body {
    margin: 0;
    background-color: black;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    font-size: 0.8rem;
    font-weight: 500;
}

.header {
    position: sticky;
    background: black;
    color: white;
    text-align: center;
    padding: 20px 0 16px 0;
    box-shadow: 0 4px 20px rgba(71, 184, 255, 0.15), inset 0 1px 0 rgba(255, 255, 255, 0.1);
    border-bottom: 1px solid rgba(71, 184, 255, 0.2);
    transition: all 0.5s;
}

.header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 1.5px;
    margin: 0;
    background: linear-gradient(135deg, #47b8ff 0%, #00d4ff 50%, #47b8ff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 0 30px rgba(71, 184, 255, 0.3);
    filter: drop-shadow(0 0 8px rgba(71, 184, 255, 0.2));
    text-transform: uppercase;
}

.btn-primary {
    --clr-font-main: hsla(0 0% 20% / 100);
    --btn-bg-1: hsla(194 100% 69% / 1);
    --btn-bg-2: hsla(217 100% 56% / 1);
    --btn-bg-color: hsla(360 100% 100% / 1);
    --radii: 0.4em;

    cursor: pointer;
    padding: 0.5em 1em;

    font-size: 1.1em;

    transition: 0.6s, font-weight 0.6s, text-shadow 0.6s;
    background-size: 280% auto;
    background-image: linear-gradient(325deg,
            var(--btn-bg-2) 0%,
            var(--btn-bg-1) 55%,
            var(--btn-bg-2) 90%);

    border: none;
    border-radius: var(--radii);
    color: var(--btn-bg-color);

    box-shadow:
        0 0 10px rgba(71, 184, 255, 0.4),
        0 3px 4px -1px rgba(58, 125, 233, 0.25),
        inset 2px 2px 4px rgba(175, 230, 255, 0.5),
        inset -2px -2px 4px rgba(19, 95, 216, 0.35);
}

.btn-primary:hover {
    background-position: right top;
}

@media (prefers-reduced-motion: reduce) {
    .btn-primary {
        transition: linear;
    }
}

.btn-danger {
    --btn-bg-1: hsl(0 85% 60%);
    --btn-bg-2: hsl(0 75% 45%);
}

.btn-safe {
    --btn-bg-1: hsl(140, 80%, 60%);
    --btn-bg-2: hsl(140, 70%, 45%);
}

.btn-primary:disabled {
    cursor: not-allowed;
    opacity: 0.6;

    background-image: none;
    background-color: #777;

    box-shadow: none;
}

.btn-primary.selected {
    --btn-bg-1: #a259ff;
    --btn-bg-2: #6a00f4;
    background-image: linear-gradient(325deg, var(--btn-bg-2) 0%, var(--btn-bg-1) 100%);
    color: #fff;
    font-weight: bold;
    z-index: 1;
}

.panel-btn {
    width: 100%;
    max-width: 280px;
}

.container {
    display: flex;
    flex-direction: row;
    align-items: flex-start;
    justify-content: center;
    gap: 32px;
    max-width: 1600px;
    margin: 0 auto;
    padding: 24px;
}

.left-panel,
.right-panel {
    width: 300px;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
    flex-shrink: 0;
}

.dropdown {
    position: relative;
    display: inline-block;
}

#dropdownBtn {
    width: 100%;
    padding: 10px 16px;
    cursor: pointer;
    font-size: 14px;
    color: #fff;
    border: none;
    border-radius: 0.4em;
    background-size: 280% auto;
    background-image: linear-gradient(325deg,
            hsla(217 100% 56% / 1) 0%,
            hsla(194 100% 69% / 1) 55%,
            hsla(217 100% 56% / 1) 90%);
    box-shadow:
        0 0 10px rgba(71, 184, 255, 0.35),
        0 3px 4px -1px rgba(58, 125, 233, 0.25),
        inset 2px 2px 4px rgba(175, 230, 255, 0.45),
        inset -2px -2px 4px rgba(19, 95, 216, 0.3);
    transition: background-position 0.6s ease;
}

#dropdownBtn:hover {
    background-position: right top;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    margin-top: 8px;
    background: linear-gradient(325deg, #16469a 0%, #2097ca 55%, #16469a 90%);
    border: 1px solid rgba(121, 207, 255, 0.45);
    min-width: 180px;
    display: none;
    border-radius: 0.4em;
    overflow: hidden;
    z-index: 10;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.35);
}

.dropdown-menu.show {
    display: block;
}

.dropdown-item {
    padding: 10px;
    cursor: pointer;
    color: #fff;
    font-weight: 600;
    transition: background-color 0.2s ease;
}

.dropdown-item:hover {
    background-color: rgba(255, 255, 255, 0.16);
}

.slider-container {
    display: flex;
    flex-direction: column;
    gap: 10px;
    background: linear-gradient(135deg, #1a1a1a 0%, #232526 100%);
    border-radius: 0.5em;
    padding: 8px 10px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4), inset 0 1px 0 rgba(255, 255, 255, 0.05);
    border: 1px solid #2a3234;
}

.slider-control:disabled {
    accent-color: #888;   /* Modern browsers */
    cursor: not-allowed;
    opacity: 0.6;
}

.slider-control:disabled + .slider-value,
.slider-container:has(.slider-control:disabled) label {
    color: #aaa;
}

input[type="range"].slider-control {
    -webkit-appearance: none;
    appearance: none;
    width: 260px;
    max-width: 100%;
    height: 8px;
    background: linear-gradient(90deg, #1e3a8a 0%, #3b82f6 50%, #06b6d4 100%);
    border-radius: 4px;
    outline: none;
    margin: 8px 0;
    padding: 0;
    box-shadow: 0 2px 6px rgba(59, 130, 246, 0.2), inset 0 1px 2px rgba(0, 0, 0, 0.3);
    position: relative;
}

input[type="range"].slider-control::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: linear-gradient(135deg, #3b82f6 0%, #06b6d4 100%);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4), 0 0 0 2px #232526;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    margin-top: -5px;
}

input[type="range"].slider-control::-webkit-slider-thumb:hover {
    transform: scale(1.15);
    box-shadow: 0 6px 16px rgba(59, 130, 246, 0.5), 0 0 0 2px #232526;
}

input[type="range"].slider-control::-webkit-slider-thumb:active {
    transform: scale(1.1);
}

input[type="range"].slider-control::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: linear-gradient(135deg, #3b82f6 0%, #06b6d4 100%);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4), 0 0 0 2px #232526;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
}

input[type="range"].slider-control::-moz-range-thumb:hover {
    transform: scale(1.15);
    box-shadow: 0 6px 16px rgba(59, 130, 246, 0.5), 0 0 0 2px #232526;
}

input[type="range"].slider-control::-moz-range-thumb:active {
    transform: scale(1.1);
}

input[type="range"].slider-control::-ms-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: linear-gradient(135deg, #3b82f6 0%, #06b6d4 100%);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4), 0 0 0 2px #232526;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
}

input[type="range"].slider-control::-webkit-slider-runnable-track {
    height: 8px;
    border-radius: 4px;
    background: transparent;
}

input[type="range"].slider-control::-moz-range-track {
    height: 8px;
    border-radius: 4px;
    background: transparent;
}

input[type="range"].slider-control::-ms-fill-lower,
input[type="range"].slider-control::-ms-fill-upper {
    background: transparent;
}

input[type="range"].slider-control:focus {
    outline: none;
}

input[type="range"].slider-control:focus::-webkit-slider-thumb {
    opacity: 0.9;
}

input[type="range"].slider-control:focus::-moz-range-thumb {
    opacity: 0.9;
}

input[type="range"].slider-control:focus::-ms-thumb {
    opacity: 0.8;
}

input[type="range"].slider-control::-ms-tooltip {
    display: none;
}

.slider-value,
.log-value {
    font-weight: 700;
    color: #06b6d4;
    background: rgba(59, 130, 246, 0.1);
    padding: 4px 10px;
    border-radius: 0.4em;
    margin-left: 8px;
    font-size: 0.95em;
    letter-spacing: 0.3px;
    border: 1px solid rgba(59, 130, 246, 0.2);
}

.toggle-control {
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
    width: 100%;
    padding-left: 0;
    margin-bottom: 0;
    cursor: pointer;
    font-size: 0.95rem;
    color: #fff;
    font-weight: 600;
    user-select: none;
}

.toggle-label-text {
    line-height: 1.3;
    padding-right: 12px;
}

.toggle-control input {
    position: absolute;
    opacity: 0;
    height: 0;
    width: 0;
    pointer-events: none;
}

.toggle-control input:checked~.control {
    background-size: 280% auto;
    background-image: linear-gradient(325deg,
            hsla(217 100% 56% / 1) 0%,
            hsla(194 100% 69% / 1) 55%,
            hsla(217 100% 56% / 1) 90%);
    box-shadow:
        0 0 10px rgba(71, 184, 255, 0.35),
        0 3px 4px -1px rgba(58, 125, 233, 0.25),
        inset 2px 2px 4px rgba(175, 230, 255, 0.45),
        inset -2px -2px 4px rgba(19, 95, 216, 0.3);
}

.toggle-control input:checked~.control:after {
    left: 31px;
}

.toggle-control .control {
    position: relative;
    flex-shrink: 0;
    height: 28px;
    width: 56px;
    border-radius: 14px;
    background-size: 280% auto;
    background-image: linear-gradient(325deg, #4d4d4d 0%, #6a6a6a 55%, #4d4d4d 90%);
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow:
        inset 2px 2px 4px rgba(255, 255, 255, 0.14),
        inset -2px -2px 4px rgba(0, 0, 0, 0.35),
        0 4px 10px rgba(0, 0, 0, 0.35);
    transition: background-position 0.35s ease, box-shadow 0.25s ease;
}

.toggle-control:hover .control {
    background-position: right top;
}

.toggle-control .control:after {
    content: "";
    position: absolute;
    left: 3px;
    top: 3px;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: linear-gradient(135deg, #ffffff 0%, #dce9ff 100%);
    box-shadow: 0 3px 8px rgba(0, 0, 0, 0.35);
    transition: left 0.15s ease-in, transform 0.15s ease-in;
}

.toggle-control input:active~.control:after {
    transform: scale(0.96);
}

.toggle-control input:disabled~.control {
    background: #888 !important;
    opacity: 0.6;
    cursor: not-allowed;
    box-shadow: none;
}

.toggle-control input:disabled~.control:after {
    background: #ccc !important;
    box-shadow: none;
    cursor: not-allowed;
}

.toggle-control input:disabled~.toggle-label-text {
    color: #aaa;
}

.grid-menu {
    display: flex;
    align-items: center;
    justify-content: space-around;
    gap: 20px;
    width: 100%;
}

.grid-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    gap: 20px;
    flex-shrink: 0;
}

.grid {
    height: 500px;
    width: 500px;
    display: grid;
    border: 1px solid white;
    background: #181818;
}

.cell {
    background: rgb(255, 255, 255);
    border: 1px solid black;
    transition: background 0.2s, box-shadow 0.3s;
}

.cell.obstacle {
    background-color: #000;
}

.cell.start {
    background-color: #008000 !important;
}

.cell.goal {
    background-color: #00277b !important;
}

.hover-start {
    background-color: #0fffc3 !important;
    box-shadow: 0 0 8px 2px #0fffc3cc;
}

.hover-goal {
    background-color: #a259ff !important;
    box-shadow: 0 0 8px 2px #a259ffcc;
}

.menu {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 10px;
    background-color: #333;
    border-radius: 0.4em;
    padding: 8px 10px;
    box-sizing: border-box;
    border: 1px solid #555;
    margin-bottom: 8px;
}

.menu h3,
.menu h2 {
    margin: 0;
    font-size: 1.1rem;
}

.submenu {
    padding: 12px;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    justify-content: center;
    gap: 12px;
    background-color: #1a1a1a;
    border-radius: 0.4em;
    width: 100%;
    box-sizing: border-box;
}

.submenu p {
    margin: 0 0 4px 0;
    font-size: 0.9rem;
    color: #aaa;
}

#steplog {
    font-size: 0.85rem;
    line-height: 1.8;
    color: #ddd;
}

#steplog>div {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
    padding: 8px 0;
    border-bottom: 1px solid #333;
    flex-wrap: wrap;
    overflow: hidden;
}

#steplog>div:last-child {
    border-bottom: none;
}

.log-value {
    font-weight: 700;
    font-size: 1.1em;
    color: #47b8ff;
    background: rgba(71, 184, 255, 0.1);
    padding: 4px 10px;
    border-radius: 0.3em;
    border: 1px solid rgba(71, 184, 255, 0.3);
    min-width: 60px;
    max-width: 100px;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    letter-spacing: 0.5px;
    flex-shrink: 0;
    word-break: break-word;
}

@media screen and (max-width: 900px) {
    .container {
        flex-direction: column;
    }
}

.footer,
footer {
    background-color: #000000;
    color: #ffffff;
    text-align: center;
    padding: 40px 20px;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    font-size: 14px;
    letter-spacing: 1px;
}