* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: var(--font-family);
    user-select: none;
}
body {
    background: var(--bg-color);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    transition: background 0.5s ease;
}
#petal-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    pointer-events: none;
    z-index: 0;
}
.petal {
    position: absolute;
    top: -50px;
    font-size: 20px;
    animation: fall linear forwards;
    opacity: 0.8;
}
@keyframes fall {
    0% {
        transform: translateY(-20px) rotate(0deg) scale(0.8);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    100% {
        transform: translateY(110vh) rotate(360deg) scale(1.2);
        opacity: 0;
    }
}
.calculator-wrapper {
    position: relative;
    z-index: 10;
}
.calculator {
    background: var(--calc-bg);
    padding: var(--calc-padding);
    border-radius: calc(var(--btn-radius) * 1.5);
    box-sizing: var(--shadow);
    backdrop-filter: var(--backdrop);
    width: 300px;
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.2);
}
.display {
    background: var(--display-bg);
    text-align: right;
    padding: 15px 10px;
    margin-bottom: 15px;
    min-height: 90px;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    word-wrap: break-word;
    word-break: break-all;
}
.previous-operand {
    color: var(--text-muted);
    font-size: 1.2rem;
    min-height: 1.5rem;
}
.current-operand {
    color: var(--text-main);
    font-size: 2.5rem;
    font-weight: 700;
}
.keypad {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-gap: var(--grid-gap);
    transition: grid-gap 0.3s ease;
}
.btn {
    cursor: pointer;
    border: none;
    outline: none;
    background: var(--btn-bg);
    color: var(--text-main);
    font-size: 1.25rem;
    font-weight: 600;
    padding: 14px;
    border-radius: var(--btn-radius);
    transition: all 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
}
.btn:hover {
    background: var(--btn-hover);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}
.btn:active {
    transform: translateY(1px);
}
.operator {
    background: var(--btn-operator);
    color: #fff;
}
.operator:hover {
    background: var(--btn-operator-hover);
}
.action {
    background: var(--btn-action);
    color: #fff;
}
.equals {
    background-color: var(--btn-equals);
    color: #fff;
    font-size: 1.75rem;
}
[data-theme="candy"] .equals {
    color: white;
}
.span-two-horizontal {
    grid-column: span 2;
}
.span-two-vertical {
    grid-row: span 2;
}
.ripple {
    position: absolute;
    border-radius: 50%;
    transform: scale(0);
    animation: ripple 0.6s linear;
    background-color: rgba(255, 255, 255, 0.7);
}
@keyframes ripple {
    to {
        transform: scale(4);
        opacity: 0;
    }
}
.icon-btn {
    position: absolute;
    top: -45px;
    right: 0;
    background: var(--calc-bg);
    color: var(--text-main);
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    font-size: 1.2rem;
    cursor: pointer;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease;
}
.icon-btn:hover {
    transform: rotate(90deg) scale(1.1);
}
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(5px);
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
    z-index: 100;
}
.modal-overlay.active {
    opacity: 1;
    pointer-events: all;
}
.modal-content {
    background: var(--calc-bg);
    padding: 30px;
    border-radius: 20px;
    width: 90%;
    max-width: 400px;
    color: var(--text-main);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
    transform: translateY(20px);
    transition: transform 0.3s ease;
}
.modal-overlay.active .modal-content {
    transform: translateY(0);
}
.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 25px;
}
.modal-header .icon-btn {
    position: relative;
    top: 0;
    box-shadow: none;
}
.modal-header .icon-btn:hover {
    transform: rotate(90deg);
}
.settings-group {
    margin-bottom: 20px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.toggle-group {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
}
select {
    padding: 10px;
    border-radius: 10px;
    border: 1px solid var(--text-muted);
    background: var(--btn-bg);
    color: var(--text-main);
    font-family: inherit;
    font-size: 1rem;
    outline: none;
    cursor: pointer;
}
.switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 26px;
}
.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}
.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    transition: .4s;
    border-radius: 34px;
}
.slider::before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    border-radius: 50%;
    transition: .4s;
}
input:checked + .slider {
    background-color: var(--btn-equals);
}
input:checked + .slider::before {
    transform: translateX(24px);
}
@media (max-width: 400px) {
    .calculator {
        width: 100%;
        border-radius: 0;
        min-height: 100vh;
        display: flex;
        flex-direction: column;
        justify-content: flex-end;
    }
    .icon-btn {
        top: 20px;
        right: 20px;
    }
}