom: 10px;
    }
    .shape-btn:hover {
        transform: none;
        box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    }
    .shape-btn:hover svg {
        transform: rotate(-45deg) scale(0.9);
    }
    .panel-hint {
        margin-top: 16px;
        font-size: 12px;
    }

    /* Step 3: Bottom sheet instead of right sidebar */
    .right-sidebar {
        top: auto;
        right: 0;
        bottom: 0;
        left: 0;
        width: 100%;
        height: 55vh;
        max-height: 55vh;
        border-radius: 16px 16px 0 0;
        border-bottom: none;
        box-shadow: 0 -8px 30px rgba(0,0,0,0.15);
    }
    .right-sidebar.hidden {
        transform: translateY(100%);
        opacity: 0;
    }
    .right-sidebar.collapsed {
        transform: translateY(calc(100% - 48px));
        padding-left: 0;
    }
    .sidebar-content {
        padding: 20px 20px 40px;
    }

    /* Sidebar toggle repositioned as top handle */
    .sidebar-toggle {
        position: absolute;
        left: 50%;
        top: -20px;
        transform: translateX(-50%);
        width: 80px;
        height: 20px;
        border-radius: 12px 12px 0 0;
        box-shadow: 0 -4px 10px rgba(194,32,38,0.15);
    }
    .sidebar-toggle:hover {
        width: 80px;
        left: 50%;
        transform: translateX(-50%);
        top: -24px;
        height: 24px;
    }
    .sidebar-toggle i,
    .sidebar-toggle svg {
        transform: rotate(-90deg);
    }
    .right-sidebar.collapsed .sidebar-toggle {
        left: 50%;
        transform: translateX(-50%);
        border-radius: 12px 12px 0 0;
    }
    .right-sidebar.collapsed .sidebar-toggle i,
    .right-sidebar.collapsed .sidebar-toggle svg {
        transform: rotate(90deg);
    }

    /* Color palette: more columns on wider mobiles */
    .color-palette {
        grid-template-columns: repeat(6, 1fr);
    }

    /* Step 4: Full width modal */
    .result-modal {
        width: 96vw;
        max-height: 80vh;
        padding: 24px 20px;
    }

    /* Export buttons stack */
    .export-btn-group {
        flex-direction: column;
    }
    .btn-export {
        padding: 12px;
    }

    /* Toast repositioned */
    .toast {
        top: 12px;
        font-size: 11px;
        padding: 6px 14px;
        max-width: 90vw;
        text-align: center;
    }

    /* Larger touch targets for switches */
    .switch {
        width: 48px;
        height: 26px;
    }
    .slider:before {
        height: 18px;
        width: 18px;
    }
}

/* ========================================
   RESPONSIVE: Small phones (≤480px)
   ======================================== */
@media (max-width: 480px) {
    :root {
        --top-h: 48px;
    }

    .top-nav {
        padding: 0 8px;
    }

    .logo-img {
        max-height: 24px;
    }

    /* Abbreviate steps further */
    .step {
        font-size: 9px;
        padding: 3px 6px;
        letter-spacing: 0;
    }
    .step-line {
        width: 4px;
    }

    .btn-outline, .btn-primary {
        padding: 5px 10px;
        font-size: 11px;
    }
    /* Hide text labels on buttons, keep icons */
    .btn-outline {
        padding: 6px;
    }

    /* Step 1: Single column on very small screens */
    .center-screen {
        padding: 20px 16px;
        width: 100vw;
        border-radius: 0;
        border: none;
        max-height: 85vh;
    }
    .center-screen h3 {
        font-size: 12px;
        margin-bottom: 16px;
    }
    .shape-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 8px;
    }
    .shape-btn {
        padding: 16px 0;
        font-size: 11px;
    }
    .shape-btn svg {
        width: 40px;
        height: 40px;
        margin-bottom: 6px;
    }

    /* Step 3: Taller bottom sheet */
    .right-sidebar {
        height: 60vh;
        max-height: 60vh;
    }
    .sidebar-content {
        padding: 16px 16px 48px;
    }

    .config-section {
        margin-bottom: 16px;
    }
    .config-section label {
        font-size: 11px;
        margin-bottom: 6px;
    }
    .toggle-btn {
        font-size: 10px;
        padding: 6px 4px;
    }
    .styled-select {
        font-size: 12px;
        padding: 8px;
    }
    .color-palette {
        grid-template-columns: repeat(5, 1fr);
        gap: 4px;
    }

    .hint-text {
        font-size: 10px;
        padding: 8px;
    }

    /* Step 4: Full screen modal */
    .result-modal {
        width: 100vw;
        max-height: 90vh;
        border-radius: 12px 12px 0 0;
        padding: 20px 16px;
    }
    .manifest-table {
        font-size: 11px;
    }
    .manifest-table th, .manifest-table td {
        padding: 6px 4px;
    }

    .export-btn-group {
        gap: 6px;
    }
    .btn-export strong {
        font-size: 10px;
    }
    .btn-export small {
        font-size: 8px;
    }
}