/* Base styles are now primarily handled by Tailwind classes in HTML */
/* Custom scrollbar for dark mode (optional, for webkit browsers) */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background-color: #e2e8f0; /* slate-200 */
}
.dark ::-webkit-scrollbar-track {
    background-color: #334155; /* slate-700 */
}
::-webkit-scrollbar-thumb {
    background-color: #94a3b8; /* slate-400 */
    border-radius: 9999px;
}
.dark ::-webkit-scrollbar-thumb {
    background-color: #64748b; /* slate-500 */
}
::-webkit-scrollbar-thumb:hover {
    background-color: #64748b; /* slate-500 */
}
.dark ::-webkit-scrollbar-thumb:hover {
    background-color: #475569; /* slate-600 */
}

.text-display-area {
    white-space: pre-wrap; 
    line-height: 1.85;
}

.blank {
    display: inline-block;
    border-bottom-width: 1.5px;
    border-bottom-style: dashed;
    margin: 0 1px;
    padding: 0 1px;
    text-align: center;
    font-weight: 600; /* semibold */
    cursor: pointer;
    transition: background-color 0.2s;
    vertical-align: baseline; 
    white-space: nowrap; 
    overflow: hidden;
}

.revealed-in-place {
    display: inline-block;
    border-bottom: 1.5px solid transparent;
    margin: 0 1px;
    padding: 0 1px;
    font-weight: 600; /* semibold */
    border-radius: 3px;
    cursor: default;
    white-space: pre-wrap; 
    vertical-align: baseline;
}

.toast-message {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
}

/* Range slider custom styles */
input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 8px;
    border-radius: 4px;
    background-color: #cbd5e1; /* slate-300 */
    outline: none;
    opacity: 0.7;
    transition: opacity .2s;
}

.dark input[type="range"] {
    background-color: #475569; /* slate-600 */
}

input[type="range"]:hover {
    opacity: 1;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background-color: #0ea5e9; /* sky-500 */
    cursor: pointer;
    border: 2px solid white;
}

.dark input[type="range"]::-webkit-slider-thumb {
    background-color: #38bdf8; /* sky-400 */
    border-color: #334155; /* slate-700 */
}

input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background-color: #0ea5e9; /* sky-500 */
    cursor: pointer;
    border: 2px solid white;
}

.dark input[type="range"]::-moz-range-thumb {
    background-color: #38bdf8; /* sky-400 */
    border-color: #334155; /* slate-700 */
}

/* Problem set selector styles */
.problem-set-button {
    transition: all 0.2s ease-in-out;
}

.problem-set-button:hover {
    transform: translateY(-1px);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.problem-set-button.border-sky-400 {
    box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.2);
}

.dark .problem-set-button.border-sky-400 {
    box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.3);
}

.problem-set-checkbox {
    transition: all 0.2s ease-in-out;
}

.problem-set-button:hover .problem-set-checkbox {
    border-color: rgb(56, 189, 248); /* sky-400 */
}

.check-icon {
    transition: transform 0.2s ease-in-out;
}

.problem-set-button:hover .check-icon {
    transform: scale(1.1);
}

/* ダークモード対応 */
.dark .problem-set-button:hover {
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}