.calc-window {
    position: fixed;
    top: 100px;
    right: 20px;
    width: 360px;
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(15px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 1.25rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    z-index: 10000;
    display: none;
    flex-direction: column;
    overflow: hidden;
    user-select: none;
    font-family: 'Inter', sans-serif;
    transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.calc-window.scientific {
    width: 600px;
}

.calc-header {
    padding: 1rem;
    background: rgba(255, 255, 255, 0.05);
    cursor: grab;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.calc-header:active {
    cursor: grabbing;
}

.calc-title {
    color: #fff;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.calc-controls i {
    color: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    margin-left: 10px;
    transition: color 0.2s;
}

.calc-controls i:hover {
    color: #fff;
}

.calc-display-area {
    padding: 1.5rem;
    text-align: right;
    background: rgba(0, 0, 0, 0.2);
}

.calc-history {
    color: rgba(255, 255, 255, 0.4);
    font-size: 0.8rem;
    min-height: 1.2rem;
    margin-bottom: 5px;
}

.calc-main-display {
    color: #fff;
    font-size: 2.5rem;
    font-weight: 300;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.calc-body {
    padding: 1.25rem;
    display: flex;
    gap: 1.25rem;
}

.calc-sci-grid {
    display: none;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    border-right: 1px solid rgba(255, 255, 255, 0.1);
    padding-right: 1.25rem;
}

.calc-window.scientific .calc-sci-grid {
    display: grid;
}

.calc-std-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    flex: 1;
}

.calc-btn {
    border: none;
    border-radius: 0.75rem;
    padding: 0.85rem 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    color: #fff;
    background: rgba(255, 255, 255, 0.05);
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 50px;
}

.calc-btn:hover {
    background: rgba(255, 255, 255, 0.12);
    transform: translateY(-2px);
    color: #fff;
}

.calc-btn:active {
    transform: translateY(0);
}

.calc-btn.op {
    background: rgba(59, 130, 246, 0.15);
    color: #60a5fa;
}

.calc-btn.eq {
    background: #3b82f6;
    color: #fff;
    grid-row: span 2;
    height: 100%;
}

.calc-btn.sci {
    background: rgba(168, 85, 247, 0.08);
    color: #a855f7;
    font-size: 0.85rem;
}

.calc-btn.util {
    background: rgba(16, 185, 129, 0.1);
    color: #10b981;
    font-weight: 800;
    font-size: 0.75rem;
}

.calc-mode-toggle {
    grid-column: span 1;
    font-size: 0.65rem;
    background: rgba(255, 255, 255, 0.03);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: rgba(255, 255, 255, 0.6);
    line-height: 1;
    padding: 0.5rem;
}