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

html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    font-family: 'Courier New', monospace;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background: #0a0e27;
    overflow: hidden;
}

/* ========== APP CONTAINER (Mobile App Look) ========== */
.app-container {
    display: flex;
    flex-direction: row;
    width: 100%;
    height: 100vh;
    overflow: hidden;
}

/* ========== HEADER (Mobile App Style) ========== */
.app-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 0 16px;
    height: 56px;
    flex-shrink: 0;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
}

.menu-btn {
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    transition: background 0.2s ease;
    -webkit-tap-highlight-color: transparent;
}

.menu-btn:active {
    background: rgba(255, 255, 255, 0.15);
}

.hamburger {
    display: flex;
    flex-direction: column;
    gap: 4px;
    width: 24px;
    height: 20px;
}

.hamburger span {
    width: 100%;
    height: 2.5px;
    background: white;
    border-radius: 2px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.menu-btn[aria-expanded="true"] .hamburger span:nth-child(1) {
    transform: rotate(45deg) translate(8px, 8px);
}

.menu-btn[aria-expanded="true"] .hamburger span:nth-child(2) {
    opacity: 0;
    transform: translateX(-10px);
}

.menu-btn[aria-expanded="true"] .hamburger span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

.app-title {
    font-size: 1.1rem;
    font-weight: 600;
    flex: 1;
    text-align: center;
    letter-spacing: 0.5px;
}

.header-spacer {
    width: 40px;
    flex-shrink: 0;
}

/* ========== CANVAS AREA (Main Drawing Grid) ========== */
.canvas-area {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #fff;
    overflow: hidden;
    position: relative;
    padding: 8px;
    margin-top: 56px;
    width: 100%;
    min-height: 0;
}

.grid {
    display: grid;
    gap: 0;
    background: #333;
    padding: 6px;
    border-radius: 6px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.2);
    max-width: 100%;
    max-height: 100%;
}

.pixel {
    cursor: crosshair;
    background: white;
    transition: background-color 0.05s;
    touch-action: none;
    user-select: none;
    -webkit-user-select: none;
    border: 1px solid #ddd;
}

.pixel:active {
    filter: brightness(0.95);
}

/* ========== CONTROL PANEL (Overlay Slide-In) ========== */
.control-panel {
    position: fixed;
    top: 56px;
    left: 0;
    width: 100%;
    max-width: 320px;
    height: calc(100vh - 56px);
    background: white;
    box-shadow: 2px 0 12px rgba(0, 0, 0, 0.15);
    z-index: 200;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    padding: 16px;
    transform: translateX(-100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.app-container.menu-open .control-panel {
    transform: translateX(0);
}

.control-section {
    margin-bottom: 20px;
    padding-bottom: 16px;
    border-bottom: 1px solid #eee;
}

.control-section:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.section-title {
    font-size: 0.85rem;
    font-weight: 700;
    color: #333;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 12px;
    display: block;
}

.select-control {
    width: 100%;
    padding: 10px 12px;
    border: 1.5px solid #e0e0e0;
    border-radius: 6px;
    font-size: 0.95rem;
    background: #f9f9f9;
    color: #333;
    cursor: pointer;
    transition: all 0.2s ease;
    -webkit-appearance: none;
    appearance: none;
}

.select-control:active,
.select-control:focus {
    outline: none;
    border-color: #667eea;
    background: white;
}

/* ========== COLOR PICKER ========== */
.color-picker-wrapper {
    margin-bottom: 12px;
}

.color-label {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    color: #555;
    margin-bottom: 6px;
    text-transform: uppercase;
}

.color-picker {
    width: 100%;
    height: 50px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    cursor: pointer;
    transition: border-color 0.2s ease;
    -webkit-appearance: none;
    appearance: none;
}

.color-picker::-webkit-color-swatch-wrapper {
    padding: 2px;
}

.color-picker::-webkit-color-swatch {
    border: none;
    border-radius: 4px;
}

.color-picker:active,
.color-picker:focus {
    outline: none;
    border-color: #667eea;
}

/* ========== CURRENT COLOR DISPLAY ========== */
.current-color-box {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
}

.color-preview {
    width: 44px;
    height: 44px;
    border-radius: 8px;
    border: 2px solid #e0e0e0;
    flex-shrink: 0;
    background: #FF0000;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* ========== PRESET COLORS ========== */
.preset-colors {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
}

.color-btn {
    width: 100%;
    aspect-ratio: 1 / 1;
    border: 2px solid transparent;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    background-color: #FF0000;
    position: relative;
    -webkit-tap-highlight-color: transparent;
}

.color-btn:active {
    transform: scale(0.93);
}

.color-btn.active {
    border-color: #667eea;
    box-shadow: 0 0 0 2px white, 0 0 8px rgba(102, 126, 234, 0.4);
}

.color-btn::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.15);
    pointer-events: none;
}

/* ========== TOOL BUTTONS ========== */
.tool-btn {
    display: block;
    width: 100%;
    padding: 12px 16px;
    margin-bottom: 8px;
    border: none;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    background: #667eea;
    color: white;
    box-shadow: 0 2px 6px rgba(102, 126, 234, 0.2);
    -webkit-tap-highlight-color: transparent;
}

.tool-btn:active {
    transform: scale(0.97);
    box-shadow: 0 1px 3px rgba(102, 126, 234, 0.15);
}

.tool-btn.active {
    background: #5f6fdc;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.15);
}

.tool-btn--danger {
    background: #ef5350;
    box-shadow: 0 2px 6px rgba(239, 83, 80, 0.2);
}

.tool-btn--danger:active {
    background: #e53935;
}

.tool-btn--success {
    background: #66bb6a;
    box-shadow: 0 2px 6px rgba(102, 187, 106, 0.2);
}

.tool-btn--success:active {
    background: #558b2f;
}

/* ========== BACKDROP (Menu Overlay) ========== */
.backdrop {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0);
    z-index: 150;
    pointer-events: none;
    transition: background 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.app-container.menu-open .backdrop {
    background: rgba(0, 0, 0, 0.3);
    pointer-events: auto;
}

/* ========== MOBILE OPTIMIZATIONS ========== */
@media (max-width: 480px) {
    .app-header {
        padding: 0 12px;
        height: 52px;
    }

    .app-title {
        font-size: 1rem;
    }

    .canvas-area {
        margin-top: 52px;
        padding: 6px;
    }

    .control-panel {
        max-width: 100%;
        padding: 12px;
        top: 52px;
        height: calc(100vh - 52px);
    }

    .section-title {
        font-size: 0.8rem;
    }

    .select-control {
        padding: 8px 10px;
        font-size: 0.9rem;
    }

    .tool-btn {
        padding: 10px 14px;
        font-size: 0.9rem;
    }

    .preset-colors {
        gap: 6px;
    }

    .color-picker {
        height: 44px;
    }

    .color-preview {
        width: 40px;
        height: 40px;
    }
}

/* ========== VERY SMALL SCREENS ========== */
@media (max-width: 360px) {
    .app-header {
        padding: 0 10px;
        height: 48px;
    }

    .app-title {
        font-size: 0.95rem;
    }

    .canvas-area {
        margin-top: 48px;
        padding: 4px;
    }

    .control-panel {
        padding: 10px;
        top: 48px;
        height: calc(100vh - 48px);
    }

    .preset-colors {
        grid-template-columns: repeat(3, 1fr);
        gap: 6px;
    }
}

/* ========== LANDSCAPE MODE ========== */
@media (orientation: landscape) and (max-height: 500px) {
    .app-header {
        height: 48px;
        position: fixed;
    }

    .canvas-area {
        padding: 6px;
        margin-top: 48px;
    }

    .grid {
        padding: 4px;
    }

    .control-panel {
        top: 48px;
        height: calc(100vh - 48px);
        max-width: 280px;
    }

    .control-section {
        margin-bottom: 12px;
        padding-bottom: 10px;
    }

    .section-title {
        font-size: 0.75rem;
        margin-bottom: 8px;
    }

    .tool-btn {
        padding: 8px 12px;
        margin-bottom: 6px;
        font-size: 0.85rem;
    }

    .preset-colors {
        grid-template-columns: repeat(4, 1fr);
        gap: 6px;
    }
}

/* ========== TABLET & UP (768px+) ========== */
@media (min-width: 768px) {
    .app-container {
        flex-direction: row;
    }

    .app-header {
        display: none;
    }

    /* Sidebar visible */
    .control-panel {
        position: static;
        top: auto;
        left: auto;
        width: 280px;
        max-width: none;
        height: 100vh;
        background: #f8f9fa;
        box-shadow: 2px 0 12px rgba(0, 0, 0, 0.1);
        z-index: 10;
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
        padding: 16px;
        transform: translateX(0) !important;
        transition: none;
        flex-shrink: 0;
    }

    .app-container.menu-open .control-panel {
        transform: translateX(0) !important;
    }

    /* Canvas area fills remaining space */
    .canvas-area {
        flex: 1;
        margin-top: 0;
        width: auto;
        padding: 12px;
    }

    .grid {
        padding: 8px;
    }

    /* Hide menu button */
    .menu-btn {
        display: none;
    }

    /* Hide backdrop */
    .backdrop {
        display: none !important;
    }
}

/* ========== DESKTOP (1025px+) ========== */
@media (min-width: 1025px) {
    body {
        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        display: flex;
        justify-content: center;
        align-items: center;
        padding: 20px;
    }

    .app-container {
        max-width: 1400px;
        height: auto;
        min-height: 80vh;
        border-radius: 16px;
        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
        background: white;
    }

    .control-panel {
        width: 300px;
        height: auto;
        background: #f8f9fa;
        box-shadow: none;
        padding: 20px;
        border-right: 1px solid #e0e0e0;
        flex-shrink: 0;
    }

    .canvas-area {
        flex: 1;
        padding: 20px;
        min-height: auto;
    }

    .grid {
        padding: 10px;
    }
}