body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-color: #f0f0f0;
    font-family: Arial, sans-serif;
    
}

.calculator {
    background-color: #333;
    border-radius: 10px;
    padding: 20px;
    padding-bottom: 30px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
    width: 370px;
    height: 630px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.calculator-title {
    text-align: center;
    font-size: 1.2em;
    font-weight: bold;
    margin-bottom: 1px;
    color: white;
}

.display {
    background-color: #eee;
    padding: 10px;
    padding-bottom: 15px;
    margin-bottom: 0px;
    margin-top: 35px;
    border-radius: 5px;
    width: 100%;
    position: relative;
}

#main-display {
    position: absolute;
    opacity: 0;
    pointer-events: none;
    width: 0;
    height: 0;
    border: 0;
    padding: 0;
    margin: 0;
}

#expr-display {
    min-height: 0;
    font-size: 1.05rem;
    text-align: right;
    color: #666;
    padding-bottom: 0;
    line-height: 1.2;
}

#expr-display:empty {
    min-height: 0;
    padding-bottom: 0;
}

#expr-display:not(:empty) {
    min-height: 18px;
    padding-bottom: 4px;
}

#main-display-visual {
    width: 100%;
    min-height: 60px;
    font-size: 2.5rem;
    text-align: right;
    color: #333;
    line-height: 1.15;
    word-break: break-all;
}

#sub-display {
    min-height: 30px;
    font-size: 1rem;
    text-align: right;
    color: #666;
    padding-top: 2px;

}

.settings {
    margin-top: 30px;
    margin-bottom: 20px;
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    font-size: 1rem;
    width: 100%;
}

.setting-block {
    width: 30%;
    display: flex;
    flex-direction: column;
    margin-right: 3%;
}

/* 라벨 텍스트를 진하게 설정 */
.setting-block label {
    font-weight: bold; /* 텍스트를 진하게 설정 */
    font-size: 1rem; /* 기본 크기 유지 */
    color: inherit; /* 부모 요소의 색상 상속 */
}

#decimal-places, #rounding-method {
    width: 100%;
    padding: 7px;
    border-radius: 5px;
    border: none;
    font-size: 1rem;
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 6px;
    width: 100%;
}

button {
    min-height: 44px;
    padding: 10px 10px;
    font-size: clamp(1.1rem, 3.5vw, 1.4rem);
    font-weight: 600;
    line-height: 1.1;
    border: none;
    background-color: #4a4a4a;
    color: white;
    cursor: pointer;
    border-radius: 5px;
    transition: background-color 0.3s;
    
}

button:hover {
    background-color: #5a5a5a;
}

.small-text {
    font-size: clamp(1.0rem, 3.2vw, 1.3rem);
    letter-spacing: -0.01em;
    white-space: nowrap;
}

@media (max-width: 480px) {
    .calculator {
        width: min(95vw, 420px);
        height: auto;
    }

    .buttons {
        grid-template-columns: repeat(4, 1fr);
        gap: 8px;
    }

    button {
        min-height: auto;
        padding: 10px;
    }

    #expr-display {
        min-height: 0;
        font-size: 0.92rem;
    }

    #expr-display:not(:empty) {
        min-height: 14px;
    }

    #main-display-visual {
        min-height: 50px;
        font-size: 2rem;
    }

    #sub-display {
        min-height: 22px;
        font-size: 0.88rem;
    }
}

/* 숫자 버튼 (data-value가 있는 버튼들) */
button[data-value],
button[data-action="appendDoubleZero"],
button[data-action="appendDecimal"] {
    background-color: #ffffff;
    color: #000;
}

/* 숫자 버튼 hover */
button[data-value]:hover,
button[data-action="appendDoubleZero"]:hover,
button[data-action="appendDecimal"]:hover {
    background-color: #f0f0f0;
}

/* 숫자와 사칙연산 기호 버튼을 진하게 */
button[data-value],
button[data-action="appendDoubleZero"],
button[data-action="appendDecimal"],
button[data-action="operate"] {
    font-weight: 900;
    /* font-size: clamp(1.5rem, 4.2vw, 1.7rem); */
    font-size: 1.7rem; /* 크기 축소 */
}

/* 숫자 외 기능 버튼 (= 버튼 제외) */
button:not([data-value]):not([data-action="appendDoubleZero"]):not([data-action="appendDecimal"]):not([data-action="calculate"]) {
    background-color: #5a5a5a;
}

/* 숫자 외 기능 버튼 hover (= 버튼 제외) */
button:not([data-value]):not([data-action="appendDoubleZero"]):not([data-action="appendDecimal"]):not([data-action="calculate"]):hover {
    background-color: #6c6c6c;
}

/* 기능 버튼 텍스트 크기 별도 설정 */
button[data-action="taxPlus"],
button[data-action="taxMinus"],
button[data-action="toggleSign"],
button[data-action="percentage"],
button[data-action="memoryAdd"],
button[data-action="memorySub"],
button[data-action="memoryRecall"],
button[data-action="memoryClear"],
button[data-action="clearAll"],
button[data-action="clearEntry"] {
    font-size: clamp(1.0rem, 3.2vw, 1.3rem); /* 원하는 크기로 조절 */
    font-weight: 600;
}

/* = 버튼 스타일 (크기 별도 설정) */
button[data-action="calculate"] {
    background-color: #ffffff;
    color: #000000;
    font-size: clamp(1.5rem, 4.5vw, 1.8rem); /* = 기호 크기 별도 설정 */
    font-weight: bold;
}

/* = 버튼 hover 효과 */
button[data-action="calculate"]:hover {
    background-color: #f0f0f0;
}

/* Tax 버튼 */
button[data-action="taxPlus"],
button[data-action="taxMinus"] {
    font-size: clamp(1.0rem, 3.2vw, 1.3rem);
}

/* 메모리 버튼 */
button[data-action="memoryAdd"],
button[data-action="memorySub"],
button[data-action="memoryRecall"],
button[data-action="memoryClear"] {
    font-size: clamp(1.0rem, 3.2vw, 1.3rem);
}

/* 기타 기능 버튼 */
button[data-action="toggleSign"],
button[data-action="percentage"],
button[data-action="clearAll"],
button[data-action="clearEntry"] {
    font-size: clamp(1.0rem, 3.2vw, 1.3rem);
}



/* 버튼 클릭 효과 */
button:active {
    transform: scale(0.96);
}



#color-select {
    width: 100%;
    padding: 7px;
    border-radius: 5px;
    border: none;
    font-size: 1rem;
    background-color: white;
}