* {
    font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
}

body {
    margin: 0;
    padding: 0;
    height: 100vh;
    background: linear-gradient(45deg, #ff9595, #4ecdc4);
    overflow-x: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
}

#topbar {
    position: relative;
    width: 100%;
    height: 100px;
    display: flex;
    justify-content: center;
    align-items: center;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
    transition: all 0.3s ease;
}

#topbar.reading {
    background: rgba(94, 242, 178, 0.2);
}

#topbar.meaning {
    background: rgba(151, 94, 242, 0.2);
}
#topbar.choice {
    background: rgba(242, 165, 94, 0.2);
}
#kanji {
    font-size: 50px;
    color: #333;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}
#kanjiinput {
    width: 200px;
    height: 30px;
    font-size: 20px;
    text-align: center;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 8px;
    padding: 8px 16px;
    color: #333;
}
#input {
    padding-top: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
}
#result {
    padding-top: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 20px;
    width: 100%;
}
#score {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 32px;
    color: rgba(255, 255, 255, 0.9);
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
    font-weight: 500;
    -webkit-font-smoothing: antialiased;
}

@keyframes scoreChange {
    0% {
        opacity: 1;
        transform: translate(-50%, -50%);
    }
    45% {
        opacity: 0;
        transform: translate(-50%, -40%);
    }
    55% {
        opacity: 0;
        transform: translate(-50%, -60%);
        color: rgba(94, 242, 178, 0.9);
    }
    100% {
        opacity: 1;
        transform: translate(-50%, -50%);
        color: rgba(255, 255, 255, 0.9);
    }
}

.score-animate {
    animation: scoreChange 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.hidden {
    display: none !important;
}

#start-screen {
    min-height: fit-content;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    gap: 20px;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 16px;
    padding: 20px;
    width: 90%;
    max-width: 500px;
    margin: 0 auto;
    box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
    max-height: 90vh;
    overflow: hidden;
}

#start-screen h1 {
    font-size: 40px;
    color: #333;
}

#start-button {
    padding: 15px 40px;
    font-size: 20px;
    background: rgba(94, 242, 178, 0.3);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
    margin-top: 10px;
}

#start-button:hover {
    background: rgba(94, 242, 178, 0.5);
}

#game-screen {
    height: 100vh;
    width: 100%;
    overflow-x: hidden;
    overflow-y: auto;
}

#win-screen {
    height: 100vh;
    overflow-y: auto;
}

#win-screen h1 {
    font-size: 40px;
    color: #333;
}

#win-screen p {
    font-size: 24px;
    color: #666;
}

#restart-button {
    padding: 15px 40px;
    font-size: 20px;
    background: rgba(94, 242, 178, 0.3);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#restart-button:hover {
    background: rgba(94, 242, 178, 0.5);
}

#chapter-select-wrapper {
    height: 400px;
    overflow-y: auto;
    padding: 20px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    width: 80%;
    margin: 0 auto;
}

#chapter-select {
    display: flex;
    flex-direction: column;
    gap: 10px;
    padding-right: 4px;
}

.chapter-group {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 8px;
    padding: 0;
}

.chapter-label {
    display: flex;
    align-items: center;
    padding: 12px;
    cursor: default;
}

.checkbox-wrapper {
    display: flex;
    align-items: center;
    margin-right: 8px;
}

.checkbox-wrapper input[type="checkbox"] {
    cursor: pointer;
}

.chapter-text {
    flex-grow: 1;
}

.arrow {
    margin-left: auto;
    transform: rotate(-90deg);
    transition: transform 0.3s ease;
    cursor: pointer;
    padding: 8px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
}

.arrow:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

.chapter-group.open .arrow {
    transform: rotate(0);
}

.subchapter-group {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-left: 24px;
    overflow: hidden;
    max-height: 0;
    opacity: 0;
    transform: translateY(-10px);
    transition: all 0.3s ease-out;
    padding: 0;
    margin-bottom: 0;
    visibility: hidden;
}

.chapter-group.open .subchapter-group {
    max-height: 1000px;
    opacity: 1;
    transform: translateY(0);
    transition: all 0.3s ease-in;
    padding-bottom: 12px;
    visibility: visible;
}

.subchapter-group label {
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 4px 0;
}

.subchapter-group input[type="checkbox"] {
    cursor: pointer;
}

#chapter-select input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    appearance: none;
    -webkit-appearance: none;
    background: rgba(255, 255, 255, 0.3);
    border: none;
    border-radius: 4px;
    position: relative;
    transition: all 0.3s ease;
    margin: 0;
    flex-shrink: 0;
}

#chapter-select input[type="checkbox"]:checked {
    background: rgba(94, 242, 178, 0.5);
}

#chapter-select input[type="checkbox"]:hover {
    background: rgba(255, 255, 255, 0.4);
}

#chapter-select input[type="checkbox"]:checked:hover {
    background: rgba(94, 242, 178, 0.6);
}

#chapter-select input[type="checkbox"]::after {
    content: "✓";
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0);
    color: #333;
    font-size: 14px;
    transition: transform 0.2s ease;
}

#chapter-select input[type="checkbox"]:checked::after {
    transform: translate(-50%, -50%) scale(1);
}

#review-button {
    padding: 15px 40px;
    font-size: 20px;
    background: rgba(242, 94, 94, 0.3);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
    margin: 10px;
}

#review-button:hover {
    background: rgba(242, 94, 94, 0.5);
}

/* Add styling for the start screen review button */
#start-review-button {
    padding: 15px 40px;
    font-size: 20px;
    background: rgba(242, 94, 94, 0.3);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
    margin: 5px auto;
    display: block;
}

#start-review-button:hover {
    background: rgba(242, 94, 94, 0.5);
}

/* Scrollbar styling */
#chapter-select-wrapper::-webkit-scrollbar {
    width: 8px;
    margin-right: 4px;
}

#chapter-select-wrapper::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
    margin: 4px;
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}

#chapter-select-wrapper::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-radius: 4px;
    border: 2px solid transparent;
    background-clip: padding-box;
    box-shadow:
        inset 0 0 8px rgba(255, 255, 255, 0.2),
        0 0 4px rgba(255, 255, 255, 0.1);
    transition: all 0.3s ease;
}

#chapter-select-wrapper::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.4);
    box-shadow:
        inset 0 0 10px rgba(255, 255, 255, 0.3),
        0 0 6px rgba(255, 255, 255, 0.2);
}

/* Add some padding to prevent content from touching scrollbar */
#chapter-select {
    padding-right: 4px;
}

/* Make sure content doesn't cause horizontal scroll */
#topbar,
#input,
#result {
    width: 100%;
    max-width: 100%;
    box-sizing: border-box; /* Include padding in width calculation */
}

#progress-container {
    width: 160px;
    height: 160px;
    margin: 20px auto;
    position: relative;
    padding: 8px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 50%;
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow:
        0 4px 24px -1px rgba(0, 0, 0, 0.1),
        inset 0 0 20px rgba(255, 255, 255, 0.2);
}

.progress-ring {
    transform: rotate(-90deg);
    filter: drop-shadow(0 0 10px rgba(94, 242, 178, 0.3));
}

.progress-ring__circle-bg {
    fill: none;
    stroke: rgba(255, 255, 255, 0.15);
    stroke-width: 12px;
    filter: blur(0.5px);
}

.progress-ring__circle {
    fill: none;
    stroke: rgba(94, 242, 178, 0.7);
    stroke-width: 12px;
    stroke-linecap: round;
    stroke-dasharray: 452.389;
    stroke-dashoffset: 452.389;
    transition: stroke-dashoffset 0.3s ease;
    filter: drop-shadow(0 0 4px rgba(94, 242, 178, 0.5))
        drop-shadow(0 -2px 6px rgba(94, 242, 178, 0.7));
}

.arrow {
    cursor: pointer;
    padding: 8px;
    user-select: none;
    transition: transform 0.3s ease;
}

.chapter-group.open .arrow {
    transform: rotate(0deg);
}

.arrow:not(.chapter-group.open .arrow) {
    transform: rotate(-90deg);
}

.subchapter {
    margin-bottom: 8px;
}

.subchapter-label {
    display: flex;
    align-items: center;
    padding: 8px;
    cursor: default;
}

.kanji-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-left: 24px;
    overflow: hidden;
    max-height: 0;
    opacity: 0;
    transform: translateY(-10px);
    transition: all 0.3s ease-out;
    visibility: hidden;
}

.subchapter.open .kanji-group {
    max-height: 2000px;
    opacity: 1;
    transform: translateY(0);
    transition: all 0.3s ease-in;
    padding-top: 8px;
    padding-bottom: 8px;
    visibility: visible;
}

.kanji-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 4px 0;
    cursor: pointer;
}

/* Add click handling for subchapter labels */
.subchapter-label {
    cursor: pointer;
}

/* Add after the existing #score styles (around line 81) */
@keyframes scoreIncrease {
    0% {
        transform: translate(-50%, -50%) scale(1.5);
        color: rgba(94, 242, 178, 0.9);
    }
    100% {
        transform: translate(-50%, -50%) scale(1);
        color: rgba(255, 255, 255, 0.9);
    }
}

.score-increase {
    animation: scoreIncrease 0.5s ease-out;
}

/* Multiple choice styles */
#multiple-choice {
    display: flex;
    flex-direction: column;
    gap: 15px;
    padding: 20px;
    width: 100%;
    max-width: 400px;
    margin: 0 auto;
}

.choice-option {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 12px;
    padding: 20px;
    font-size: 32px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    color: #333;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.1);
    box-shadow: 0 4px 16px 0 rgba(31, 38, 135, 0.2);
    user-select: none;
}

.choice-option:hover {
    background: rgba(255, 255, 255, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.4);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px 0 rgba(31, 38, 135, 0.3);
}

.choice-option:active {
    transform: translateY(0);
    box-shadow: 0 2px 10px 0 rgba(31, 38, 135, 0.2);
}

.choice-option.correct {
    background: rgba(94, 242, 178, 0.4);
    border: 1px solid rgba(94, 242, 178, 0.6);
    animation: correctAnswer 0.6s ease-out;
}

.choice-option.incorrect {
    background: rgba(242, 94, 94, 0.4);
    border: 1px solid rgba(242, 94, 94, 0.6);
    animation: incorrectAnswer 0.6s ease-out;
}

@keyframes correctAnswer {
    0% {
        transform: scale(1);
        background: rgba(94, 242, 178, 0.4);
    }
    50% {
        transform: scale(1.05);
        background: rgba(94, 242, 178, 0.6);
    }
    100% {
        transform: scale(1);
        background: rgba(94, 242, 178, 0.4);
    }
}

@keyframes incorrectAnswer {
    0% {
        transform: translateX(0);
        background: rgba(242, 94, 94, 0.4);
    }
    25% {
        transform: translateX(-5px);
        background: rgba(242, 94, 94, 0.6);
    }
    75% {
        transform: translateX(5px);
        background: rgba(242, 94, 94, 0.6);
    }
    100% {
        transform: translateX(0);
        background: rgba(242, 94, 94, 0.4);
    }
}

/* Max questions slider styling */
#max-questions-control {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    margin: 20px auto;
    padding: 20px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    width: 80%;
    max-width: 400px;
    box-sizing: border-box;
}

#max-questions-control label {
    font-size: 18px;
    color: #333;
    font-weight: 500;
    text-align: center;
}

#max-questions-value {
    color: #333;
    font-weight: bold;
    font-size: 20px;
}

#max-questions {
    width: 100%;
    height: 8px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 8px;
    outline: none;
    border: 1px solid rgba(255, 255, 255, 0.2);
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    box-sizing: border-box;
}

/* Firefox needs special handling */
@supports (-moz-appearance: none) {
    #max-questions {
        background: transparent;
        height: 8px;
    }
}

#max-questions:focus {
    outline: none;
    box-shadow: 0 0 0 2px rgba(94, 242, 178, 0.3);
}

/* WebKit browsers (Chrome, Safari) */
#max-questions::-webkit-slider-track {
    width: 100%;
    height: 8px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 8px;
    border: none;
    cursor: pointer;
}

#max-questions::-webkit-slider-thumb {
    appearance: none;
    -webkit-appearance: none;
    width: 24px;
    height: 24px;
    background: rgba(94, 242, 178, 0.8);
    border-radius: 50%;
    cursor: pointer;
    border: 2px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 2px 8px rgba(94, 242, 178, 0.4);
    transition: all 0.3s ease;
    margin-top: -8px;
}

#max-questions::-webkit-slider-thumb:hover {
    background: rgba(94, 242, 178, 1);
    transform: scale(1.1);
    box-shadow: 0 4px 12px rgba(94, 242, 178, 0.6);
    border-color: rgba(255, 255, 255, 0.5);
}

/* Firefox */
#max-questions::-moz-range-track {
    width: 100%;
    height: 8px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 8px;
    border: none;
    cursor: pointer;
}

#max-questions::-moz-range-thumb {
    width: 24px;
    height: 24px;
    background: rgba(94, 242, 178, 0.8);
    border-radius: 50%;
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 8px rgba(94, 242, 178, 0.4);
    transition: all 0.3s ease;
}

#max-questions::-moz-range-thumb:hover {
    background: rgba(94, 242, 178, 1);
    box-shadow: 0 4px 12px rgba(94, 242, 178, 0.6);
}

/* Firefox focus fix */
#max-questions::-moz-focus-outer {
    border: 0;
}

#max-questions::-moz-range-progress {
    background: rgba(94, 242, 178, 0.3);
    height: 8px;
    border-radius: 8px;
}

/* Internet Explorer/Edge */
#max-questions::-ms-track {
    width: 100%;
    height: 8px;
    background: transparent;
    border-color: transparent;
    color: transparent;
    cursor: pointer;
}

#max-questions::-ms-fill-lower {
    background: rgba(255, 255, 255, 0.3);
    border-radius: 8px;
}

#max-questions::-ms-fill-upper {
    background: rgba(255, 255, 255, 0.3);
    border-radius: 8px;
}

#max-questions::-ms-thumb {
    width: 24px;
    height: 24px;
    background: rgba(94, 242, 178, 0.8);
    border-radius: 50%;
    cursor: pointer;
    border: 2px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 2px 8px rgba(94, 242, 178, 0.4);
}

#max-questions::-ms-thumb:hover {
    background: rgba(94, 242, 178, 1);
    box-shadow: 0 4px 12px rgba(94, 242, 178, 0.6);
    border-color: rgba(255, 255, 255, 0.5);
}

/* Firefox-specific fixes */
@-moz-document url-prefix() {
    #max-questions {
        background: rgba(255, 255, 255, 0.3);
        border: 1px solid rgba(255, 255, 255, 0.3);
        outline: none;
        height: 8px;
    }

    #max-questions:focus {
        border: 1px solid rgba(94, 242, 178, 0.5);
        outline: none;
    }

    #max-questions-control {
        background: rgba(255, 255, 255, 0.15);
        border: 1px solid rgba(255, 255, 255, 0.3);
    }
}

/* Additional browser compatibility */
input[type="range"] {
    box-sizing: border-box;
}

/* Ensure thumb works on all browsers */
#max-questions {
    background-clip: padding-box;
}

/* Fallback for very old browsers */
@supports not (appearance: none) {
    #max-questions {
        background: rgba(255, 255, 255, 0.5) !important;
        border: 2px solid rgba(255, 255, 255, 0.7) !important;
        border-radius: 12px !important;
        padding: 6px !important;
        height: 20px !important;
    }

    #max-questions-control {
        background: rgba(255, 255, 255, 0.2) !important;
        border: 2px solid rgba(255, 255, 255, 0.4) !important;
    }
}