/* ─── Reset ─── */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-tap-highlight-color: transparent;
}

:root {
    --bg-0: #0c0c0e;
    --bg-1: #111113;
    --bg-2: #19191d;
    --bg-3: #242429;
    --border: #2a2a30;
    --border-hover: #3a3a42;
    --text-1: #e8e8ec;
    --text-2: #a0a0a8;
    --text-3: #686870;
    --accent: #6c8aff;
    --accent-dim: #1e2233;
    --danger: #ff4455;
    --success: #44cc88;
    --radius: 10px;
    --radius-sm: 7px;
    --font-mono: 'JetBrains Mono', monospace;
    --font-sans: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
    --tr: 0.18s ease;
    --panel-w: 360px;
}

body, html {
    height: 100dvh;
    background: var(--bg-0);
    color: var(--text-1);
    font-family: var(--font-sans);
    font-size: 13px;
    overflow: hidden;
    -webkit-font-smoothing: antialiased;
}

/* ═══════════════════════════════════
   APP LAYOUT — Mobile First
   ═══════════════════════════════════ */
#app {
    height: 100dvh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* ─── Canvas Area ───
   touch-action:none ONLY here so drawing works.
   The controls panel keeps default touch-action for scrolling. */
#canvas-area {
    flex: 1 1 0;
    min-height: 0;
    background: var(--bg-0);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    touch-action: none;          /* ← drawing surface: no browser gestures */
    cursor: crosshair;
}

#canvas-area.eraser-mode { cursor: none; }
#canvas-area.select-mode { cursor: default; }
#canvas-area.panning { cursor: grab; }
#canvas-area.panning:active { cursor: grabbing; }

#drawCanvas {
    display: block;
    border-radius: 2px;
    position: absolute;
    transform-origin: 0 0;
}

/* ─── Brush Cursor ─── */
#brushCursor {
    position: absolute;
    border: 1.5px solid rgba(108,138,255,0.6);
    border-radius: 50%;
    pointer-events: none;
    z-index: 10;
    display: none;
    transform: translate(-50%, -50%);
    transition: width 0.08s, height 0.08s;
}
#canvas-area:hover #brushCursor { display: block; }
#canvas-area.select-mode #brushCursor { display: none; }

#canvas-info {
    position: absolute;
    bottom: 8px;
    left: 50%;
    transform: translateX(-50%);
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--text-3);
    background: rgba(0,0,0,0.6);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    padding: 4px 12px;
    border-radius: 12px;
    display: flex;
    gap: 10px;
    pointer-events: none;
    white-space: nowrap;
    z-index: 5;
}

/* ─── Fullscreen View ─── */
#fullscreen-view {
    position: fixed;
    inset: 0;
    z-index: 9999;
    background: var(--bg-0);
    display: flex;
    align-items: center;
    justify-content: center;
}
#fullscreen-view.hidden { display: none; }
#fullscreenCanvas { max-width: 100%; max-height: 100%; object-fit: contain; }
.close-btn {
    position: absolute; top: 16px; right: 16px;
    width: 40px; height: 40px;
    background: rgba(0,0,0,0.6); border: 1px solid var(--border);
    color: var(--text-1); border-radius: 50%; cursor: pointer;
    display: grid; place-items: center; backdrop-filter: blur(6px);
}

/* ─── Controls Panel ───
   touch-action:auto so scrolling works on mobile! */
#controls {
    flex: 1 1 0;
    min-height: 0;
    overflow: hidden;
    background: var(--bg-1);
    display: flex;
    flex-direction: column;
    border-top: 1px solid var(--border);
    z-index: 100;
    touch-action: auto;          /* ← allow normal scroll/touch in controls */
}

.scroll-container {
    flex: 1 1 0;
    min-height: 0;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 10px;
    display: flex;
    flex-direction: column;
    gap: 6px;
    scrollbar-width: thin;
    scrollbar-color: var(--bg-3) transparent;
    -webkit-overflow-scrolling: touch;
    overscroll-behavior: contain;    /* prevent pull-to-refresh */
}

.scroll-container::-webkit-scrollbar { width: 4px; }
.scroll-container::-webkit-scrollbar-track { background: transparent; }
.scroll-container::-webkit-scrollbar-thumb { background: var(--bg-3); border-radius: 2px; }

/* ─── Quick Actions ─── */
.quick-actions {
    display: flex;
    gap: 6px;
    flex-shrink: 0;
}

.btn-action {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 5px;
    padding: 9px 10px;
    background: var(--bg-2);
    border: 1px solid var(--border);
    color: var(--text-2);
    font-family: var(--font-mono);
    font-size: 10px;
    font-weight: 700;
    letter-spacing: 0.5px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--tr);
    white-space: nowrap;
}

.btn-action:hover { color: var(--text-1); border-color: var(--border-hover); }
.btn-action:active { transform: scale(0.97); }
.btn-action.primary { background: var(--accent-dim); color: var(--accent); border-color: var(--accent); }
.btn-action.primary:hover { background: var(--accent); color: var(--bg-0); }
.btn-action.danger:hover { color: var(--danger); border-color: var(--danger); }

/* ─── Tool Bar ─── */
.tool-bar {
    display: flex;
    gap: 4px;
    padding: 6px;
    background: var(--bg-2);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    flex-shrink: 0;
}

.tool-btn {
    width: 36px; height: 32px;
    background: none;
    border: 1px solid transparent;
    color: var(--text-3);
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: grid; place-items: center;
    transition: all var(--tr);
    padding: 0;
}
.tool-btn:hover { color: var(--text-1); background: var(--bg-3); }
.tool-btn.active { color: var(--accent); border-color: var(--accent); background: var(--accent-dim); }

.tool-separator {
    width: 1px; background: var(--border);
    margin: 2px 4px; flex-shrink: 0;
}

/* ─── Tool Navigation ─── */
.tool-nav-link {
    display: flex; align-items: center; gap: 10px;
    padding: 10px 12px; background: var(--bg-2);
    border: 1px solid var(--border); border-radius: var(--radius);
    text-decoration: none; color: var(--text-1);
    transition: all var(--tr); flex-shrink: 0;
}
.tool-nav-link:hover { border-color: var(--accent); background: var(--accent-dim); }
.tool-nav-icon { font-size: 18px; flex-shrink: 0; }
.tool-nav-text { flex: 1; font-family: var(--font-mono); font-size: 10px; color: var(--text-2); line-height: 1.4; }
.tool-nav-text strong { color: var(--text-1); font-weight: 700; }
.tool-nav-arrow { font-family: var(--font-mono); font-size: 14px; color: var(--text-3); flex-shrink: 0; }

/* ─── Collapsible Sections ─── */
.section-collapsible {
    background: var(--bg-2); border: 1px solid var(--border);
    border-radius: var(--radius); flex-shrink: 0;
}
.section-collapsible[open] { border-color: var(--border-hover); }

.section-toggle {
    display: flex; align-items: center; padding: 9px 12px;
    cursor: pointer; user-select: none; list-style: none; gap: 8px;
}
.section-toggle::-webkit-details-marker { display: none; }
.section-toggle::marker { content: ''; }
.section-toggle h2 {
    font-family: var(--font-mono); font-size: 10px; font-weight: 700;
    letter-spacing: 1.5px; color: var(--text-2); flex: 1;
}
.section-toggle::before {
    content: '\25B8'; font-size: 9px; color: var(--text-3);
    transition: transform var(--tr); flex-shrink: 0;
}
.section-collapsible[open] > .section-toggle::before { transform: rotate(90deg); }

.section-body {
    padding: 0 12px 10px; display: flex;
    flex-direction: column; gap: 7px;
}

/* ─── Hint text ─── */
.hint-text {
    font-size: 11px; color: var(--text-3); line-height: 1.5;
}

/* ─── Form Fields ─── */
.field {
    display: flex; flex-direction: column; gap: 4px;
    flex: 1; min-width: 0;
}
.field label {
    font-family: var(--font-mono); font-size: 9px; color: var(--text-3);
    font-weight: 700; letter-spacing: 0.5px;
    display: flex; align-items: center; gap: 5px;
}
.field label .val { color: var(--accent); font-weight: 400; }
.row-2 { display: flex; gap: 8px; align-items: flex-end; }

input[type="text"],
input[type="number"],
select {
    background: var(--bg-0); border: 1px solid var(--border);
    color: var(--text-1); padding: 8px 10px;
    border-radius: var(--radius-sm); font-size: 12px;
    font-family: var(--font-sans); width: 100%; min-width: 0;
    outline: none; transition: border-color var(--tr);
}
input:focus { border-color: var(--accent); }

/* ─── Range Slider (larger touch target) ─── */
input[type="range"] {
    -webkit-appearance: none; appearance: none;
    width: 100%; height: 6px;
    background: var(--bg-3); border-radius: 3px;
    outline: none; cursor: pointer;
    margin: 4px 0;
}
input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px; height: 20px;
    background: var(--text-1); border-radius: 50%;
    border: 2px solid var(--bg-0); cursor: pointer;
}
input[type="range"]::-webkit-slider-thumb:hover { background: var(--accent); }
input[type="range"]::-moz-range-thumb {
    width: 20px; height: 20px;
    background: var(--text-1); border-radius: 50%;
    border: 2px solid var(--bg-0); cursor: pointer;
}

/* ─── Color Input ─── */
.color-input-wrap { position: relative; }
input[type="color"] {
    -webkit-appearance: none; appearance: none;
    width: 100%; height: 32px; background: none;
    border: 1px solid var(--border); border-radius: var(--radius-sm);
    cursor: pointer; padding: 2px;
}
input[type="color"]::-webkit-color-swatch-wrapper { padding: 0; }
input[type="color"]::-webkit-color-swatch { border: none; border-radius: 4px; }

/* ─── Checkbox ─── */
input[type="checkbox"] {
    accent-color: var(--accent); margin-right: 4px;
    cursor: pointer; width: 16px; height: 16px;
}

/* ─── Color Palette ─── */
.color-palette { display: flex; gap: 4px; flex-wrap: wrap; min-height: 24px; }
.color-swatch {
    width: 26px; height: 26px; border-radius: 4px;
    border: 2px solid transparent; cursor: pointer;
    transition: all var(--tr); padding: 0;
}
.color-swatch:hover { border-color: var(--text-2); transform: scale(1.1); }
.color-swatch.active { border-color: var(--accent); }

/* ─── Presets ─── */
.preset-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
.preset-btn, .size-preset-btn {
    padding: 8px 10px; background: var(--bg-3);
    border: 1px solid var(--border); color: var(--text-2);
    font-family: var(--font-mono); font-size: 10px; font-weight: 700;
    border-radius: var(--radius-sm); cursor: pointer;
    transition: all var(--tr);
}
.preset-btn:hover, .size-preset-btn:hover { color: var(--text-1); border-color: var(--border-hover); }
.preset-btn:active, .size-preset-btn:active { transform: scale(0.97); }
.preset-btn.active { border-color: var(--accent); color: var(--accent); background: var(--accent-dim); }

/* ─── Path List ─── */
.path-list {
    display: flex; flex-direction: column; gap: 3px;
    max-height: 180px; overflow-y: auto;
}
.path-item {
    display: flex; align-items: center; gap: 7px;
    padding: 7px 9px; background: var(--bg-3);
    border: 1px solid transparent; border-radius: var(--radius-sm);
    cursor: pointer; transition: all var(--tr); user-select: none;
}
.path-item:hover { border-color: var(--border-hover); }
.path-item.active { border-color: var(--accent); background: var(--accent-dim); }
.path-color {
    width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0;
}
.path-name {
    flex: 1; font-family: var(--font-mono); font-size: 10px;
    color: var(--text-1); overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.path-del-btn {
    width: 22px; height: 22px; background: none;
    border: 1px solid var(--border); color: var(--text-3);
    border-radius: 4px; cursor: pointer; font-size: 14px;
    display: grid; place-items: center; padding: 0;
    transition: all var(--tr);
}
.path-del-btn:hover { color: var(--danger); border-color: var(--danger); }

/* ═══════════════════════════════════
   DESKTOP LAYOUT
   ═══════════════════════════════════ */
@media (min-width: 768px) {
    #app { flex-direction: row; }
    #controls {
        order: -1; width: var(--panel-w); min-width: var(--panel-w);
        max-height: 100dvh; height: 100dvh;
        border-top: none; border-right: 1px solid var(--border);
    }
    #canvas-area {
        flex: 1; height: 100dvh; max-height: 100dvh; min-height: unset;
        background-image: radial-gradient(circle at 50% 50%, rgba(108,138,255,0.02) 0%, transparent 60%);
    }
    #drawCanvas {
        box-shadow: 0 4px 30px rgba(0,0,0,0.4), 0 0 0 1px rgba(255,255,255,0.04);
        border-radius: 3px;
    }
    .scroll-container { padding: 16px; }
}

/* ═══════════════════════════════════
   MOBILE LAYOUT
   ═══════════════════════════════════ */
@media (max-width: 767px) {
    #canvas-area {
        flex: 0 0 40dvh;
        min-height: 120px;
        max-height: 45dvh;
    }
    #controls {
        flex: 1 1 0;
        min-height: 0;
        max-height: none;
    }
    input[type="number"] { font-size: 16px; }
    .tool-btn { width: 40px; height: 38px; }

    /* bigger touch targets on mobile */
    .btn-action { padding: 11px 10px; font-size: 10px; }
    input[type="range"]::-webkit-slider-thumb { width: 24px; height: 24px; }
    input[type="range"]::-moz-range-thumb { width: 24px; height: 24px; }
    .color-swatch { width: 30px; height: 30px; }
    input[type="checkbox"] { width: 20px; height: 20px; }
}