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

html,body{
    width: 100%;
}

html{
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background-color: var(--bg-primary-color);
    color: var(--text-primary-color);
}

main{
    width: 100%;
}

main section{
    width: 100%;
    padding: var(--padding-2xl);
    display: flex;
    gap: var(--gutter-large);
}

.btn{
    padding: var(--padding-small) var(--padding-large);
    border: none;
    outline: none;
    border-radius: var(--border-radius-medium);
    background-color: var(--bg-active-color);
    cursor: pointer;
    color: var(--bg-primary-color);
    min-height: 44px;
    font-size: var(--font-size-medium);
}

#reset-btn{
    background-color: var(--bg-danger-color);
    color: var(--text-primary-color);
}

#download-btn{
    background-color: var(--bg-success-color);
    color: var(--text-primary-color);
}

main section .left{
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--gutter-large);
    width: 70%;
    padding: var(--padding-large);
}

main section .right{
    width: 30%;
    background-color: var(--bg-secondary-color);
    padding: var(--padding-large);
    border-radius: var(--border-radius-large);
    display: flex;
    flex-direction: column;
    gap: var(--gutter-medium);
}

main section .top{
    display: flex;
    align-items: center;
    gap: var(--gutter-medium);
    padding: var(--padding-large);
}

main section .bottom{
    background-color: var(--bg-secondary-color);   
    width: 100%;
    padding: var(--padding-2xl);
    aspect-ratio: 5/3;
    border-radius: var(--border-radius-xl);
    display: flex;
    justify-content: center;
    align-items: center;
}

main section .bottom .placeholder{
    display: flex;
    flex-direction: column;
    align-items: center;
    opacity: 0.6;
    gap: var(--gutter-medium);
}

main section .bottom .placeholder i {
    font-size: var(--font-size-8xl);
}

main section .bottom .placeholder p {
    font-size: var(--font-size-2xl);
}

main section .right .filters{
    display: flex;
    flex-direction: column;
    gap: var(--gutter-large);
}

main section .right .filter {
    width: 100%;
}

main section .right .filter input {
    width: 100%;
    outline: none;
    margin-top: var(--margin-small);
    appearance: none;
}

main section .right .filter input::-webkit-slider-runnable-track {
    background-color: var(--bg-active-color);
    height: 3px;
}

main section .right .filter input::-webkit-slider-thumb {
    cursor: pointer;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background-color: brown;
    margin-top: -8.5px;
}

canvas{
    max-width: 90%;
    max-height: 80vh;
    display: none;
}

.presets{
    display: flex;
    flex-wrap: wrap;
    gap: var(--gutter-small);
}

/* Desktop / shared states */
.btn:disabled{
    opacity: 0.5;
    cursor: not-allowed;
}

.btn.active{
    background-color: var(--text-secondary-color);
    color: var(--text-active-color);
}

.filter p{
    font-size: var(--font-size-small);
    color: var(--text-secondary-color);
}

/* Mobile-first UI containers (hidden on desktop by default) */
.mobile-ui{
    display: none;
}

/* Bottom swipeable filter bar */
.mobile-filter-bar{
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    padding: var(--padding-small) 0;
    background-color: var(--bg-secondary-color);
    border-top: 1px solid rgba(255,255,255,0.08);
    border-top: 1px solid rgba(255,255,255,0.08);
    z-index: 30;
}

.mobile-filter-track{
    display: inline-flex;
    gap: var(--gutter-small);
    padding: 0 var(--padding-medium);
    overflow-x: auto;
    white-space: nowrap;
    width: 100%;
    scroll-snap-type: x mandatory;
}

.mobile-filter-track::-webkit-scrollbar{
    height: 0;
}

.mobile-filter-btn{
    flex: 0 0 auto;
    scroll-snap-align: start;
}

.mobile-filter-btn.active{
    background-color: var(--text-secondary-color);
    color: var(--text-active-color);
}

.mobile-slider-overlay{
    position: fixed;
    left: 0;
    right: 0;
    bottom: calc(3.5rem + env(safe-area-inset-bottom));
    padding: var(--padding-medium);
    background-color: var(--bg-secondary-color);
    border-top: 1px solid rgba(255,255,255,0.1);
    z-index: 35;
    display: none;
}

.mobile-slider-overlay.open{
    display: block;
}

.mobile-slider-content{
    display: flex;
    flex-direction: column;
    gap: var(--gutter-small);
}

.mobile-slider-label{
    font-size: var(--font-size-small);
    color: var(--text-secondary-color);
}

.mobile-filters,
.mobile-presets,
.mobile-actions{
    display: flex;
    flex-wrap: wrap;
    gap: var(--gutter-small);
}

/* Action buttons reuse generic .btn layout */

/* Presets drawer */
.presets-toggle{
    padding-inline: var(--padding-medium);
}

.presets-drawer{
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: min(280px, 75vw);
    background-color: rgba(17,17,17,0.98);
    border-left: 1px solid rgba(255,255,255,0.08);
    box-shadow: -4px 0 16px rgba(0,0,0,0.6);
    transform: translateX(100%);
    transition: transform 0.25s ease-out;
    z-index: 35;
    display: flex;
    flex-direction: column;
    padding: var(--padding-medium);
    gap: var(--gutter-medium);
}

.presets-drawer.open{
    transform: translateX(0);
}

.presets-drawer-header{
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.presets-drawer-body{
    flex: 1;
    overflow-y: auto;
}

.presets-drawer-body .mobile-presets{
    display: flex;
    flex-direction: column;
    gap: var(--gutter-small);
}

/* Responsive layout (keeps desktop the same) */
@media (max-width: 900px) {
    main section{
        padding: var(--padding-large);
        flex-direction: column;
        gap: var(--gutter-large);
    }

    main section .left{
        width: 100%;
    }

    /* Hide desktop editor panel on mobile; use bottom nav instead */
    main section .right{
        width: 100%;
        display: none;
    }

    main section .top{
        width: 100%;
        flex-wrap: wrap;
        justify-content: center;
        padding: var(--padding-medium);
    }

    main section .bottom{
        padding: var(--padding-large);
        aspect-ratio: auto;
        min-height: 40vh;
    }

    canvas{
        max-width: 100%;
        max-height: 60vh;
    }

    /* Reserve space for bottom filter bar */
    main{
        padding-bottom: 6rem;
    }

    .mobile-ui{
        display: block;
    }
}

@media (max-width: 480px) {
    main section{
        padding: var(--padding-medium);
    }

    main section .top{
        gap: var(--gutter-small);
    }

    .top .btn{
        flex: 1 1 45%;
        text-align: center;
    }

    main section .bottom .placeholder i{
        font-size: 5rem;
    }

    main section .bottom .placeholder p{
        font-size: var(--font-size-xl);
        text-align: center;
    }
}

/* Developer Footer */
.developer-footer {
    width: 100%;
    padding: var(--padding-xl);
    background-color: var(--bg-secondary-color);
    text-align: center;
    margin-top: var(--margin-2xl);
    border-top: 1px solid rgba(255,255,255,0.08);
}

.footer-content h3 {
    font-size: var(--font-size-large);
    margin-bottom: var(--margin-small);
}

.footer-content p {
    font-size: var(--font-size-small);
    color: var(--text-tertiary-color);
    margin-bottom: var(--margin-small);
}

.footer-links {
    margin-top: var(--margin-medium);
    display: flex;
    justify-content: center;
    gap: var(--gutter-medium);
    flex-wrap: wrap;
}

.footer-links a {
    text-decoration: none;
    color: var(--text-secondary-color);
    font-size: var(--font-size-small);
    transition: 0.2s ease;
}

.footer-links a:hover {
    color: var(--bg-active-color);
}